Master Gas Cheap Boiler Repairs London
Has your boiler broken down, leaving you with no other option than to get it repaired? This is quite disappointing but you just have to find a way to get things done and return it to its optimal level. Are you looking for a cheap boiler repair that will give you value for your money? We are here to provide that for you.
We are a boiler repairer that understands how much and how fast you need to get this repair done. And that is why we’re offering you this boiler repair service at the best possible price. We also know the value of having a boiler that is always there to provide you heat when needed. With this known fact, our boiler repair engineers don’t leave anything untouched while repairing your boiler. They take into consideration all the possible factor that could cause faults or damages in the nearest future and eliminate them.
Improving the effciency of your boiler
To improve the efficiency of your boiler, the first thing we do carry out is the diagnosis of your boiler. This allows us to access your boiler from within and check all the possible faults and how they can be fixed the right way. This way, nothing will be hidden to our engineers anymore as they repair your boiler.
Another benefit you will be getting from us is our quick response. Being very timely, we can reach where you are in any part of London within just an hour. This is made possible because we have engineers spread across the city waiting to receive your messages.
Why Choose Us
- Having spent over a decade repairing boilers of all kinds, we have the experience needed to fix whatever problem your boiler might be having.
- Our engineers and other personnel are well trained, certified and fully pack with the right tools to give you their possible best.
- We being a boiler repairer based in London means we are within your reach any day, any time ready to serve you.
Get In Touch
You can contact Master Gas 24 hours a day and a member of our team will only be pleased to receive your call request.
By using Master Gas you can rest assured that your job will be completed by experts and to your satisfaction, not forgetting, of course, our workmanship guarantee. Call today
0203 667 7276
Glow Error Codes
| Boiler Model | Fault Code | Cause of Problem |
|---|---|---|
| Betacom | Red LED on | Lockout – low water pressure (increase pressure to 1.5bar) and reset boiler |
| Betacom | Red LED flashing | Overheat – check both overheat stats |
| Betacom | Yellow LED flashing | Turn domestic hot water (DHW) control knob into temperature range and turn central heating (CH) temperature control knob into power (reset position) and wait for minimum of 30 seconds before turning into either summer or temperature position |
| Betacom | Yellow LED on | Flame present on the burner |
| Betacom | Green LED on | Boiler ready for operation |
| Betacom | Green LED off | No power to boiler – Check for 230volts into the appliance, check fuse on printed circuit board (PCB) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F00 / F10 / F71 | Flow heating temperature sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F01 / F11 | Return heating temperature sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F20 | Overheating fault |
| Betacom / Ultracom₂ cxi / sxi / hxi / 35 / Flexicom cx / hx / sx | F9 / F22 | Low water pressure (or ignition temperature rise too slow) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F26 / F77 | Fault in gas valve |
| Betacom / Ultracom₂ cxi / sxi / 35 / CI / hxi / Xtramax HE | F27 / F16 | Flame detection fault |
| All Boilers | F28 / F1 / F4 | Ignition fault (flame detection) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F29 | Loss of flame during operation |
| Betacom / Ultracom₂ cxi / sxi / 35 | F32 | Incorrect air pressure |
| Betacom / Ultracom₂ cxi / sxi / 35 | F49 | EBUS voltage fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F61 / F62 / F63 / F64 / F65 / F67 | Fault in the main board |
| Betacom / Ultracom₂ cxi / sxi / 35 | F68 | Fluctuation of flame signal |
| Betacom / Ultracom₂ cxi / sxi / 35 | F70 | User interface incompatible with the main board |
| Betacom / Ultracom₂ cxi / sxi / 35 | F72 / F84 | Permanent temperature difference between flow and return heating sensors |
| Betacom / Ultracom₂ cxi / sxi / 35 | F73 / F74 | Heating circuit pressure sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F76 | Thermal fuse fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F83 | Thermal fuse fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F85 | Flow and Return heating sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F86 | Underfloor heating contact fault |
| All Boilers | ERR / F12 / F18 | User interface fault |
| Betacom c | Temperature 30 flashing | Fault on central heating (CH) thermistor |
| Betacom c | Temperature 40 flashing | Fault on DHW thermistor |
| Betacom c | Temperature 50 flashing | Fault on outside sensor |
| Betacom c | Temperature 60 flashing | Low system pressure |
| Betacom c | Temperature 70 flashing | Fault on APS |
| Betacom c | Temperature 80 flashing | Overheat open circuit |
| Betacom c | Temperature 90 flashing | Flame or gas failure |
| Compact e / s | No DHW | Check dhw microswitch / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | No C/H | Check dhw microswitch if dhw demand led is lit / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | No C/H but boiler is firing | Check divertor motor and cartridge / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | Boiler locks out within 10 seconds | Check pump proving switch, air pressure switch and overheat state / Check pump proving switch, air pressure switch and overheat stat |
| Compact e / s | Poor burner pressure | Check burner pressure/ignition adjustment pots on PCB |
| Ci Range (plus) / Si range | F2 | Fan/APS |
| All Boilers | F5 | Overheat Fault |
| All Boilers | F6 | Central heating flow thermistor |
| All Boilers | F7 | Domestic hot water thermistor |
| All Boilers | F8 | Tank thermistor fault |
| sxi / si / ci (plus) range / Xtramax HE | F9 | Water pressure sensor fault (please contact GW technical department for further information) |
| All boilers | F10 | Central return flow thermistor |
| All boilers | F11 | Main board connection fault |
| Ci (plus) / cxi / hxi / si / sxi range | F12 | Connection fault between main printed circtuit board (PCB) and display PCB |
| Ci (plus) / cxi / hxi / si / sxi range | F13 | Main pcb connection fault |
| Ci (plus) / cxi / hxi / si / sxi range | F14 | Central heating flow temperature > 95 degrees |
| Ci (plus) / cxi / si / sxi range | F15 | Gas valve stepper motor fault |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F17 | Power supply is less than 170v |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F19 | Central heating thermistor unplugged |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F20 | Software incompatibility |
| cxi / hxi / sxi range / Flexicom cx | F24 | Central heating return temperature > 90 degrees |
| cxi / hxi / sxi / Xtrafast 96/120 / Xtrafast 96/120E1 | F25 / F26 / F11 | Poor circulation |
| ci range | F3 | Air fault |
| ci range | F3 | Air fault |
| cxi / sxi / hxi range/ Xtramax HE | F2 / F3 | Fan |
| cxi / sxi range / Flexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxi / Ultrapower sxi | F3 | Fan unable to reach ignition speed |
| Flexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxi | F9 | Water pressure sensor fault, blocked flow filter or pump fault |
| Flexicom cx / hx / sx | F11 | Flow and or return thermistor fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F13 | PCB memory or sensing fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F14 | Gas valve control defective |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F15 | E-bus voltage failure |
| All boilers | F25 / F23 | Circulation fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F43 | Generic error |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F70 | Software incompatible |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F73 | Unable to see pump activate |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F77 | Condensate pump error (optional) |
| hxi range | F9 | Earlier models only (please contact GW technical department for further information) |
| hxi range | F9 | Earlier models only (please contact GW technical department for further information) |
| Ultracom₂ 35 Store | F02 / F12 | Hot water temperature sensor fault |
| Ultracom₂ 35 Store | F03 / F13 / F79 | Storage tank temperature sensor fault |
| Ultracom₂ 35 Store | F81 | Overheating of hot water circuit |
