noisy boiler

[pandaman]

I have a 14 year old Glow worm convential boiler. A few weeks ago I drained and flushed the system after desludging with x400, after draining I had a plumber in to replace some partially blocked pipe work in the airing cupboard. A few days after being back in use the boiler started to make what I can only describe as loud popping/banging noises a few minutes after start up, more so when the hot water only is on than when the central heating is on. After about 10 minutes the noise fades away. It is a bit of a pain as we usually have the hot water on before getting up in a morning and the noise wakes me up, though not my wife who could sleep through an earthquake!
I do not think it is kettling as I have had that before and the noise is very different. Anyone any ideas as to what it could be.

 

[Agile]

Sounds like air in the system, a partially blocked or sluggish pump or a blocked feed pipe not fully filling it.

Tony

 

[david17uk]

Could be any of the 3 mentioned above, check them all

My guess would be a blocked cold feed pipe, causing air in the system.

 

[JohnD]

bleed the highest radiator in the house and see if water squirts out forcefully.

Did you clean the mud out of the F&E tank before refilling?

 

[pandaman]

Thanks for replies. Yes I cleaned out f&e tank properly before refilling. On bleeding upstairs rads, all on same level, water comes out with a good pressure. Cold feed pipe to pump was one of the pipes replaced, system had a good flushing through, I did that myself, System has X100 added on refill. Plumber did say pump impeller looked a bit gunged up but don't think he did anything about it. Is it worth having the pump off again? If it is air somewhere what is the solution?

 

[Agile]

Plumber did say pump impeller looked a bit gunged up but don't think he did anything about it.

Obviously I dont know if the fault lies with your plumber or yourself.

As the owner and in the absence of any other information I would blame you as you are clearly aware of problems but nothing was done about it!

Tony

 

[corgiman]

tony why are you being mean

I think the punter was asking for advice NOT who is to blame.

 

[poolebybirth]

how would a sluggish or partially blocked pump cause these noises? how would you check? am asking as i have had similar noises on start up but never though of it being a pump!

 

[steved101]

a blocked/sludged up pump will take longer to kick in to action and therefore will not shift the water quick enough at 1st and hence the noises

 

[Agile]

A boiler needs an adequate flow of water through it to remove the heat its producing.

The pump is that most likely cause of your problem.

As it has already been commented by your plumber that it has a problem that is the first think that should be inspected.

Look at the FAQ on this site for "The Finger Test".

Tony

 

[poolebybirth]

good point but wouldn't the noises be all the time if the pump was to blame, and not just for the initial 10mins?

 

[Agile]

I give the advice ( free by the way ) and its up to you if you want to take it or not.

Obviously you think you know more than I do about boilers!

You also must think that I am a "plumber" and that all plumbers leave school at 15 are are thick so obviously you will know more that I ever could because of my limited intelligence and education. I also start my sentences with a capital letter.

Tony