Help, boiler won't ignite

[rehab71]

Any help appreciated. Came home tonight to no heating or hot water.

The boiler is a Glow Worm Ultimate ff40 and should ignite automatically when you turn the knob. Any ideas?

Thanks

[dirkgently]

Has the over heat button popped out?
Otherwise the fan or pcb.

[rehab71]

dirkgently said:

Has the over heat button popped out?
Otherwise the fan or pcb.

No, it's not popped out. Guess I need a plumber/heating engineer.

[smifffymoto]

I reckon it's the thermal cut out.Its a thin bit of copper wire with a bigger bit of copper on one end.

[smifffymoto]

I reckon it's the thermal cut out.Its a thin bit of copper wire with a bigger bit of copper on one end.

[stevensdrs]

Most likely the fan is kaput.

[It's fixable...]

I'm with the other guys - most likely culprit is the fan.

Turn the power off to the boiler at the fused spur.

If you take the top half of the cover off you will expose the workings of the boiler.

At the top you will find a pressed steel snail shell with a small electric motor on the top. This is the extract fan that pulls the gas fumes out of the boiler and chucks them out of the flue.

You can be fairly sure that the motor bearings have cooked and the fan itself (hidden out of sight inside the snail shell) has dropped down and has fouled the inside of the case and cannot turn.

On the snail shell you will see some little hoses that run to a small electric device - this is a pressure switch that checks the fan has spun up and is safely extracting the exhaust gases before the boiler controller will allow the gas burner to fire.

Hope this helps - you can find the fan on the internet, but you need a gas safe engineer to replace the failed part.

[tc153]

When was the last time it was serviced? If you remove the case you need to check the seal integrity when refitted or it can spill products of combustion. Get a recommended engineer out.

[rehab71]

Thanks all. Was serviced a few weeks ago

My dad reckons the fan. Engineer coming early next week.

[LookAtMyCat]

rehab71 said:

Thanks all. Was serviced a few weeks ago

My dad reckons the fan. Engineer coming early next week.

It's a good bet but to be honest it's pretty impossible to say without actually taking the cover off and diagnosing it (which you need to be GSR to do). Luckily a broken fan is always the easiest thing ever to diagnose on a boiler so if it is, you should be sorted very quickly.

I rarely touch the fans on a service. I know some guys grease them up etc but I was always told by my knowledgeable teacher that unless you had to, don't touch the fan.

[silversurfer1]

Demand

Thermostat calling ?

Fan

air pressure switch activated

GV1 open

Spark

Pilot lights

Flame rectification

GV2 open main burner

Thermostat satisfied

GV1 & 2 closed