| All Ultracom | No display or Er | loose connection X51 |
| Xtramax HE Range | F24 | Cental heating return temperature > 90 degrees |
| Xtramax HE Range | F25 | Maximum temperature rise slope |
| Xtramax HE Range | F26 | Maximum delta temperature |
| Xtrafast 96/120 Range | F00 | No fault/td> |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F00 | No fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F02 | Air flow fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F05 | Overheating |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F06 | Central heating thermistor/wiring fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F08 | Storage vessel thermistor/wiring fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F09 | System pressure sensor fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F10 | Fan fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F13 | Main printed circuit board (PCB) fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F14 | Central heating flow temperature > 97 degrees |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F15 | Gas mechanism fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F20 | Communication fault |
| Fault Code | Cause of Problem |
|---|---|
| F.00 | Flow temperature sensor |
| F.00 | Flow temperature sensor |
| F.10 | Flow temperature sensor short circuit |
| F.11 | Flow temperature sensor short circuit |
| F.12 and F.91 | Cylinder temperature sensor short circuit |
| F.13 | Domestic hot water cylinder temperature sensor short circuit |
| F.20 | Safety switch-off – overheating temperature reached |
| F.22 | Safety switch-off – low water pressure in the boiler |
| F.23 | Safety switch-off – temperature difference too great (NTC1/NTC2) |
| F.24 | Safety switch-off – temperature rise too fast |
| F.25 | Safety switch-off – flue gas temperature too high |
| F.27 | Safety switch-off – fault in flame detection |
| F.28 | Ignition unsuccessful when starting up |
| F.29 | Flame loss |
| F.32 | Fan frost protection function active – fan speed outside the tolerance values |
| F.33 | Fan frost protection function active – air pressure switch fault |
| FA9 | eBUS fault – voltage too low |
| F.61 | Gas valve control system fault |
| F.82 | Gas valve switch-off control fault |
| F.83 | EEPROM fault – electronics defective |
| F.64 | Electronics/sensor/analogue-to-digital converter fault |
| F.85 | Electronics temperature too high |
| F.67 | Value sent back by ASIC is incorrect (flame slgnal) |
| F.88 | Unstable flame (analogue input), underfloor heating contact or gas valve fault |
| F.70 | Invalid product code (DSN) |
| F.71 | Flow/return temperature sensor |
| F.72 | Deviation in the water pressure sensor/return temperature sensor |
| F.73 | Water pressure sensor not connected or has short-circuited |
| F.74 | Electrical problem in the water pressure sensor |
| F.75 | Pressure sensor fault |
| F.78 | The safety cut-out in the primary heat exchanger is defective |
| F.77 | Fault: Condensate or smoke |
| F.78 | Interruption to domestic hot water (DHW) outlet sensor at external controller |
| F.83 | Burner temperature sensor fault |
| F.84 | Flow/return temperature sensor fault |
| F.85 | Temperature sensor fault |
| F.87 | Electrodes fault |
| F.89 | Pump fault |
| Connection | No communication between the printed circuit board (PCB) and the user interface |
Call Us On
Baxi Boiler Error Codes
| Fault Code | Possible Cause |
|---|---|
| E20 | Central heating NTC error |
| E28 | Error with the NTC (Negative Temperature Coefficient) flue, air pressure switch or blocked flue or condensate |
| E50 | Hot water NTC (Negative Temperature Coefficient) error |
| E110 | Thermostat operated safety |
| E119 | Water pressure switch error – not operated. |
| E125 | Primary circuit error circulation fault |
| E130 | Flue NTC (Negative Temperature Coefficient) operation error |
| E133 | Gas supply error or flame failure |
| E160 | Fan or fan wiring error |
| E193 | Pre-circulation error |
| Fault Code | Possible Cause |
|---|---|
| 110 | Overheated – try bleeding your radiators |
| 117 | Water pressure too high |
| 118 | Water pressure too low |
| 125 | Water circulation fault |
| 133 | Safety time to establish flame exceeded |
| E10 | Outdoor sensor error |
| E20 | Central heating thermistor sensor fault |
| E28 | Flue thermistor fault |
| E54 | Domestic hot water (DHW) flow sensor fault |
| E78 | Water pressure sensor fault |
| E100 | Internal clock time error on printed circuit board (PCB) |
| E109 | Poor circulation |
| 110 | Overheat – try bleeding your radiators |
| 111 | Maximum limit of flow temperature |
| 117 | Water pressure too high |
| 118 | Water pressure too low |
| 119 | System pressure too low |
| 125 | Water circulation fault |
| 127 | Legionella (cause of Legionnaires’ disease) protection temperature not reached |
| 128 | Loss of flame during operation |
| 133 | Safety time to establish flame exceeded |
| 153 | Forced reset unit unlocked |
| 160 | Fan fault |
| 162 | Air pressure switch error |
| 164 | Pressure Sensor Error (UK) – Heating flow switch error (Ireland) |
| 166 | Air pressure switch fault |
| 270 | Dry fire |
| 432 | Earth connector error |
| 433 | Heat exchanger temperature exceeded (greater than 95 degrees) |
| Fault Code | Possible Cause |
|---|---|
| 1 green flash | Boiler temperature reached. No action required. |
| 3 green flashes | Temporary flame loss. Boiler will self reset, if fault continues you will see 3 red flashes. |
| 4 green flashes | Communication error between printed circuit board (PCB) and control. Temporary error, will self reset. |
| 5 green flashes | Parameter error on printed circuit board (PCB). Temporary error, will self reset |
| 6 green flashes | Miscellaneous error. Temporary error, will self reset. |
| 1 red flash | Sensor error, temperature fault or flow fault. |
| 2 red flashes | Boiler overheat tripped |
| 3 red flashes | Ignition fault. Boiler has attempted to light 5 times and failed. |
| 4 red flashes | Fan fault |
| 5 red flashes | Parameter storage unit (PSU) error. |
| 6 red flashes | Miscellaneous error. |
| Fault Code | Possible Cause |
|---|---|
| E10 | Outdoor sensor fault |
| E20 | Central heating thermistor sensor error |
| E28 | Flue thermistor error |
| E110 | Boiler overheat error |
| E119 | Low water pressure error |
| E125 | Primary water circulation error |
| E131 | Flue overheat lockout error |
| E133 | Ignition error |
| E160 / E161 | Fan error |
| E164 | Pressure sensor fault |
| E167 | Printed circuit board (PCB) error |
| E168 | Printed circuit board (PCB) lockout error |
| E193 | Circulation error |
| Fault Code | Possible Cause |
|---|---|
| H.01 – .00 | Loss of communication between gas valve and boiler board. Possible fault in air/gas unit or loose connection to gas valve. |
| H.01 – .05 | Difference between the flow and return temperature is too high, sensor error or insufficient circulation. |
| H.01 – .08 | Sensor fault, flow temperature increasing too fast in heating mode or insufficient circulation. |
| H.01 – .14 | Maximum flow temperature value exceeded or insufficient circulation – temporary fault. |
| H.01 – .18 | No water circulation, insufficient circulation or sensor error. |
| H.01 – .21 | Temporary error – flow temperature increasing too fast in domestic hot water (DHW) mode, insufficient circulation or sensor error. |
| H.02 – .02 | Temporary error – no input of parameters C1/C2. Printed circuit board (PCB) not configured. |
| H.02 – .03 | Temporary error- incorrect configuration settings C1/C2. |
| H.02 – .04 | Temporary error- parameter fault. Incorrect parameters. |
| H.02 – .06 | Temporary error caused by system water pressure, water leak on boiler, water leak on system. |
| H.03 -.00 | Temporary error with communication, negative temperature coefficient thermostat (NTC) or flue sensor. Sensor could also be unconnected or have a bad connection. |
| H.03 – .01 | Communication error with the printed circuit board (PCB) |
| H.03 – .02 | Flame error – no flame during operation. |
| E.00 – .04 | Return temperature sensor open-circuit. Sensor not or badly connected. |
| E.00 – .05 | Return temperature sensor short-circuit. Sensor not connected or badly connected. |
| E.01 – .02 | Temperature measured by return sensor greater than flow sensor. |
| E.01 – .04 | Loss of flame detected 5 times in 24 hours (with burner on). |
| E.01 – .11 | Incorrect fan speed – external draught over the boiler or defective gas/air unit. |
| E.01 – .12 | Requires reset – temperature measured by return sensor greater than flow temperature. |
| E.01 – .17 | Reset the boiler – no circulation, sensor fault either not connected or has a bad connection. |
