Glowworm 50FF Boiler problems

[Help-Flymo]

Hi

I had a glowworm boiler fitted about 5 years ago and recently it has been doing strange things, it seems to function normally until it has operated for about 15-20 mins (or has warmed up) then the fan will come on as though its going to light up then it stops then almost immediately does it again this time it may light up but then stop immediately.
It gets in this cycle for several minutes and then will light up and function as it should.
A central heating engineer said it could be a circulation problem but that has all been checked out and pump works fine on the maximum speed.
Could this be a PCB problem? How reliable are the PCB's in this series of boiler?
Any help or advice from anyone will be greatly appreciated.
HF

 

[cross thread]

could be pcb .but i would check air pressure switch and flame ign/rectification first

 

[Help-Flymo]

gordongas

Sorry, should of mentioned that this has all been checked when it was serviced a few weeks ago.

HF

 

[Help-Flymo]

Does this sound like a PCB problem?

HF

 

[Alfredo]

Can you identify the boiler a bit better..is it a Glow Worm Micron 50FF or a G Worm Ultimate 50FF..or sommat else.

Alfredo

 

[Help-Flymo]

Hi Alfredo

Its a Glowworm Micron 50FF.

Thanks...
HF

 

[Rob]

Not greatly familiar with this boiler, however i have known PCB problems with similar symptoms to yours.

in that rads only warm to a certain temp before the boiler cuts off. not too sure about cutting off during ignition sequence.

 

[Soggy_weetabix]

Change the thermistor.

As unreliable as the PCB on this boiler.

David

 

[Alfredo]

Glow Worm Micron: If the PCB has Orange neons for the burner/reset then it has the original unreliable PCB and there is a high probability of it being faulty. If it has Green neons then it has an upgraded PCB which is less likely to be the cause. We've had very little trouble with thermistors and PCB covers about 85% of the problems we see on them, and we have loads on the area. My last service on Friday was a Micron 50FF and i really like them. We only stopped installing them in about 2002/2003

If it is an orange neon PCB then remove it carefully and look for signs of scorching on it. This is usually a dead giveaway.

Alfredo

 

[corgiman]

dont forget its a good idea to change the thermister to a new oneif you change the PCB

I have changed loads and have always had to go back to change it so I just do it now

I have no idea why though perhaps the lads could hazard and explination

 

[Help-Flymo]

Thank you all for your replies....

Alfredo - It does still have the orange neons for the burner/reset. I have just purchased a new PCB for it and will give that a go.

Thanks again.
HF

 

[Help-Flymo]

Replaced the PCB and the thermistor a few days ago and so far the boiler is working great!

Thanks once again..........

HF

 

[fireblade900]

hi mate just read the problem you've been havin with the PCB and was wondering were you bought one from and for how much tks john

 

[AlanE]

This thread is almost 3 years old fireblade!!