Gas CH Clunking

[chrissa1]

My Central Heating is making a clunking noise quite loudly after it fires up/clicks off on the thermostat.

Is this something I can sort myself or should I ring my kind landlady.

[AlBags]

If you can find the 'clunk' it's probably a copper pipe twitching when pump starts (under head of pressure) stick some foam pad or cloth in the gap.
It's often on the large pipes near pump.

[chrissa1]

Would it be near the boiler or in the Airing Cupboard upstairs. It's a really loud clunk. Is it dangerous?

[AlBags]

Well anywhere between the two or near pump.
Maybe close to a floorboard .. you'll have to listen while someone operates!
No not dangerous at all .. just annoying.

[firewatch]

are u sure its the central heating?? we have water hammer in the pipes which clunks regulalry something to do with the pressure and air, despite bleding all the radiators no joy yet

[AlBags]

Water hammer is the same thing .. but often caused by loft header tank ball-valve not seating properly .. or a poor rising main stopcock.
Try turning down stopcock pressure just a bit.

[chrissa1]

Thanks guys.

[firewatch]

oooooh thanks will give it a go!x

[chrissa1]

Can I do this myself or should I get a man in?

[AlBags]

Can you find the source of the rattle/knocking?
Tried waggling the pipes where they might be touching something?
You should be able to look around airing cupboard while someone turns pump or heating on and off on thermostat or boiler control.

[rccatnap]

I had a similar problem after a new installation. The installer came in and adjusted the non-return valve near the boiler. Took five minutes.

[JonnyBoy12]

I would ring to kind landlady to cover yourself. If you try to fix it yourself then you would be liable if anything goes wrong.

[chrissa1]

rccatnap, I think the noise is coming from above the boiler so it might well be that. Jonnyboy, I'll ring her on Monday. Thanks to albags too