| E.01 – .20 | Maximum flue gas temperature reached. No circulation or sensor fault. |
| E.02 – .00 | Reset button has been pressed. |
| E.02 – .07 | No or low system water pressure. system pressure less than 0.5bar |
| E.02 – .16 | Permanent fault caused by channel service unit (CSU) time-out or printed circuit board (PCB) damage. |
| E.02 – .17 | Loss of communication between gas valve and boiler printed circuit board (PCB) or fault in air/gas unit. |
| E.02 – .19 | Jumper 1 changed – check position of jumper 1. |
| E.02 – .20 | Jumper 2 changed – check position of jumper 2. |
| E.02 – .21 | Jumper 3 changed – check position of jumper 3. |
| E.02 – .47 | Wiring to external device error. |
| E.02 – .48 | Configuration to external device unsuccessful – check pairing to external device. |
| E.04 – .00 | Gas valve error – gas valve not detected. |
| E.04 – .01 | Flow temperature sensor short-circuited. Sensor not or badly connected, bad connection or sensor fault. |
| E.04 – .02 | Permanent fault. Flow temperature sensor open-circuited, sensor not or badly connected, bad connection or sensor fault. |
| E.04 – .03 | Permanent fault. Critical flow temperature reached, non-existent or insufficient circulation. |
| E.04 – .04 | Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault. |
| E.04 – .05 | Permanent fault. Flue temperature sensor short-circuited, sensor not or badly connected, bad connection or sensor fault. |
| E.04 – .06 | Permanent fault. Critical flue gas temperature value reached, no circulation or sensor fault. |
| E.04 – .08 | Permanent fault. Maximum safe temperature value reached, safety thermostat open-circuited, no circulation, sensor not or badly connected, bad connection or sensor fault. |
| E.04 – .10 | Failure to light (could be gas supply issue). |
| E.04 – .12 | Permanent fault. False flame signal, short-term fluctuation of the mains, ionization current present even though there is no flame, the burner remains very hot (CO2 too high) or defective gas/air unit. |
| E.04 – .13 | Permanent fault. Fan rotor blocked, fan seized or wiring to fan damaged. |
| E.04 – .17 | Permanent fault. Problem with gas valve or defective gas/air unit. |
| Fault Code | Possible Cause |
|---|---|
| E09 | Gas valve connection cable. |
| E10 | External probe fault. |
| E12 | Differential water flow switch fault (still open). |
| E13 | Differential water flow switch fault (still closed). |
| E15 | Gas valve command fault. |
| E20 | Central heating negative temperature coefficient (NTC) thermostat fault. |
| E28 | Flue negative temperature coefficient (NTC) thermostat fault. |
| E40 | Central heating return negative temperature coefficient (NTC) thermostat fault. |
| E50 | Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (tank boiler) (s.c.) or DHW NTC sensor fault (tank boiler) (o.c.). |
| E83/E84/E85/E86/E87 | No communication. |
| E109 | Pre-circulation fault. |
| E110 |
|
| E118 | Primary system water pressure too low (< 0.5 bar). |
| E125 | Circulation fault (primary). |
| E128 | Frequent flame failure (12 times). |
| E129 | Safety error for frequently loss of flame with max correction during the ignition during Calibration Function. |
| E130 | Flue thermostat sensor tripped (lockout). |
| E133 | Failure to light (could be a gas supply issue). |
| E134 | Elapsed time gas valve open without gas (short request in a short period) |
| E135 | Interruption of gas supply (internal error). |
| E154 | Flow/return sensor temperature test. |
| E160 | Fan or fan wiring fault. |
| E163 | Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (s.c.) or DHW NTC sensor fault (o.c.). |
| E270 | Circulation fault (dry fire). |
| E317 | Wrong power supply electrical frequency (Hz). |
| E321 | Hot water negative temperature coefficient (NTC) fault. |
| E384 | False flame. |
| E385 | Under voltage. |
| E430 | Water pressure temporary test. |
| E430 + Flame ‘crossed’ | Water pressure test failed. |
| Fault Code | Possible Cause |
|---|---|
| 1 Green Flash | Boiler temperature reached – no action required |
| 3 Green Flashes | Temporary flame loss – this is a temporary error, the system should reset on its own |
| 4 Green Flashes | Communication error between printed circuit board (PCB) and Control – this is a temporary error, the system should reset on its own |
| 5 Green Flashes | Parameter error on parameter storage unit (PSU) or printed circuit board (PCB) – this is a temporary error, the system should reset on its own. |
| 6 Green Flashes | Miscellaneous error |
| 1 Red Flash | Sensor error, sensor fault, temperature fault or flow fault – this is a temporary error, the system should reset on it’s own. |
| 2 Red Flashes | Boiler overheat tripped |
| 3 Red Flashes | Ignition fault. Boiler has attempted to light 5 times and failed |
| 4 Red Flashes | Fan Fault |
| 5 Red Flashes | Parameter storage unit (PSU) error |
| 6 Red Flashes | Miscellaneous |
| Fault Code | Possible Cause |
|---|---|
| E0 | Temperature sensor fault |
| E1 | Overheated – try bleeding your radiators |
| E2 | Poor circulation – try bleeding your radiators |
| E3 | Printed circuit board (PCB) fault |
| E4 | Ignition failure – try bleeding your radiators |
| E10 | Poor/No circulation |
| E12 | Printed circuit board (PCB) Fault |
| E13 | Heat exchanger thermal fuse tripped |
| E83 / 84 / 85 / 86 / 87 | Fan fault normally E8 |
| Fault Code | Possible Cause |
|---|---|
| E53 | Poor combustion – flue terminal may be blocked |
| E110 | Overheated – try bleeding your radiators |
| E117 | System water pressure high – try bleeding water from your radiators |
| E118 | System water pressure low |
| E125 | Overheat – try bleeding your radiators |
| E133 | Gas supply fault |
| E4 | Ignition failure |
| E09 | Gas valve wiring fault |
| E10 | Outdoor sensor error |
| E15 | Gas valve connection fault |
| E20 | Central heating thermistor sensor fault |
| E28 | Flue thermistor fault |
| E40 | Central heating return thermistor fault |
| E53 | Flue obstruction |
| E55 | Calibration required |
| E78 | Water pressure sensor fault |
| E92 | Combustion test alarm during auto-setting |
| E109 | Poor circulation |
| E110 | Boiler overheat tripped |
| E117 | System pressure high (>2.9 Bar) |
| E118 | System pressure low(< 0.5bar) |
| E125 | Primary water circulation fault |
| E128 | Loss of flame during operation |
| E129 | Loss of flame during calibration |
| E133 | Ignition fault |
| E135 | Internal error |
| E154 | Primary flow fault |
| E160 | Fan fault |
| E270 | Dry fire |
| E317 | Wrong power supply (Hz) |
| E321 | Not water thermistor fault |
| E384 | Flame detected when gas valve off |
| E385 | Low voltage (less than 195v) |
| Fault Code | Possible Cause |
|---|---|
| FLASH FLASH ON | Fan error |
| FLASH OFF FLASH | Voltage less than 180V |
| FLASH OFF ON | Overheat lockout |
| FLASH ON FLASH | Printed circuit board (PCB) error |
| FLASH ON ON | Printed circuit board (PCB) fault |
| OFF OFF OFF | No power |
| ON FLASH FLASH | Circulation error or dry fire |
| ON FLASH ON | Thermistor error |
| ON OFF FLASH | Live and neutral reversed error |
| ON OFF ON | Ignition lockout error |
| ON ON FLASH | Printed circuit board (PCB) error |
| ON ON ON | Low voltage wiring harness error |
Glow Error Codes
| Boiler Model | Fault Code | Cause of Problem |
|---|---|---|
| Betacom | Red LED on | Lockout – low water pressure (increase pressure to 1.5bar) and reset boiler |
| Betacom | Red LED flashing | Overheat – check both overheat stats |
| Betacom | Yellow LED flashing | Turn domestic hot water (DHW) control knob into temperature range and turn central heating (CH) temperature control knob into power (reset position) and wait for minimum of 30 seconds before turning into either summer or temperature position |
| Betacom | Yellow LED on | Flame present on the burner |
| Betacom | Green LED on | Boiler ready for operation |
| Betacom | Green LED off | No power to boiler – Check for 230volts into the appliance, check fuse on printed circuit board (PCB) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F00 / F10 / F71 | Flow heating temperature sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F01 / F11 | Return heating temperature sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F20 | Overheating fault |
| Betacom / Ultracom₂ cxi / sxi / hxi / 35 / Flexicom cx / hx / sx | F9 / F22 | Low water pressure (or ignition temperature rise too slow) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F26 / F77 | Fault in gas valve |
| Betacom / Ultracom₂ cxi / sxi / 35 / CI / hxi / Xtramax HE | F27 / F16 | Flame detection fault |
