What Is a Vaillant F61 Fault Code ?

What Is a Vaillant F61 Fault Code ?

The F61 error code on a Vaillant boiler indicates a fault with the gas valve or the PCB (Printed Circuit Board)

What Does the F61 error code on a Vaillant Combi boiler Mean?

The F61 fault code on a Vaillant boiler indicates that the boiler’s gas valve has developed a fault and/or that the PCB (the boiler’s ‘brain’) is not receiving or processing signals correctly.

If the boiler is unable to regulate gas flow properly, or it can’t communicate with the component responsible for doing so, your boiler will lock out and display F61 to prevent any risk of gas-related issues.

 Common Causes of the F61 Error

• Faulty gas valve: The valve may be stuck, jammed, or failing to open/close as it should.  A new gas valve is required as this cannot be repaired
• Faulty PCB: The control board itself may be malfunctioning and unable to process signals properly.
• Wiring issue: Loose, damaged, or corroded wiring between the gas valve and PCB.
• Previous water damage or corrosion: The PCB on Vaillant boilers are particularly sensitive and any water which may have made contact with the PCB, will have damaged it irreparably.  A new PCB will be required

 Can I Fix the F61 Fault Myself?

No — and you shouldn’t try to.
The gas valve or PCB are critical components, and any issue involving gas and boilers should only be handled by a Gas Safe registered engineer. Attempting to fix it yourself is not only dangerous but can also void your boiler warranty.

 How Is the F61 Fault Fixed?

A qualified engineer will:

1. Check the gas valve for signs of failure or restriction and replace the gas valve
2. Test the wiring and connections between the gas valve and PCB.
3. Run diagnostic tests after installation of the gas valve or other components to determine if the PCB is indeed at fault and replace it. As the PCB is one of the most expensive parts in a boiler, this would be the last part to be replaced and not the first line of approach.
4. Calibrate and test the gas valve and PCB after installation

In some cases, both components may need replacing

 Can the Boiler Be Reset?

You can attempt to reset your boiler via the control panel — but if the fault returns and the issue has not been resolved, you will need professional attention. Repeated resets won’t fix the underlying problem.

Need Help with a Vaillant F61 Error?

At Boilergurus, we are experienced in diagnosing and repairing Vaillant boiler faults, including the F61fault. If you are seeing this error, get in touch with our team and we will get you safely back up and running.

  Call us or message us on WhatsApp: 0207 101 4370
  Or email: info@boilergurus.com

Safety first. Always call a Gas Safe engineer when dealing with gas-related boiler faults.