Glow Worm Fuelsaver 35F Woes

[Otto Sump]

Hello, I have a Glow Worm Fuelsaver 35F, its quite old but with regular servicing its been very reliable, that is up to now. Tuesday morning the boiler was turned on and the following was noted. Pilot lit straight away, continuous sparking but no main burner, extract fan running. I done a bit of research on this forum and made the following repairs. Resoldered all joints on PCB, (quite a few dry) WD40'd the extract fan, hoovered all the internals of the boiler, blew air pressure switch and tubes.Still the boiler is the same, it lights sometimes but its hit or miss. I did notice that a couple of times when I tapped the side panel the pilot would extinguish, re-light (would I be right in thinking that this is due to the air pressure switch doing what it should be) then sometimes it would work again. Also I can hear the solenoid switching very fast, 3 or 4 times in succession before lighting. Any information would be gratefully appreciated, moneys a bit tight at the moment hence the request.
PS: Can anyone tell me why this boiler has two solenoids, is it a diverse system?
Kindest regards
Dennis, Sunny Whitehaven Cumbria.

 

[Soggy_weetabix]

One is the pilot light solenoid, and other is main burner solenoid.

Basically your lighting sequence is as follows:

Fan operates
This will operate a/p switch
Power to pilot solenoid which opens
Spark igniter operates and ignites pilot
Ignition spark switches off and second solenoid opens.

Your getting to the last phase of the sequence, so this rules out fan, aps and tubes.

So, it can be electrode / loose electrode leads, blocked pilot jet effecting pilot flame picture or that good old PCB.

David

 

[Otto Sump]

Thanks for the quick diagnosis David, and for enlightning me on the solenoids. I've just also noticed that the boiler main burn can inadvertantly switch of after only operating for a few minutes,(pilot stays lit) if left a while the main burner re-lights.

Just priced the PCB for this boiler, crikey anyone got a spare lying around.

Regards
Dennis

 

[kevplumb]

E mail chris r

 

[Otto Sump]

Thanks, email is [email protected]
Regards
Dennis

 

[ottosump]

Just to update this post, the fault was the boiler PCB, upon replacement the boiler worked fine, up until the fan ceased a couple of years later ( see other thread) and recent problems, but that's a different posting.
Regards Dennis