| All Boilers | F28 / F1 / F4 | Ignition fault (flame detection) |
| Betacom / Ultracom₂ cxi / sxi / 35 | F29 | Loss of flame during operation |
| Betacom / Ultracom₂ cxi / sxi / 35 | F32 | Incorrect air pressure |
| Betacom / Ultracom₂ cxi / sxi / 35 | F49 | EBUS voltage fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F61 / F62 / F63 / F64 / F65 / F67 | Fault in the main board |
| Betacom / Ultracom₂ cxi / sxi / 35 | F68 | Fluctuation of flame signal |
| Betacom / Ultracom₂ cxi / sxi / 35 | F70 | User interface incompatible with the main board |
| Betacom / Ultracom₂ cxi / sxi / 35 | F72 / F84 | Permanent temperature difference between flow and return heating sensors |
| Betacom / Ultracom₂ cxi / sxi / 35 | F73 / F74 | Heating circuit pressure sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F76 | Thermal fuse fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F83 | Thermal fuse fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F85 | Flow and Return heating sensor fault |
| Betacom / Ultracom₂ cxi / sxi / 35 | F86 | Underfloor heating contact fault |
| All Boilers | ERR / F12 / F18 | User interface fault |
| Betacom c | Temperature 30 flashing | Fault on central heating (CH) thermistor |
| Betacom c | Temperature 40 flashing | Fault on DHW thermistor |
| Betacom c | Temperature 50 flashing | Fault on outside sensor |
| Betacom c | Temperature 60 flashing | Low system pressure |
| Betacom c | Temperature 70 flashing | Fault on APS |
| Betacom c | Temperature 80 flashing | Overheat open circuit |
| Betacom c | Temperature 90 flashing | Flame or gas failure |
| Compact e / s | No DHW | Check dhw microswitch / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | No C/H | Check dhw microswitch if dhw demand led is lit / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | No C/H but boiler is firing | Check divertor motor and cartridge / Check external controls, Please test for 230V on switch live contact |
| Compact e / s | Boiler locks out within 10 seconds | Check pump proving switch, air pressure switch and overheat state / Check pump proving switch, air pressure switch and overheat stat |
| Compact e / s | Poor burner pressure | Check burner pressure/ignition adjustment pots on PCB |
| Ci Range (plus) / Si range | F2 | Fan/APS |
| All Boilers | F5 | Overheat Fault |
| All Boilers | F6 | Central heating flow thermistor |
| All Boilers | F7 | Domestic hot water thermistor |
| All Boilers | F8 | Tank thermistor fault |
| sxi / si / ci (plus) range / Xtramax HE | F9 | Water pressure sensor fault (please contact GW technical department for further information) |
| All boilers | F10 | Central return flow thermistor |
| All boilers | F11 | Main board connection fault |
| Ci (plus) / cxi / hxi / si / sxi range | F12 | Connection fault between main printed circtuit board (PCB) and display PCB |
| Ci (plus) / cxi / hxi / si / sxi range | F13 | Main pcb connection fault |
| Ci (plus) / cxi / hxi / si / sxi range | F14 | Central heating flow temperature > 95 degrees |
| Ci (plus) / cxi / si / sxi range | F15 | Gas valve stepper motor fault |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F17 | Power supply is less than 170v |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F19 | Central heating thermistor unplugged |
| Ci (plus) / cxi / hxi / si / sxi range / Xtramax HE | F20 | Software incompatibility |
| cxi / hxi / sxi range / Flexicom cx | F24 | Central heating return temperature > 90 degrees |
| cxi / hxi / sxi / Xtrafast 96/120 / Xtrafast 96/120E1 | F25 / F26 / F11 | Poor circulation |
| ci range | F3 | Air fault |
| ci range | F3 | Air fault |
| cxi / sxi / hxi range/ Xtramax HE | F2 / F3 | Fan |
| cxi / sxi range / Flexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxi / Ultrapower sxi | F3 | Fan unable to reach ignition speed |
| Flexicom cx / hx / sx / hxi / Ultracom cxi / cx / hxi / sxi | F9 | Water pressure sensor fault, blocked flow filter or pump fault |
| Flexicom cx / hx / sx | F11 | Flow and or return thermistor fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F13 | PCB memory or sensing fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F14 | Gas valve control defective |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi / Xtramax HE | F15 | E-bus voltage failure |
| All boilers | F25 / F23 | Circulation fault |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F43 | Generic error |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F70 | Software incompatible |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F73 | Unable to see pump activate |
| Flexicom cx / hx / sx / Ultracom cxi / cx / hxi / sxi | F77 | Condensate pump error (optional) |
| hxi range | F9 | Earlier models only (please contact GW technical department for further information) |
| hxi range | F9 | Earlier models only (please contact GW technical department for further information) |
| Ultracom₂ 35 Store | F02 / F12 | Hot water temperature sensor fault |
| Ultracom₂ 35 Store | F03 / F13 / F79 | Storage tank temperature sensor fault |
| Ultracom₂ 35 Store | F81 | Overheating of hot water circuit |
| All Ultracom | No display or Er | loose connection X51 |
| Xtramax HE Range | F24 | Cental heating return temperature > 90 degrees |
| Xtramax HE Range | F25 | Maximum temperature rise slope |
| Xtramax HE Range | F26 | Maximum delta temperature |
| Xtrafast 96/120 Range | F00 | No fault/td> |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F00 | No fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F02 | Air flow fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F05 | Overheating |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F06 | Central heating thermistor/wiring fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F08 | Storage vessel thermistor/wiring fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F09 | System pressure sensor fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F10 | Fan fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F13 | Main printed circuit board (PCB) fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F14 | Central heating flow temperature > 97 degrees |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F15 | Gas mechanism fault |
| Xtrafast 96/120 Range / Xtrafast 96/120E1 Range | F20 | Communication fault |
| Fault Code | Cause of Problem |
|---|---|
| F.00 | Flow temperature sensor |
| F.00 | Flow temperature sensor |
| F.10 | Flow temperature sensor short circuit |
| F.11 | Flow temperature sensor short circuit |
| F.12 and F.91 | Cylinder temperature sensor short circuit |
| F.13 | Domestic hot water cylinder temperature sensor short circuit |
| F.20 | Safety switch-off – overheating temperature reached |
| F.22 | Safety switch-off – low water pressure in the boiler |
| F.23 | Safety switch-off – temperature difference too great (NTC1/NTC2) |
| F.24 | Safety switch-off – temperature rise too fast |
| F.25 | Safety switch-off – flue gas temperature too high |
| F.27 | Safety switch-off – fault in flame detection |
| F.28 | Ignition unsuccessful when starting up |
| F.29 | Flame loss |
| F.32 | Fan frost protection function active – fan speed outside the tolerance values |
| F.33 | Fan frost protection function active – air pressure switch fault |
| FA9 | eBUS fault – voltage too low |
| F.61 | Gas valve control system fault |
| F.82 | Gas valve switch-off control fault |
| F.83 | EEPROM fault – electronics defective |
| F.64 | Electronics/sensor/analogue-to-digital converter fault |
| F.85 | Electronics temperature too high |
| F.67 | Value sent back by ASIC is incorrect (flame slgnal) |
| F.88 | Unstable flame (analogue input), underfloor heating contact or gas valve fault |
| F.70 | Invalid product code (DSN) |
| F.71 | Flow/return temperature sensor |
| F.72 | Deviation in the water pressure sensor/return temperature sensor |
| F.73 | Water pressure sensor not connected or has short-circuited |
| F.74 | Electrical problem in the water pressure sensor |
| F.75 | Pressure sensor fault |
| F.78 | The safety cut-out in the primary heat exchanger is defective |
| F.77 | Fault: Condensate or smoke |
| F.78 | Interruption to domestic hot water (DHW) outlet sensor at external controller |
| F.83 | Burner temperature sensor fault |
| F.84 | Flow/return temperature sensor fault |
| F.85 | Temperature sensor fault |
| F.87 | Electrodes fault |
| F.89 | Pump fault |
| Connection | No communication between the printed circuit board (PCB) and the user interface |
Ideal Error Codes
| Fault Description | System Behaviour |
|---|---|
| L1 | Flow temperature overheat lockout or no water flow lockout |
| L2 | Ignition lockout |
| LC | 5 restarts within 15 minutes |
