Boilermate II - delay timer issue?

Hi all

I've seen a lot of posts around concerning pumps running constantly or not at all but nothing relating specifically to this issue (might be because it's blindingly obvious!):

My new house has a boilermate II (probably installed mid-90s when the place was built) and a 3 year-old Worcester conventional boiler. When the boiler stops firing it starts making some really unpleasant banging, gurgling, hissing noises.

I figured it sounded like boiling and have checked to see if the pump overrun is working - it isn't. The boiler stops firing and the primary circuit pump stops immediately.

1. Is there anything other than the delay timer pcb that could be causing this?
2. Is it easy to swap the pcb over and should i do anything else at the same time?
3. If i leave it for long will it knacker my boiler's heat exchanger?

Any advice very gratefully received.

Sounds like the delay timer PCB.
Also check your unit is full etc.
Read through the posts on here ref BM II's
All has been covered many times.
Mike

Thanks for the response Mike. I had checked the cold feed and it's fine. The noise only ever happens when the boiler stops firing, unlike on other posts I can find. Others also seem to have problems with constantly running pumps, not early cut-off. Sorry if I'm not searching properly!

Have ordered the delay timer PCB and will report back when I've found a moment to do it.

Thanks

The BM II takes water from the F & E tank ok then?

Hi Mike. Yes, as far as I know the boiler is taking water fine. I drained a little water from the tank with the supply to the F&E closed and it drained the F&E. It then filled back up fine. Also, it seems the other posters having trouble with banging have it happening when the boiler's on, not just after switching off. I've got the PCB sitting at home now and just waiting for an opportune moment to fit it.

It is hard to say on a forum.
But banging can be;
Sludge in pipe work / boiler.
Pump not running on the delay timer board.
Sluggish pump?
Mike

Since the pump isn't running at all immediately after the boiler stops firing i guess i'll try the Delay Timer PCB first. After that, i'll go through your other suggestions. It's really useful to have that list. Maybe it would be an idea to give it a few weeks with some X400 anyway seeing as i've just bough the place and don't know how well the previous owner looked after the system.

Cheers