Glowworm Cxi F.12 fault

[Zippymark]

I've been to have a quick look at my mate's boiler and its displaying F.12 which is 'Connection fault between main pcb and display pcb'. The boiler is not firing up. The wire itself seems ok, no obvious breaks/damage (have not actually tested yet). I've had a word with a couple of people and it's looking like either the main PCB or the display pcb, but at £200/£150 odd i don't really want to take a chance. Is there a way to test this? I've had a look on a few forums and it doesn't seem to be an easy one to get the bottom of.

If anyone has had this, what did it end up being?

One thing that might be worth noting is before the fault code came up, they said the pressure was jumping all over the place and making a bit of a noise.

Thanks for any help

 

[diamondgas]

I've had 2 main pcb's die on me just by interrupting the power! If you ring glow-worm tech they step you through the procedure for testing whether the correct voltage is being transmitted to the display! Not something to share here in open forum and to be honest I can't remember off hand ! lol

:welcome: to the forum by-the-way Zippymark

 

[Zippymark]

Cheers, that was going to be my next step. I thought it was going to be the expansion vessel or something because i was just told the pressure was dropping.

 

[diamondgas]

Cheers, that was going to be my next step. I thought it was going to be the expansion vessel or something because i was just told the pressure was dropping.

The two boilers I'm talking about, by-the-way, didn't display any fault codes they just died!! I've also had issues with the push on connectors giving off erroneous faults too!

 

[neily01]

The two boilers I'm talking about, by-the-way, didn't display any fault codes they just died!! I've also had issues with the push on connectors giving off erroneous faults too!

I had a glowworm i had to replace the pcb on. A kind electrican after i had put the boiler on a plug top and left the link in place to get it going decided to come and rewire including the programable stat as required, got the wires back to front on a 24v switching boiler! Best bit he had never tested it so it was me the next day who turned the boiler on at the spur for it to go bang! Lucky enough knew the glowworm rep well and he drop me off one foc with a new set of ignition elecrode to solve the explosive ignition threatning to rip the boiler off the wall! Had a rear flue as well quite scary to watch that flue on intial fire up.