House banging and shaking when turn hot water heating on

ellay864

A few days ago we heard some banging noises that were on and off for a short while, but gradually got louder. It seemed to be coming from the boiler or somewhere that side of the house, and at first had sounded like trapped air in pipes but then seemed louder than we'd have expected for that. When we turned the water heater off (it had come on via it's timer) it stopped. We put it on again and the banging resumed and was horrendous, it felt like the house was shaking. We have BG service plan so called them out, the guy looked at the pump (on cylinder in upstairs airing cupboard) and said that seemed OK then went out to the boiler in the garage. He came back holding an old pot of black stuff and said we needed a power flush, and that the gunk in the system was clogging things. He did something that he said would fix it temporarily and for a few days it worked (although the noise from the pump seemed worse!) but today it's back worse than before.
The quote for powerflush was £600 (lifetime guaranteed if we keep our service plan with them) and I've read threads on here saying that BG will use that for any problem. I've done a bit more reading round and I know we have an open system with a header tank and expansion tank in the loft. I am rubbish at heights and hate going up into the loft so wanted to find out what I should be looking for when I go there - don;t want to go up there for nothing!
Any advise on that would be welcome. Please don't tell me about doing DIY flush jobs as neither me nor OH are comfy at doing that as we've each seen bad experiences. I don't mind paying for a job to be done properly but just want to check things out before just handing over money I dont have to BG. I am trying to get hold of a local plumber to come and give me an opinion but wanted to check out as much myself as I can to arm myself with info for him

BaldPlumber

Go up into the loft and check the expansion / header tank has a few inches of water in it and the ball valve is working OK.

ellay864

OH went into the loft...there's 2 tanks and he said both were full. I'd heard something about there should only be a few inches in them but he said it was fine as the ball valves were working - no idea what exactly he saw/meant but when i asked about the fact it was full he seemed to think it was fine. I can feel an 'I told you so' moment!!

Canucklehead

Hi,

Those of a cynical nature would say the BG guy had a jar of sludge in his tool kit, to be brought out in situations like yours, and shown to you,
'Viola, you need a powerflush Rodney'

In the meantime he's turned the pump speed up to max (or maybe freed it up) to get you by for a day or two, knowing it will fail again and reinforce his 'diagnosis'.

I would be looking at a failed /failing pump as well. A flush would probably be a good idea and a Magnabooster2 filter fitted on return to boiler.
An independent RGI would be a cheaper option, and be no more or less effective than BG.
For a lower budget fit a new pump (if this is the problem) and the filter.
Might be a faulty boiler stat, but the fact BG went to the pump and all was well for a while makes me home in on that.

Someone recommended to you by friend or family. Or Gas Safe Register (site currently down) search.

GSR.

macman

The same every time...
The man from Del Monte, he say 'yes!'
The man from BG, he say 'powerflush!'
Even if it did need one, that is about twice what a local independent RGI would charge.
Canucklehead's advice is spot on-go elsewhere.

Enterprise_1701C

Stupid question time from someone that knows very little other than a mistake a friend made. Is your water temperature set very high, or is the thermostat working?

ellay864

Just had an independent plumber round that I've known lots of people recommend and he has also said it needs a flush...can't say I'm exactly jumping for joy but does reassure me somewhat getting another opinion saying the same but without the BG interest

Lgas

I hate that BG have this awful reputation for pushing powerflushes. Not all BG engineers are like this, a few pushy ones just make the rest look bad. Lets face it, what's going to get passed on to family and friends, a bad experience or a good one? I've never personally seen any BG engineer with a ready made jar of sludge, but i'm sure they're out there.

FWIW I would go straight to the pump...any parts/components affected by sludge are not covered by your homecare agreement but I would have thought they would replace the first one for free then advise you to take 'preventative measures'. e.g powerflush and magnabooster. At least with BG a powerflush is guaranteed for the lifetime of the boiler.