| L6 | False flame lockout |
| FA | Flow return reversed |
| FD | No water flow |
| F2 or FN or LN | Flame loss |
| F3 | Fan fault |
| L4 or F4 | Control / no flow thermistor fault |
| L5 or F5 | Return thermistor fault |
| F6 | Outside sensor fault |
| F7 | Low mains voltage Contact electricity provider |
| F9, L9, F8 or L8 | Printed circuit board (PCB) unconfigured or fault |
| FU | Diff greater than 50c check isolation valves are open |
| Fault Code | System Behaviour |
|---|---|
| C0 | Boiler chip card (BCC) activation fault |
| C2 | Boiler chip card (BCC) fault |
| F1 | Low water pressure |
| F2 | Flame loss |
| F3 | Fan fault |
| F4 | Flow thermistor fault |
| F5 | Return thermistor fault |
| F6 | Outside sensor failure |
| F7 | Low mains voltage |
| F9 | Unconfigured printed circuit board (PCB) |
| L1 | Flow temperature overheat or no water flow |
| L2 | Flame loss |
| L5 | 5 boiler resets in 15 minutes |
| L6 | False flame lockout |
| Fault Code | System Behaviour |
|---|---|
| 0 | The boiler is in standby mode awaiting either a central heating call or hot water demand |
| C | The boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler |
| D | The boiler has a call for hot water but the appliance has reached the desired temperature set on the boiler |
| C | The boiler is operating in central heating mode |
| d | The boiler is operating in hot water mode |
| F | The boiler is operating in frost mode |
| Fault Description | System Behaviour |
|---|---|
| L1 | Flow temperature overheat lockout or no water flow lockout |
| L2 | Ignition lockout |
| LC | 5 restarts within 15 minutes |
| L6 | False flame lockout |
| FA | Flow return reversed |
| FD | No water flow |
| F2 or FN or LN | Flame loss |
| F3 | Fan fault |
| L4 or F4 | Control / no flow thermistor fault |
| L5 or F5 | Return thermistor fault |
| F6 | Outside sensor fault |
| F7 | Low mains voltage Contact electricity provider |
| F9, L9, F8 or L8 | Printed circuit board (PCB) unconfigured or fault |
| FU | Diff greater than 50c check isolation valves are open |
| Fault Description | System Behaviour |
|---|---|
| Overheat lockout | Bleed radiators, refill system to 1.0 bar, check that radiator and boiler valves are open and reset boiler. If fault continues book an engineer. |
| Ignition lockout | Check gas appliances work and restart boiler. |
| Too many restarts | 5 starts within 15 minutes. Turn power on and off. |
| Flame on before gas on | False flame lockout. |
| Water pressure | With boiler off and system cold fill system to 1.0 bar and bleed radiators if fault continues contact an installer. |
| Fault Description | System Behaviour |
|---|---|
| Too many resets | 5 restarts within 15 minutes |
| Flame on before gas valve on | Flame on before gas valve is on |
| Flow thermistor fault | Flow thermistor error |
| Low mains voltage | Less than 185v to boiler then check voltage at boiler mains in if mains voltage is okay pump needs replacing |
| Low water pressure | Low water pressure |
| Flow return reversed | Check if the flow thermistor is correctly clipped to pipe. If not, replace flow thermistor. |
| Printed circuit board (PCB) recently replaced | Reset boiler |
| Pump rotor blocked | Unblock pump |
| Flow temperature setpoint cannot be increased to 80c | Check flow and return thermistors securely clamped to pipes check flow and return thermistor |
| Fault Description | Cause |
|---|---|
| Thermal fuse lockout | Reset the boiler |
| Too many boiler resets | 5 resets within 15 minutes. Turn power off and on. |
| Printed circuit board (PCB) replaced incorrectly | Ensure the boiler chip card (BCC) is fitted correctly. |
| Low mains voltage | Less than 160V to boiler. Contact electricity provider. |
| Low water pressure | Increase system pressure to 1.5 bar |
| Flow/Return reversed | Check if flow thermistor is correctly clipped to pipe. Replace flow thermistor. |
| Printed circuit board (PCB) replaced | Reset the boiler |
| No connection to primary printed circuit board (PCB) | Unblock pump |
| Pump rotor blocked | No connection to primary printed circuit board (PCB) |
| Flow temperature setpoint cannot be increased to 80ºC | Ensure flow temperature is not limited within installer mode |
| Pump runs during the night | Ensure system frost protection temperature setpoint isn’t set too high |
| Has the printed circuit board (PCB) just been replaced? | Reset the boiler |
| Are the boiler, central heating and hot water systems filled with water? Are all isolation valves and radiator valves open? | Fill and vent the system and open all isolation valves, then reset the boiler |
| Is the Flow/Return differential across the boiler in excess of 30c | Check the flow and return thermistors |
| Check that the pump is rotating freely. | Replace the pump, then reset the boiler |
| If the boiler is reset, does it ignite for a short time and then extinguish? | Check the detection electrode and associated harness for continuity, visual condition and position. Check if the condensate pipe is blocked. |
| Is the gas pressure avaliable at the boiler > 18mBar | Check gas supply and rectify fault |
| Is 215Vdc avaliable at the gas valve during ignition? | Check wiring from gas valve to printed circuit board (PCB) and replace if necessary, otherwise replace the main PCB |
| Unplug the gas valve – is the resistance between the pins between 1kW and 10kW? | Replace gas valve |
Vaillant Boiler Error Codes
| Fault Code | Possible Cause | Meaning |
|---|---|---|
| F.00 | NTC Faults | This means that your Flow NTC (Negative Temperature Coefficient Thermistor) cable is either defective or broken and needs to be replaced |
| F.01 | The Flow NTC (Negative Temperature Coefficient Thermistor) cable is either defective or broken and needs to be replaced | |
| F.10 | — | |
| F.11 | ||
| F.13 | — | |
| F.20 | Boiler has exceeded the maximum temperature and needs to cool down | |
| F.22 | Dry fire / Low water in system / Overheat | This means that there’s either no water in your system, you have a defective pump or the pump lead is defective |
| F.24 | Low water / Pump Failure / Blockage | Pump could be obstructed, running at low capacity, could be air trapped or the pressure might be too low. |
| F.28 | Either insufficient gas in the system, a defective electrode, ignition lead or electronic ignitor | |
| F.29 | Flame extinguished | Flame or pilot light has gone out – check flue duct or gas supply. |
| F.60 | Gas valve control defective | Cable loom (connects gas valve) might have short circuited, gas valve assembly defective or electronic control system issue. |
| F.61 | Gas valve control defective | Cable loom (connects gas valve) might have short circuited, gas valve assembly defective or electronic control system issue. |
| F.62 | Defective gas valve closure mechanism | Boiler has exceeded the maximum temperature and needs to cool down |
| F.63 | EEPROM (Electrically Erasable Programmable Read-Only Memory) error | Electronic fault. |
| F.64 | Electronic system or sensor fault | Flow or back flow NTC has short circuited, or an electronic fault |
| F.65 | Electronic system temperature too high | This can happen because of an external heat source or an electrical fault |
| F.67 | Electronic fault in the flame system | — |
| Fault Code | Possible Cause |
|---|---|
| F.1 | Lack of gas, a fault with the ignition or flue – may need to adjust the gas valve or replace a defective electrode lead. |
| F.4 | Ignition fault. |
| F.5 | The system has suffered a fault due to overheating. |
| F.6 | Your flow NTC has developed a fault. |
| F.17 | Check the polarity of your system. |
| F.24 | Pump-related faults – the pump could have failed, it may have over run or there could be an issue with the airlock |
| Fault Code | Possible Cause |
|---|---|
| F.00, .04, .05, .10, .14, .15 | All of these are NTC faults, and are best resolved by first changing all NTC to make diagnosis earlier. |
| F.21 | The pilot flame has failed. |
| F.22 | There is insufficient water in your system. |
| F.11 | A blockage in the appliance is preventing the system from flowing as it should. |
| F.12 | A blockage in the appliance is affecting the system’s pressure. |
| F.13 | The appliance is blocked because of a water deficiency. |
| Fault Code | Possible Cause |
|---|---|
| S.O | Heating issue, no heat demand |
| S.1 | Fan start-up error |
| S.2 | Pump flow error |
| S.3 | Heating mode error – ignition problem |
| S.4 | Heat mode – burner on error |
| S.6 | Heating mode – fan overrun error |
| S.7 | Heating mode – pump overrun error |
| S.8 | Heating remaining cut off for XX amount of time |
