Vokera Compact 29HE fault

[tommyad123]

Hi I went to look at a vokera compact for a mate that is locking out to a solid red light. On start up either Heating or Hot water mode the boiler will start up as usual and as expected. But soon after start up the burner seem to modulate down low, it will continue to run like this for a few minutes. After a few minutes the burn extinguishes, but tries to relight straight after. The boiler can be heard sparking, but fails to light. After this the boiler locks out with a solid red light.

I have fitted a new primary temp sensor which hasn't worked. Im told the has also recently had a new fan pressure switch. I have spoke to vokera and they reckon its the gas valve.

Has anybody got any ideas? or has anybody had the same problem

Thanks for your help!!

 

[Blake]

Welcome to the forum. If you spoke to Vokera I assume they asked you to carry out some tests using a multimeter? Checking for voltage at gas valve etc. What makes you question there advice on the gas valve?

 

[mountainman]

Welcome to the forum. If you spoke to Vokera I assume they asked you to carry out some tests using a multimeter? Checking for voltage at gas valve etc. What makes you question there advice on the gas valve?

Because it's much more expensive than a sensor I suspect.

 

[tommyad123]

I don't think there would be a problem with the gas valve cos the boiler is starting up ok from cold, it's only after a few minutes of running the problem occurs. I was expecting vokera to tell me the PCB is the problem. But now they've told me its the gas valve I don't know what to think now.

 

[CES]

Gas valves can be ok when cold but after a while the coil in the gas valve heats up, expands and breaks the circuit, hence the gas valve drops out and wont start up again until the coil cools and contracts, making the circuit again.... (and breathe...)

 

[tommyad123]

Thanks CES I'll check this out. I'll get the multimeter out.