Vaillant F62 Fault Code Repair

This page contains the information required to help repair and diagnose the fault codes being shown on the boiler display. The following information, will take you through the fault finding sequence or steps, for rectifying a Vaillant Ecotec boiler with this fault code. Suggested solutions will be detailed further down the page.

Models applicable to:

Ecotec Plus, Ecotec Exclusive, Ecotec Pro

F.62 Meaning:

Gas valve switch-off delay


Delayed shutdown of gas valve detected– Secondary light (ignition and monitoring electrode indicates delayed extinguishing of the flame signal)
– 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. Carry out local tightness test on the gas valve. If gas tight then then likely you may have to replace the PCB
  2. Replace the gas valve


This fault commonly occurs alongside fault code F.61

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.