Central Heating Help Please

anotherbigspender

I'm hoping someone can help me diagnose and fix a problem I am having with my central heating...

Poterton Puma 80e Combi installed approx 2000 in small one bed flat. Running 3 medium sized double rads, 1 small double rad in the bathroom and 1 single rad.

Symptoms are boiler will not fire even although room stat is calling for heat. Hot water is working fine and boiler fires without any problem when HW tap is opened.

I have a BG homecare agreement and have had an engineer visit last week. Surprise surprise he diagnosed sludge or a partial blockage in the system which could only be sorted by a powerflush. He said the pump, which is almost new, cannot move the heat round the system and the boiler is not firing up because it doesn't think heat is needed - the pipe that feeds the system from the boiler is red hot.

He fiddled a bit with the thermostatic valves on the radiators, closing some, opening others, 'cooled' the system down a bit by running the HW with the system off and then turning it back on again and then left saying there wasn't much he could do without a powerflush. He was going to call back the next day to book me in.

He never called and the system seemed to be working fine after he left so I didn't chase him but the same thing has happened again tonight, HW is fine but no CH.

Is the BG engineer spinning me a line, as I suspect, just to get himself some powerflush commission, or will it really do the trick for me? The best price he could give me for the powerflush and the magnaclean was £600 - a supposed £100 discount because my system is so small.

All advice gratefully received!

Thanks

dan23uk

A very common fault on the Pumas is the wax capsule in the diverter valve sticking in hot water mode, so the hot water will work fine, but when there is a call for heat, the boiler may fire for a few minutes, then overheat and shut off. There may be some residual heat on the flow pipe.

Make sure none of your hot taps are dripping, as even a very slow drip can keep the wax capsule/diverter in hot water mode. Or alternatively, isolate the mains cold water to the boiler, the wax capsule/diverter valve (if working correctly), should now move to heating mode and the rads should heat, which will prove the boiler itself it working ok, and would point to a drip or leak on the hot water side of things, If not, the wax capsule may need replacing.

Hope this helps

Dan

david29dpo

Agree with above. I would not trust BG as far as i could throw them.

gas4you

Wax capsule is a PITA to change. Probably why he didn't want to do it. Don't blame hime really, I wouldn't either.

macman

Strange how BG's solution to almost every problem seems to be a £600 powerflush...

anotherbigspender

macman wrote: »

Strange how BG's solution to almost every problem seems to be a £600 powerflush...

Indeed, hence my caution.

I think I am going to get a local indy to come and have a look and if its a part covered by homecare I'll get BG back in to do it.

Thanks all