Buzz in Glowworm Ultimate 80FF LPG even when it's not running

[John in Suffolk]

I used my Glowworm Ultimate 80FF LPG boiler yesterday with no problem, but then it started making an almighty buzzing chattering noise. I turned it off at the control panel but the noise continued until I turned off the power switch. Now, a day later, it makes the same buzzing noise when I switch the power back on even though I have the control panel off. I know nothing about boilers but saw on a post here that it might be the pcb. Is that the likely problem, and if so will I need a new pcb or can the current one be repaired? The boiler is about 20 years old. I am due to move in 2 months so want to avoid major expense! Thanks in advance for whatever help you can give.

[harry]

It might be associated with the circulating pump.

[John in Suffolk]

replying to harry, John in Suffolk wrote: Thanks for this. The circulating pump has been louder than usual lately, though the noise is very different and also in a different location. The buzzing noise I wrote about is in the boiler unit downstairs while the pump is upstairs. So it's hard to imagine how the two could be linked unless it's the controls to the pump n the pcb (?) that is causing the problem.

[Brian Gaff]

First identify what is making the physical buzz might be a good start, if its a dc pump then its probably getting aAC instead which is not good.

Brian

[Peter Parry]

Give Geoff at CET Ltd a ring on 01923 229224

). He has an encyclopedic knowledge of boilers and their faults and can supply refurbished PCB's at a fraction of manufacturers prices if necessary.

[Vir Campestris]

I've used him.

Andy

[Russ17]

replying to Vir Campestris, Russ17 wrote: If you have a Ultimate PCB with a two fuse, 7 wire arrangement and the relay (RL3 ) chatters constantly, check and replace C4 (50V 100uF). This capacitor provides the smoothing of the rectified DC voltage that provides a permanent DC supply voltage to RL3 (Relay for circulator pump). The DC supply voltage dropped on mine to 36V, which is too low for the relay to be held on, so it cycles between on & off. Replacing C4 at a cost of 30p solved it