| S.31 | No heat demand summer operating mode |
| S.34 | Heating mode frost protection error |
| S.20 | Hot water requirement error |
| S.22 | Hot water handling pump flow error |
| S.24 | Hot water operation burner is on |
| S.85 | Service message quantity of circulation water |
| Fault Code | Possible Cause |
|---|---|
| F.00 / F.0 | Flow temperature sensor interruption |
| F.01 / F.1 | Return temperature sensor interruption |
| F.10 | Flow NTC short circuit |
| F.11 | Return NTC short circuit |
| F.20 | Safety switch off temperature limiter |
| F.22 | Safety switch off low water pressure |
| F.23 | Safety switch off temperature difference too great |
| F.24 | Safety switch off temperature is rising to fast |
| F.25 | Safety switch off flue gas temperature too high |
| F.26 | Error with gas valve – possible no function |
| F.27 | Safety switch off flame simulation |
| F.28 | Failure during start up – ignition unsuccessful to start |
| F.29 | Failure during operation – re-ignition unsuccessful |
| F.32 | Fan error |
| F.49 | eBUS error – possible short circuit |
| F.61 | Error with gas valve regulation |
| F.62 | Error with gas valve – switch off delay |
| F.63 | EEPROM error |
| F.64 | Electronics / NTC error |
| F.65 | Electronic temperature error could be overheating due to external influences |
| F.67 | Electronics flame signal error |
| F.68 | Unstable flame signal error air in gas |
| F.70 | Invalid device specific number (DSN) |
| F.71 | Flow NTC error – flow temperature sensor signal constant value |
| F.72 | Flow return NTC error – temperature difference too great |
| F.73 | Water pressure sensor signal in the wrong range, it is too low |
| F.74 | Water pressure sensor signal outside correct range, the sensor signal is too high |
| F.75 | Error with pressure – no pressure change detection when starting the pump |
| F.76 | Overheating protection on – primary heat exchanger has responded |
| F.77 | Flue non return flap condensate pump error |
| F.78 | Interruption to DHW outlet sensor at external controller |
| F.83 | Flow and or return temperature sensor error |
| F.84 | Error with flow/return temperature sensor temperature changing error |
| F.85 | Error with flow and return temperature, sensor incorrectly fitted |
| CONNECTION | No communication with the PCB |
| Fault Code | Possible Cause |
|---|---|
| S.00 | Heating mode error – no heat demand |
| S.01 | Heating mode fan start-up |
| S.02 | Heating mode error – water pump running |
| S.03 | Heating mode – ignition sequence error |
| S.04 | Heating mode – burner ignited |
| S.06 | Heating mode – fan overrun error |
| S.07 | Heating mode – pump overrun error |
| S.08 | Heating remaining cut off time xx minutes |
| S.10 | Hot water demand via impeller sensor |
| S.11 | DHW mode fan start up error |
| S13 | DHW mode ignition error |
| S.14 | Hot water demand via fan sensor error |
| S.15 | DHW mode pump and fan overrun |
| S.16 | DHW mode – fan overrun error |
| S.17 | DHW mode – pump overrun error |
| S.20 | DHW mode – burner on error |
| S.21 | DHW mode – fan start up error |
| S.22 | DHW demand – error pump running |
| S.23 | DHW ignition error |
| S.24 | DHW mode – burner error |
| S.25 | DHW mode – pump or fan overrun error |
| S.26 | DHW mode – fan overrun |
| S.27 | DHW mode – pump overrun |
| S.28 | Hot water burner anti-cycling time |
| S.30 | Room thermostat is blocking heating mode |
| S.31 | No heat demand boiler in summer operating mode |
| S.32 | Waiting period because of fan speed deviation |
| S.34 | Heating mode frost protection error |
| S.39 | Burner off contact has been triggered this could be because of contact thermostat or condensate pump |
| S.40 | Comfort safety mode active |
| S.41 | Water pressure > 2.8 bar |
| S.42 | Flue non return flap return signal blocks burner operation |
| S.46 | Comfort safety mode flame loss at minimum load |
| S.53 | Boiler is in waiting period of modulation f block function due to water shortage |
| S.54 | Boiler is in waiting period of operation, blocking function as a result |
| S.57 | Waiting period comfort safety mode |
| S.58 | Modulation limitation due to noise / wind error |
| S.61 | Gas family check unsuccessful |
| Fault Code | Possible Cause |
|---|---|
| S.20 | Warnstar demand |
| S.21 | Fan running |
| S.22 | Pump running |
| S.23 | Ignition sequence |
| S.24 | Burner ignited |
| S.25 | Fan and water pump running |
| S.26 | Fan overrun |
| S.27 | Pump overrun |
| S.28 | Anti-cycling mode |
| S.30 | No heating demand from external controls |
| S.31 | Central heating thermostat knob turned off |
| S.32 | Heat exchanger antifreeze active as fan speed variation is too high |
| S.34 | Anti-frost mode is active |
| S.36 | Not heating demand form low voltage |
| S.41 | Water pressure greater than 2.9 bar |
| S.42 | Response from accessory module or defective condensate pump is blocking burner operation |
| S.53 | Appliance is within the waiting period of the block operation function due to water shortage |
| S.54 | Appliance is within the waiting period of the block operation due to water shortage |
| S.96 | Return sensor error |
| S.98 | Flow return sensor check is running demand is block |
| D.0 | Heating part load error |
| D.1 | Water pump overrun – time for heat mode |
| D.2 | Max burner anti-cycling period at 20c flow temperature |
| D.3 | Hot water flow temperature reading |
| D.4 | Current temperature for warm stat sensor |
| D.7 | Warm start temperature target value |
| D.8 | External controls heat demand |
| D.9 | Flow target temperature from external analogue regulator terminal |
| D.10 | Status internal heating pump error |
| D,11 | Status external heating pump error |
| D.12 | Cylinder charging pump via accessory module |
| D.13 | Hot water circulation pump |
| D.22 | Hot water demand |
| D.23 | Summer/Winter function |
| D.25 | Hot water activation via ebus control |
| D.30 | Control signal for both gas valves |
| D.33 | Fan speed target value |
| D.34 | Fan speed actual value |
| D.36 | Hot water flow sensor |
| D.40 | Flow temperature target value |
| D.41 | Return temperature actual value |
| D.44 | Digitised ionisation potential error |
| D.47 | Outside temperature with weather compensator – Vaillant controller only |
| D.76 | Remaining burner anti-cycling time in min |
| D.90 | Digital regulator status |
| D.91 | DCF status with connected external probe |
| D.97 | Activation of the second diagnostic level |
| D.17 | Heating glow return regulation |
| D.18 | Pump mode return |
| D.19 | Operating modes of the two speed heating pump |
| D.20 | Maximum set value for target cylinder |
| D.27 | Switching accessory relay 1 |
| D.28 | Switching accessory relay 2 |
| D.50 | Offset for minimum speed |
| D.51 | Offset for maximum speed |
| D.58 | Activation of solar reheating |
| D.60 | Number of safety temperature cut off |
| D.61 | Number of unsuccessful lockouts |
| D.64 | Average ignition times |
| D.65 | Maximum ignition time |
| D.68 | Unsuccessful ignitions in the first attempt |
| D.69 | Unsuccessful ignition for the second time |
| D.70 | Set diverter valve position |
| D.71 | Maximum setting of heater control knob |
| D.72 | Pump overrun time after warm start |
| D.73 | Off set for warm start target value |
| D.75 | Maximum charging time for a storage without own controller |
| D.77 | Limitation of cylinder charging in output in kW |
| D.78 | Limitation of cylinder charging temperature in c |
| D.80 | Operating hours heating |
| D.81 | Operating hours hot water generation |
| D.82 | Burner start up in heating mode |
| D.83 | Burner start up in hot water mode |
| D.84 | Maintenance indicator – number of hours until the next maintenance |
| D.93 | DSN appliance variant setting |
| D.96 | Factory setting |
| Fault Code | Possible Cause |
|---|---|
| P.00 | The heating circuit and hot water circuit are purged |
| P.01 | Maximum load test program error |
| P.02 | Minimum load test program |
| P.06 | Filling mode test program |
| Fault Code | Possible Cause |
|---|---|
| D.0 | Heating part load error |
| D.1 | Water pump overrun – time for heat mode |
| D.2 | Max burner anti-cycling period at 20c flow temperature |
| D.3 | Hot water flow temperature reading |
| D.4 | Current temperature for warm stat sensor |
| D.5 | Set value of flow temperature or target value of return |
| D.7 | Warm start temperature target value |
| D.8 | External controls heat demand |
| D.9 | Flow target temperature from external analogue regulator terminal |
| D.10 | Status internal heating pump error |
| D,11 | Status external heating pump error |
| D.12 | Cylinder charging pump via accessory module |
