potterton profile 80e problem

[dexion7]

hi,

i've searched and cant find a similar problem to mine so hope someone can shed some light.

the fan runs as normal and after the typical amount of time (about 10 seconds) the gas valve opens but there is no ignition. i know the gas valve opens as the boiler is close to the gas meter.

looking through the window i can't see any spark but gas continues to flow. there is a regular 'click' about every 5 seconds which, when the boiler was previously working correctly, would signal ignition. any ideas and should gas continue to flow even in the absence of ignition?

thanks

 

[Agile]

The fault seems to be a lack of ignition spark.

Unless you have been fiddling with the boiler and just knocked off the ignition lead from the back of the PCB then I dont see that its going to be a DIY repair.

Tony

 

[dexion7]

thanks for your reply but is it normal for gas to continue to flow?

 

[Agile]

The PCB is designed with a built in sequence for ignition.

The spark starts and a second later toe gas valve is opened. If a flame is not detected within about 3-5 seconds then the gas is shut off.

If the gas stays on much longer then there is a fault and a potentially dangerous one which will need a professional to rectify.

Tony

 

[dexion7]

presumably both the gas valve and the spark are controlled by the pcb so is it likley that this is the cause of the problem?

 

[monoxide62]

hi,


the fan runs as normal and after the typical amount of time (about 10 seconds) the gas valve opens but there is no ignition. i know the gas valve opens as the boiler is close to the gas meter.

Maybe you are seeing dials moving when they are obviously stationary............main gas valve will not open unless pilot flame has been detected so baffled you see meter dial moving , if you were to post the correct information then i suspect you will get an informed answer.

 

[dexion7]

it is the correct information! the gas meter is not lying you pillock - the meter needle moves around showing gas is flowing through the meter and the burner does not light

 

[gasafengineer]

Can also see a pink pig flying past my window.

 

[Agile]

Well if the gas valve is opening and there is no spark or flame then there might be a serious fault.

In that case a gas registered engineer should be called.

Tony

 

[monoxide62]

Be surprised to see gas meter dial moving when only pilot valve open , but hey ho if the OP is seeing the dial move who am i to disagree , maybe pilot injector has been removed.

 

[bengasman]

There should be no gas flow without a flame. As this could be an uncontrolled gasleak, you should turn the gas off at the meter and get a pro in to make sure all is safe.

 

[dexion7]

thanks for the help guys - will get a pro in

 

[Agile]

Be surprised to see gas meter dial moving when only pilot valve open , but hey ho if the OP is seeing the dial move who am i to disagree , maybe pilot injector has been removed.

That thought also crossed my mind.

But then I wondered if the connections to the solenoids had been swapped over. But of course the second stage opening requires the pilot stage to be open first as they are in series gas wise.

I have heard of the OP's fault in the cc but not encountered it yet myself.

Tony

 

[dexion7]

well, my pal who is a gas safe fella but only does installs and not repairs looked at it an hour ago and confirmed what i reported on here:the gas valve is indeed opening without ignition.

he fixed the ht lead as that was cracked and set the elctrode gap to the correct size (apparently it was far too big). he took the injector apart and cleaned that out as well. it now sparks reliably every second but there is no pilot and gas valve still opens without the boiler starting properly.

the boiler does now sometimes fire up after a while (about 30 seconds) and he reckons that this is due to the continuous sparks from the ignition lighting gas which has flooded the area round the ignitor rather than from the pilot.

he is coming back later on to have another look but says that it may be a new gas valve required.

 

[gasafengineer]

Has the boiler been left on or isolated?