Gloworm Ultimate 40FF Blows PCB Fuse

[Gillo]

I found this thread on a different forum.

http://forum.plumbingpages.com/glow-wormultimate-nightmare-vt708.html

It sounds like the same issue as me. I am getting about 76ohms across the fan, which seems about right. I guess I will need to fit a new PCB to diagnose whether the real cause is the fan, gas valve, AFM or just the PCB?

Dave

 

[corgiman]

Well like the man in othopedic shoes I stand corrected

just change it

 

[ACOperson]

I had a Glow worm 30ci not firing, no fan on but pump turning. When aps made it fired. Fan not jammed & resistance was OK according to Glow worm and was getting 240 volts into it but not working, fan worked when put on flylead direct to mains, however not when pcb driven. All wiring continuity OK.

PCB at fault methinks, changed it, nothing. Same symptoms.

New pcb back in box, old one back in, new fan installed, boiler works fine...

WTF??

Change both components, yes its expensive but it saves time messing around. If PCB ends up being OK then sell on Ebay or something...

 

[ChrisR]

Intermittent shorted turn in the fan, would do that. (Reads OK on ohms, though not on an L/Q meter)

Change both components, yes its expensive but it saves time messing around.

Sometimes that's best. The aim isn't to (only) change the minimum or charge the minumum, it's to get the darned thing back working again.

 

[ACOperson]

Agreed

 

[geoff@cetltd]

Since then I have had a good look at the PCB (unbolted from its carrier) and underneath the circuit board I can see that it has burnt out.

Has it actually burned to black i.e. carbonised ?

If so, then yes, carbon conducts and this could be the problem

 

[Gillo]

Yes it has burnt through a number of connections underneath the board!

I should be receiving my new PCB early next week!

Thanks

Dave

 

[Gillo]

I changed the PCB and fan and it now works ! I did not test the old fan with the new PCB so don't know if it was actually faulty, although the boiler seems quieter now.

Thanks for all of your help

Dave

 

[Soggy_weetabix]

I am a heating engineer with no electronic knowlege.

Never understood how...

1: the g/v solenoid can blow a 3amp fuse
2: the PCB will blow the fuse (or fuses) on the board) plus the 3amp in the fused spur.

Id love you experts to enlighten me!

All I will say about this boiler, is Im fed up with arming myself with a pin vice and guitar wire to clean the blocked pilot injector when their 'usual engineer' has shoved a lot of labour and parts and it still wont work.
AND try cleaning an LPG injector.

A hair off superman might work but I can never track him down.

David

 

[corgiman]

I changed the PCB and fan and it now works ! I did not test the old fan with the new PCB so don't know if it was actually faulty, although the boiler seems quieter now.

Thanks for all of your help

Dave

well done you

sorry I tried to get you to bark up the wrong tree