Boiler not firing

[dewaltdave1]

I have a Potterton Prima F 50 boiler.

I have just changed out the air pressure switch as the boiler wouldnt fire. Turns out the switch for some reason was full of water. Multimeter on the switch showed that it did work, but the fact that it was full of water prevented it from working.

All replaced, turned the boiler on and I am presented with the same fault.

Fan comes to life straight away, but the gas valve and ignition sequence doesn't start up.

Flue is clear of obstructions.

If I draw on the hoses to the APS I can get the boiler to light - so (I think I am fairly safe to assume) that the gas valve and PCB are good.

In one of the APS hoses is a small brass restrictor with a tiny hole through it which appears clear.

Would I be right to lean towards the fan being at fault as it isnt creating the air flow to pull the APS into position?

It was replaced from the original one about a year ago for a non branded replacement. The fan still works and if I put my hand over the flue outside there is quite the flow of air being pushed out.

An intermediary (sp?) flue was fitted last year too and still appears to be in good condition.

Any help would be appreciated before I get an engineer in. I dont know any local friendly ones and I dont want to be taken for a long walk!

Thanks in advance!

 

[picasso]

You have got more chance of a bj off her maj than you have of getting any help with your post, get someone in that knows what they are doing, what exactly is an "intermediary (sp)" flue ?

 

[Stadan20]

Bare in mind u have to be gsr to even take off that main door, don't be a penny pincher and get some one that's qualified out

 

[dewaltdave1]

Im pretty sure it was called an intermediary flue. It was a repair kit the nPower/Homeserve bloke fitted. No need to go and find the invoice for it, but it was to correct a corroded flue.
<<Quick google>> it was a Remedial Flue Kit! Intermediary ???
Main door hasn't been removed. The APS is not within the main door.
Thanks for your help though.

 

[picasso]

The aps is one of the safety critical parts of your boiler, the forum rules dont allow anyone to post advice about gas which the APS comes under, try and get a recommendation from neighbours/family ect for an engineer before you throw any more money at your boiler.

 

[dewaltdave1]

I appreciate the explanation Picasso,
Thanks.

 

[Agile]

The cover which you have removed to access the APS is sealed to provide the room sealed design of the boiler which separates the products of combustion from the room and enables the boiler to operate safely.

This forum has a duty of care to users and so we can not give advice on gas/safety/combustion issues as these are properly addressed by a qualified gas registered engineer on site.

Tony

 

[TCCHeating]

The cover which you have removed to access the APS is sealed to provide the room sealed design of the boiler which separates the products of combustion from the room and enables the boiler to operate safely.

This forum has a duty of care to users and so we can not give advice on gas/safety/combustion issues as these are properly addressed by a qualified gas registered engineer on site.

Tony

Sorry tony. Not quite right. The aps on these is located at the bottom. Outside of the combustion chamber.

But nonetheless completely agree. Op should not be messing about with any safety device. Even if it is located outside of the combustion chamber.