Vaillant Boiler F.62 Error Code

Flame took too long to go out on Vaillant boilers.

F.62

May need a pro

When the boiler shut the burner down, the flame signal faded later than it should. Vaillant blames a leaking or slow gas valve, the ignition electrode or the PCB.

Compatible models

Both Vaillant's UK fault list and the ecoTEC plus VU ..6/6-5 OVZ manual include F.62; neither gives a model list.

Also shown as

No other codes are listed for this fault.

Difficulty

Try the basic checks, but the usual fix is a technician's job.

How to fix
When to call a pro
Parts
FAQ

Not sure you are reading the code right? See how to read Vaillant boiler codes.

Safety first: never take the casing off a gas boiler. If you smell gas, open windows, don't use light switches, turn the gas off at the meter if you can and call your gas emergency number from outside. A carbon monoxide alarm going off means the same: switch the boiler off, get fresh air and call.

How to fix Vaillant F.62

Switch the boiler off
Turn it off and close the gas stopcock under the boiler if you can do so safely. Don't keep resetting.

When to call a technician

A gas valve that may not be shutting off cleanly needs a Gas Safe engineer soon. If there's any smell of gas, get out first and ring the emergency number from outside.

Parts linked to F.62

These are the parts an engineer usually checks for this code. They sit inside the sealed casing, so leave them to a Gas Safe registered engineer.

Frequently asked questions

Which Vaillant models show the F.62 code?

Both Vaillant's UK fault list and the ecoTEC plus VU ..6/6-5 OVZ manual include F.62; neither gives a model list.

Can I fix Vaillant F.62 myself?

Only the outside checks. The steps above are the ones Vaillant's user instructions allow; if they don't clear F.62, the fix is inside the boiler and needs a Gas Safe registered engineer (RGII in Ireland).

Other Vaillant boiler codes

Last reviewed 2026-10-21. Codes and steps can vary by model; check your owner's manual.

Sources we checked