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Vaillant F61 Fault Code Repair

Welcome to the fault-codes section of this site. The following table or page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. You may be guided through the fault finding sequence or steps, for rectifying your boiler with this fault code. Suggested repair solutions may be provided by a link to a repair page. NB Some fault codes are only applicable to a specific range of boilers only.

Models applicable to:


F.61 Meaning:

Gas valve actuation fault


The gas valve cannot be actuated

  •  Cable harness supply line to the gas valve is defective (short to earth, short circuit)
  •  Gas valve defective
  •   PCB defective

Statistical chances of faults

There is a ~82% chance of the PCB being at fault
There is a ~4% chance of the Gas Valve being at fault
There is a ~14% chance of something else causing the fault.


  1. Check the resistance across the gas valve for 50-54 ohms(+/-10%). If this correct, then likely the PCB needs to be replaced.
  2. If the gas valve fails resistance test, then likely the gas valve needs to be replaced.


This fault commonly appears alongside fault F.62

Disclaimer: Information on this website is provided for informational purpose therefore we cannot accept liability for subsequent problems. All repair tasks should be carried out by qualified trades people. We may also receive commission payments when you are taken to external websites and complete purchases from third party sellers, once you leave our site, we cannot be held liable for your purchases.