| D.13 | Hot water circulation pump |
| D.15 | Pump speed actual value |
| D.22 | Hot water demand |
| D.23 | Summer/Winter function |
| D.24 | Not relevant |
| D.25 | Hot water activation via eBus control |
| D.30 | Control signal for both gas valves |
| D.33 | Fan speed target value |
| D.34 | Fan speed actual value |
| D.35 | Not relevant |
| D.40 | Flow temperature target value |
| D.41 | Return temperature actual value |
| D.44 | Digitised ionisation – potential error |
| D.47 | Outside temperature with weather compensator – Vaillant controller only |
| D.76 | Remaining burner anti-cycling time in min |
| D.90 | Digital regulator status |
| D.91 | DCF status with connected external probe |
| D.97 | Activation of the second diagnostic level |
| D.98 | Telephone a heating engineer |
| D.14 | Pump speed target value |
| D.17 | Heating flow return regulation |
| D.18 | Pump operating mode |
| D.20 | Maximum set value for target cylinder |
| D.26 | Additional relay control ecoTec |
| D.27 | Switching accessory relay 1 |
| D.28 | Switching accessory relay 2 |
| D.50 | Offset for minimum speed |
| D.51 | Offset for maximum speed |
| D.60 | Number of safety temperature cut offs |
| D.61 | Number of unsuccessful lockouts |
| D.64 | Average ignition times |
| D.65 | Maximum ignition time |
| D.67 | Remaining burner anti-cycling time |
| D.68 | Unsuccessful ignitions in the first attempt |
| D.69 | Unsuccessful ignition for the second time |
| D.70 | Set diverter valve position |
| D.71 | Maximum setting of heater control knob |
| D.72 | Pump overrun time after warm start |
| D.75 | Maximum charging time for a storage without own controller |
| D.77 | Limitation of cylinder charging in output in kW |
| D.78 | Limitation of cylinder charging temperature in celsius |
| D.80 | Operating hours heating |
| D.81 | Operating hours hot water generation |
| D.82 | Burner start up in heating mode |
| D.83 | Burner start up in hot water mode |
| D.84 | Maintenance indicator – number of hours until the next maintenance |
| D.93 | DSN appliance variant setting |
| D.96 | Factory setting |
Worcester Boiler Error Codes
| Fault Description | System Behaviour |
|---|---|
| 226 | Service tool has been connected in the blocking error history menu |
| FD 231 | The power has been interrupted during a lockout |
| C7 214 | Fan does not run during the start up phase – fan harness connector needs checking |
| C6 215 | Fan speed too high – check the fan harness and connector |
| C7 216 | Fan speed too low – check the fan harness and connector |
| C7 217 | Fan has stopped during appliance operation |
| C1 264 | Fan stopped during operation |
| C4 273 | Continuous fan operation for the last 24 hours – appliance temporarily blocked |
| E2 222 | Flow temperature sensor shorted |
| E2 233 | Flow temperature sensor disconnected |
| E9 276 | Primary flow temperature exceeded 95°c |
| E2 350 | Flow temperature sensor shorted |
| E2 351 | Flow temperature sensor disconnected |
| FA 306 | Ionisation detected after the gas valve closed |
| EA 227 | No ionisation detected after ignition |
| F7 228 | Isioniation current detected before burner start |
| EA 229 | Loss of ionisation signal during operation |
| EA 261 | Heat control module (HCM) potentially defective – reset the appliance |
| 9U 233 | Control box or heat control module (HCM) is defective or loose, the HCM needs to be checked |
| C4 237 | Control box or heat control module (HCM) is defective |
| F0 238 | Gas valve or control box error – gas valve coils need checking |
| F0 239 | Control box or the heat control module (HCM) is defective – the control box connections need checking |
| F0 242 | Control box or the heat control module (HCM) is defective – the HCM and control box connections need to be checked |
| B7 257 | Control box or the heat control module HCM) is defective- the HCM and control box connections need to be checked |
| F0 258 | Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked |
| EH 258 | Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked |
| F1 259 | Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked |
| F0 262 | Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked |
| F1 263 | Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked |
| F0 272 | Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing |
| F0 280 | Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing |
| F0 290 | Control box is defective – HCM needs checking as it might not be inserted properly or need replacing |
| 328 | Internal error with the mains voltage – frequency may be inconsistent |
| 235 | Incompatible heat control module (HCM) software versions – control box needs latest software |
| 356 | Low mains voltage – the voltage may be interrupted or inconsistent and needs checking |
| 360 | Heat control module (HCM) invalid – the inserted HCM does not correspond with the control box |
| A8 362 | Low mains voltage – the voltage may be interrupted, inconsistent or heat control module (HCM) invalid |
| CC 800 | Outdoor sensor defect available when accessory outdoor sensor is connected |
| A1 281 | Pump stock or running dry |
| E9 224 | Flue or high limit thermostat activated |
| D4 341 | Primary flow temperature rising too fast |
| Fault Description | System Behaviour |
|---|---|
| 208 | The boiler is in chimney sweep mode |
| 200 | The boiler is in heating mode |
| 201 | The boiler is in domestic hot water (DHW) mode |
| 202 | The boiler is waiting – there was a heat demand from the on off or modulating control |
| 203 | The boiler is on standby |
| 204 | The boiler is waiting – the actual temperature is higher than the calculated or selected boiler temperature |
| 212 | The temperature recorded by the flow temperature sensor or the safety sensor is rising too quickly |
| 226 | Diagnosis tool was connected and is now locked out |
| 260 | The flow temperature sensor is not detecting a rise in temperature following a burner start |
| 265 | The boiler is waiting in response to a heat demand – the boiler regularly switches to partial load |
| 268 | Component test phase |
| 270 | The boiler is modulating upwards |
| 283 | The boiler is preparing for a burner start – the fan and pump are activated |
| 284 | The gas valve is switched |
| 305 | The boiler is waiting for domestic hot water (DHW) operation to end |
| 235 | The KIM (boiler identification module) is too new for the burner control unit |
| 360 | The KIM that has been fitted is not compatible with the burner control unit |
| 9A 361 | The burner control unit that has been fitted is not compatible with the KIM (boiler identification module) |
| 9U 233 | The burner control unit or KIM (boiler identification module) is faulty |
| A3 317 | Short circuit in the flue gas temperature sensor contacts |
| B7 257 | The burner control unit or the KIM (boiler identification module) is faulty |
| C1 264 | No control signal or power supply to the fan during operation |
| C4 273 | The boiler was switched off for a maximum of 2 minutes because it had been operating continuously for more than 24 hours |
| C6 215 | The fan speed is too high |
| C6 216 | The fan speed is too low |
| C7 214 | The fan does not run during the start phase |
| C7 217 | The fan speed is irregular when starting up |
| CE 207 | Water pressure is too low |
| CE 266 | Pump test failed |
| D1 240 | The contacts of the boiler return temperature sensor have been short circuited |
| D1 241 | The contacts of the boiler return temperature sensor have been interrupted |
| D3 232 | The external switching contact has opened |
| D4 213 | The actual temperature recorded by the flow temperature sensor or return temperature sensor is rising too quickly |
| D4 271 | Actual temperature differential between flow and safety temperature sensor is too high |
| D4 286 | The boiler return temperature sensor has detected a return temperature higher than 105°c |
| E2 222 | Short circuit in the flow temperature sensor contacts |
| E2 223 | The flow temperature sensor contacts have been interrupted |
| E5 218 | The temperature captured by the flow temperature sensor exceeded 105°c |
| E9 210 | The temperature measured by the flue gas sensor is too high and is open |
| E9 219 | The safety temperature sensor has captured a temperature in excess of 105°C |
| E9 220 | The contacts for the safety temperature sensor have shorted or the safety temperature sensor has detected a temperature higher than 130°c |
| E9 224 | The contacts of the safety temperature sensor have been interrupted |
| E9 276 | The temperature flow sensor has measured a temperature in excess of 95°c |
| E9 277 | The safety temperature sensor has measured temperature in excess of 95°c |
