Volkera Easi-Flo water heater

[Microman9]

The heater is 3 years old, LPG and serviced each year.

The heater will ignite, go out, ignite. Perhaps do this 4 or 5 times.
Sometimes it would stay in and give hot water.
Other times it would not stay in at all.

When the air box cover is removed, it ignites right away and works perfectly every time.

Put the cover back on and the same fault returns.
The air pressure switch is okay and the fan always runs.
Both silicone tubes were removed and cleaned.
Flue is clear
Gas inlet pressure checked.

Yesterday the Gas engineer said the gas valve needs replaced, but the heater works perfectly when the air box cover is removed.

Any suggestions what might be wrong.

 

[CBW]

Sounds like a lack of oxygen, so it could be the flue/fan/aps etc. Should be in plumbing/heating really, there’s a good knowledge of these boilers on this forum, wouldn’t want you to miss out

 

[Microman9]

Thank you Chris for your prompt response.
I will go to that forum.