Glow worm 70FF ignition lockout

[Dave Andrews]

Moderators note:
(This appears to be copied from the Screwfix forum)
Note that this forum does not support DIY gas work.





I have a glow worm 70FF, I have maintained it carefully, replaced the PCB with a later revision level and replaced the igniter fairly recently. It hasnt been entirely trouble free but now is exhibiting a problem (ignition lockout). It does it’s startup cycle, lights happily but cuts out after around 5 seconds,it will try three attempts all of which cause the boiler to ignite followed by cut out, solid reset light and fast flashing burner on light, my initial thought was the thermistor as a failure here would cause the board to think the burner had not lit after 3 attempts, but there is a separate light error sequence for thermistor failure. It isnt an overheat as the water feed is cold as is the boiler and the fan runs normally.

Please, does any one have any clues before I start replacing things willy nilly.

Thanks in advance

Dave

 

[CBW]

Again, possibly borderline gas advice. If you’re an engineer the join the gas part of the site. Why did you replace the pcb?

 

[Dave Andrews]

It was the older style PCB which was unreliable at best with phantom resets, after replacement the boiler was fault free for 3 years or so.