Sensitive Glowworm PCBs

[Electric Magic]

I was doing an EICR a few weeks ago and turned everything off to test. When I turned everything back on (main switch first, then RCDs, then one MCB at a time) the boiler, which had been fine before, had developed a fault, which it turns out was because something had happened to the PCB when I switched it back on. The boiler is on its own dedicated circuit but I'd left the FCU switch in the closed position when turning the MCB back on. My only guess is that (despite turning on the MCBs one at a time) I created some kind of surge when switching everything back on. Fortunately I've never experienced this with any other boiler despite doing the same thing many times (e.g. leaving the FCU switch closed when turning back on). The heating engineer who came to replace it mentioned that the Glowworm ones are particularly sensitive and he'd had one go just from turning the FCU back on.

Just wondering if anyone else had experienced this with a Glowworm or any other boiler brand?

 

[Leesparkykent]

Maybe the sfcu wasn't double pole.

 

[Electric Magic]

Maybe the sfcu wasn't double pole.

It was closed so that wouldn't make a difference I think. If I had switched it off before switching the MCBs back on perhaps it would not have happened, but I didn't realise that might be necessary as I'd never heard of it being an issue before (or experienced it myself).

 

[Leesparkykent]

So you sent sent 500V up the boiler PCB if the switch was closed?

 

[Electric Magic]

No hadn't done IR test at that point. Would of course have switched it off for that

 

[DPG]

The trouble with electronic equipment is that they all rely on switched mode power supplies and electrolytic capacitors. Now normally these things will run happily for years, despite the electrolyte in the capacitors gradually drying out over time. What you may find though is that if something that has just sat there for years running happily 100% of the time is switched off, it may not start back up. Daz