
Vaillant F61 fault code
- Written by Tamer Izzet
- fault codes, Vaillant Boilers
Vaillant F61 fault code

Vaillant F61 Fault Code: Causes and Solutions
The Vaillant F61 fault code indicates a malfunction within the boiler’s gas valve system, which is crucial for regulating gas flow to the burner. This issue can lead to a complete shutdown of the boiler, resulting in a loss of heating and hot water. Addressing this fault promptly is essential for maintaining the safety and efficiency of your heating system.
Understanding the Vaillant F61 Fault Code
When a Vaillant boiler displays the F61 error code, it signifies a problem with the gas valve, the wiring harness, or the printed circuit board (PCB). The gas valve controls the flow of gas to the burner, and the PCB manages this process by receiving information from various sensors within the boiler. A fault in any of these components can trigger the F61 error, causing the boiler to lock out as a safety precaution.
Common Causes of the Vaillant F61 Fault Code
Several factors can lead to the Vaillant F61 fault code:
Faulty Gas Valve: Over time, the gas valve may become stuck or seized due to wear and tear, preventing it from operating correctly.
Wiring Issues: Loose or damaged wiring between the gas valve and the PCB can disrupt communication, leading to the F61 error.
PCB Malfunction: A defective PCB can fail to send or receive signals properly, causing the gas valve to malfunction.
Cause | Description | Recommended Action |
---|---|---|
Faulty Gas Valve | The gas valve is stuck or seized, preventing proper gas flow to the burner. | Consult a Gas Safe registered engineer to inspect and replace the gas valve if necessary. |
Wiring Issues | Loose or damaged wiring between the gas valve and PCB is disrupting communication. | A qualified engineer should repair or replace the faulty wiring to restore proper function. |
PCB Malfunction | The printed circuit board is defective, causing miscommunication with the gas valve. | Have the PCB tested and replaced by a professional if found to be faulty. |
Diagnosing and Fixing the F61 Fault Code
Due to the potential dangers associated with gas appliances, it’s imperative to consult a Gas Safe registered engineer to diagnose and repair the F61 fault. The typical steps involved include:
Inspection: The engineer will examine the gas valve, wiring harness, and PCB for signs of damage or wear.
Testing: They will test the gas valve to determine if it’s operating correctly and check the wiring for continuity issues.
Replacement: If any component is found to be faulty, the engineer will replace it to restore the boiler’s functionality.
Attempting to reset the boiler without addressing the underlying issue may provide temporary relief, but the fault is likely to recur. Professional intervention ensures a thorough and safe resolution.

Preventative Measures
To minimize the risk of encountering the F61 fault code:
Regular Maintenance: Schedule annual boiler services with a qualified engineer to ensure all components are functioning correctly.
Prompt Repairs: Address any boiler issues immediately to prevent them from escalating into more significant problems.
System Checks: Regularly inspect your heating system for signs of wear or damage and report any concerns to a professional.
Additional Considerations
For homeowners experiencing frequent boiler issues, seeking expert advice from the Master Gas team is advisable.
Regular boiler servicing can help identify and address smaller problems early, reducing the likelihood of costly boiler repair work in the future.
Additionally, enrolling in a boiler cover home care plan can lower your expenses on aging boilers, providing annual servicing and repairs at a more affordable price.
Related Vaillant Fault Codes
For more information on other Vaillant fault codes, you can refer to the following:
Relevant Services
Consider exploring the following services to maintain and enhance your heating system:
Relevant Articles
For more information on Vaillant Boilers you can refer to the following articles:
Popular Services
What Our Customers Say

Darrell Horwood
08/01/24
Tam and his team, great price, great installation , clean tidy, great after care. Most of all Nice people. Vaillant Ecotec Plus. Rad installed.In the words of Tina Turner “simply the best”

Rachel Cranshaw
05/01/24
Installed a new boiler for us in 2022. New Year’s Eve 2023 we had an unrelated problem with our Co2 alarm, Ed called me, then came round to check everything was fine – fantastic service and we were so grateful!

Darryl Gould
12/11/23
We had a boiler replaced. The team were amazing from quotation to installation. The new boiler was installed in a day. The house was left tidier than when they arrived. Highly recommended.

Terry H
03/01/24

Leo Adewebi
19/10/23
Referred to this amazing company Master Gas London as l needed to replace an old boiler. I contacted them, in a couple of days, surveyed, detailed quote with recommendations, and installation arranged.

Paul S
21/12/23
New boiler, replacement of leaking underfloor heating manifold, rerouting overflow pipe, improved piping in cellar – all completed to a high standard in one day. Thanks!

Ben Ross
18/11/23
Highly recommend Master Gas for any boiler issues. They came and fitted a new boiler quickly and at a fair price & were a pleasure to have in the house. Highly recommend.