Strange Prima problem, UPDATED

[ianrp]

Hi all,
I hope you can help me with this. I have spent two hours with a CORGI this evening trying to work out what the problem is, but we haven't been able to. Boiler is a Potterton Prima 60F.

Its like this -

Call for heat
Fan starts (maybe not as loud as before, but that might be my hearing)
No further noise or action.

Manually sucking on pressure switch or bypassing it with a changeover switch at the right time will get the pilot light to ignite. Ignition sparks continue but main burner remains unlit. We have checked the pipes to the pressure switch and ensured the restrictor is clear.

Searching here hasn't revealed a solution, because it doesn't seem like a faulty pressure switch, more like lack of fan pressure, but overcoming that doesn't get the boiler lit. I have a wife off work recovering from a back problem and really suffering from the cold, so any help would be really gratefully received.

Thanks

 

[Agile]

Get a new CORGI !

Any competent CORGI will have measured the pressure from the venturi to determine if its the APS or the venturi.

I dont remember if it will even work with cover off!

You dont say if the pilot lights ???

If not then he should have checked gas valve first stage to see if its powered and if so opening.

If it lights then the flame is not been detected if it keeps on sparking.

OK you may have two faults but any competent CORGI would know how to investigate each one to determine whats wrong. These kind of things are so simple. This is what we do every day !!!

Tony

 

[ianrp]

Thanks Tony.

Yeah, he wasn't the most inspiring guy.

The pilot lights if pressure is applied to the pressure switch manually or it is bypassed with a changeover switch, but it keeps sparking and the main jets don't light.

The problem started with the fan cycling on start up but it would eventually light up and be fine.

 

[baxpoti]

PCB needs replacing

 

[ianrp]

PCB needs replacing

Thanks baxpoti.

Would that cover all the problems?

 

[baxpoti]

The problem started with the fan cycling on start up but it would eventually light up and be fine.

Classic symptom

 

[ianrp]

The problem started with the fan cycling on start up but it would eventually light up and be fine.

Classic symptom

Ta!

 

[ianrp]

Changed the pcb but unfortunately it hasn't fixed the problem. Bypassing the pressure switch with a changeover switch gets the boiler to fire, but it then immediately cut offs again.

I don't want to use the same CORGI guy (see above) again, so any suggestions as to what to check next?

Thanks.

 

[Soggy_weetabix]

PCB needs replacing

Of course it does. Its a Potterton over 12 months old.

Budget for another PCB a year or 2 down the line...and another one after that.

David
[/quote]

 

[ianrp]

PCB needs replacing

Of course it does. Its a Potterton over 12 months old.

Budget for another PCB a year or 2 down the line...and another one after that.

David

[/quote]

Changing this one didn't solve the problem, though. Any other thoughts?

 

[Baxmax]

Hows your wifes back,i had a back problem a couple of months ago,i was told i have to strengthen my stomache muscles.I hope you find this helpfull.

 

[baxpoti]

Back to basics, I trust you are fitting the combustion box door, correcttly, when testing the appliance, as it won't fire with the door off and also things like the air tubes are not split, the fan/boiler voltage is correct etc

 

[ianrp]

Hows your wifes back,i had a back problem a couple of months ago,i was told i have to strengthen my stomache muscles.I hope you find this helpfull.

Thanks, Baxmax. She had an operation three years ago but has never properly recovered. She has done a lot of strengthening exercises, gym, pilates, etc which has helped, but she still has really bad spells.

 

[Agile]

Repeat of what I said earlier as its still relevant:-


I dont remember if it will even work with cover off!

You dont say if the pilot lights ???

If not then he should have checked gas valve first stage to see if its powered and if so opening.

If it lights then the flame has not been detected if it keeps on sparking.

Tony

 

[ianrp]

Back to basics, I trust you are fitting the combustion box door, correcttly, when testing the appliance, as it won't fire with the door off and also things like the air tubes are not split, the fan/boiler voltage is correct etc

We did generally check the voltages, air tubes and door last night. I'm not a CORGI so I'm not going to fiddle with those myself.