| E9 285 | The boiler return temperature sensor has measured a temperature higher than 95°c |
| E9 318 | The flue gas temperature sensor contacts have been interrupted |
| EA 227 | An insufficient ionisation current was measured following ignition of the burner |
| EA 229 | The ionisation current detected by the system during the burning phase was insufficient |
| EA 234 | The contacts of the gas valve have been interrupted |
| EA 261 | The burner control unit is faulty |
| EA 269 | The ignition device has been activated for too long |
| F0 238 | The burner control unit KIM (boiler identification module) is faulty |
| F0 239 | The burner control unit KIM (boiler identification module) has an error. Cabling might have poor contact breaks and pinching or the plug and wiring of the burner control unit needs checking, also check the operating characteristics of the boiler by replacing the burner control unit. |
| F0 242, F0 243. F0 244. F0 245, F0 246. F0 247, F0 248, F0 249, F0 250, F0 251, F0 252, F0 253, F0 255, F0 259, F0 263, F0 267, F0 272 | The burner control unit (KIM) is faulty – the wiring of the burner control unit needs checking, also check the operating characteristics of the boiler by replacing the burner control unit. |
| F0 278 | The sensor test has failed – cabling and plug sensors need checking |
| F0 279 | The burner control unit, or KIM, is faulty – control unit may need replacing |
| F0 280 | The burner control unit is faulty |
| F0 287 | The burner control unit, or KIM, has an error |
| F0 290 | The burner control unit, or KIM, is faulty |
| F7 228 | An ionisation current was measured before the burner started |
| F7 328 | A brief power failure has occurred |
| FA 306 | An ionisation current was measured after the burner went out |
| FD 231 | The mains voltage was interrupted during an interlocking fault |
| EC 256 | The burner control unit has an error |
| EH 258 | The burner control unit is faulty – check the plug and wiring of the burner control unit. |
| H07 | The current water pressure is too low, limiting the performance in heat mode as well as domestic hot water (DHW) mode |
| HrE | The boiler keeps resetting |
| rE | The boiler resets |
| Fault Description | System Behaviour |
|---|---|
| Light off | No boiler demand |
| Light on | Heating demand on boiler is OK |
| 1 flash 5 seconds off | No ionisation detected after ignition |
| 2 flashes 5 seconds off | Loss of ionisation signal during operation |
| 3 flashes 5 seconds off | Gas valve error |
| 4 flashes 5 seconds off | First safety timing error / ignition timing error |
| 5 flashes 5 seconds off | Ionisation detected after burner stopped Gas valve EV2 leak test failed Gas valve EV1 leak test failed Ionisation current detected before burner start Gas valve error Ionisation sensor shorted |
| 4 flashes 5 second gap 1 long flash | Sensor test failed |
| 4 flashes, 5 second gap, 2 long flashes | Safety temperature too high |
| 4 flashes, 5 second gap, 3 long flashes | Max safety thermostat activated |
| 4 flashes, 5 second gap, 4 long flashes | Return temperature too high |
| 4 flashes, 5 second gap, 5 long flashes | Flow temperature too high – supply sensor exceeded 110°c |
| 1 long flash, 4 quick flashes, 5 second gap, 1 long flash, 4 quick flashes | Heating control module (HCM) defective |
| 2 long flashes, 4 quick flashes, 5 second gap, 2 long flashes, 4 quick flashes | Fan running too fast Fan running too slow No airflow after defined period of time Fan not running |
| 3 long flashes, 4 quick flashes, 5 second gap, 3 long flashes, 4 quick flashes | Mains voltage interrupted after locking error |
| 4 long flashes, 4 quick flashes, 5 second gap, 4 long flash, 4 quick flashes | Internal control board faults |
| 5 long flashes, 4 quick flashes, 5 second gap, 5 long flash, 4 quick flashes | All other miscellaneous faults – reset the boiler by turning the control knob anti-clockwise to the reset position |
| Fault Description | System Behaviour |
|---|---|
| No light | No power at control board |
| Light on | Appliance on but not operating during demand |
| Slow flash ( mostly off flashes on) | Ignition lockout |
| Slow flash ( mostly on flashes off) | Flue overheat or heat exchanger overheat |
| Fast flash | Volatile lockout sensor fan or code plug |
| 2 pulses | Check service mode switch is in minimum position |
| 5 pulses | Check service mode switch is in max position |
| Fault Description | System Behaviour |
|---|---|
| 200 O | Boiler in heating mode |
| 201 O | Boiler in hot water mode |
| 202 O | Boiler in anti-cycle mode |
| 203 0 | Boiler in standby – no heat energy demand |
| 204 O | Current primary water temperature higher than set value |
| 208 0 | Chimney sweep demand |
| 224 V | Safety temperature limiter has tripped – top-up water until the reset pressure is reached |
| 227 V | No flame signal after ignition burner control unit could need replacing |
| 228 V | Flame signal without flame present – air/gas ratio control valve may need replacing as might the ionisation cable |
| 305 0 | Boiler in hot water anti-cycle mode |
| 306 V | Flame signal after closing the fuel supply – the air/gas ratio control valve might need replacing |
| 360 V | Incompatible code plug – check if a correct code plug is installed and exchange or reconnect code plug |
| 815 W/B | Low loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage |
| 1010 O | No BUS communication cable, EMS-Bus isn’t connected or damaged – connect the cable for the EMS-Bus or replace the damaged cable exchange fuse |
| 1017 W | Water pressure too low – the water needs topping up and the vent system or pressure sensor may need replacing |
| 1021 B | Hot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected |
| 1022 B | Hot water storage temperature sensor is defective – connect the plug to the hot water temperature sensor correctly, mount the hot water temperature sensor correctly or replace the hot water temperature sensor |
| 1037 W | Outside temperature sensor is defective – check the connecting lead |
| 1065 B | Pressure sensor defective or not connected – check pressure sensor connection as it may need replacing |
| 1068 W | Outside temperature sensor defective – check the connecting lead |
| 1073 W | Short circuit of the flow temperature sensor – the temperature sensor may need replacing |
| 1074 W | No signal from the flow temperature sensor available – connect the plug to the flow temperature sensor correctly or temperature sensor could need replacing |
| 1075 W | Short circuit of the temperature sensor at the heating block – temperature sensor may need replacing |
| 1076 W | No signal from the temperature sensor at the heating block available – replace the temperature sensor, the connecting lead or the control unit |
| 2920 V | Error with the flame monitoring |
| 2924 V | No feedback from the modulating gas valve. The gas valve relay is defective – press the reset button and apply burner start, wait to see if fault reoccurs, if it does the gas valve needs replacing |
| 2925 V | Feedback from the modulating gas valve is too low |
| 2927 B | Flame failed during burner operation. Open the main shut off valve, shut down the appliance and check gas line, replace the ionisation electrode, set burner correctly and minimum rated load, check the integrity flue system and if the interconnected room air supply is too small, or the size of the ventilation opening is too small, clean the heating block on the flue gas side or replace the control unit/burner control unit |
| 2946 V | Incorrect code plug detected – the code plug needs replacing |
| 2948 B | No flame signal. With low output the burner starts automatically after cleaning. If the fault occurs repeatedly, the setting of the CO2 valves need checking |
| 2950 B | No flame signal. Following starting procedure the burner starts automatically. After cleaning set the correct gas / air ratio correctly |
| 2963 B | Signal from flow and heat exchanger temperature sensor outside the permissible range – the connecting lead needs connecting correctly |
| 2964 B | Flow rate in heat exchanger is too low |
| 2965 B | Flow temperature too high |
| 2966 B | Flow temperature rise in heat exchanger too rapid |
| 2967 B | Flow / heat exchanger temperature sensor differential too great |
| 2970 B | Pressure drop in heating system too rapid |
| 2971 B | System pressure too low – the heating system needs venting or water needs topping up until the preset pressure is reached. Replace the cable to the pressure sensor replace the pressure sensor |
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