Central heating pipes 'banging/knocking'

[glenno1]

What make of valve is it,some budget valves can knock a bit

 

[callum84]

I would have to go home and check what kind of valve.

The noise doesnt seem to be coming from the TRVs or radiator, more in the floor leading up to the rad??

There is sometimes a 'thump' aswell as the rhythmic knocking/pinging, which could resemble the noise of a valve but again seems to be under the floor.

 

[glenno1]

My suggestion would firstly be to turn the valve when the heating is on and see if noise comes and goes

 

[callum84]

Ok i will try that tonight also

 

[petercj]

Have you tried pin-pointing where the noise is coming from by using a pipe or a tube to your ear.

If the grippers were already down, could they have added some nails to firm them up?

If this noise is being caused by expansion/contraction just below a board, you should be able pin-point the spot by using a tube to your ear.

Does closing both radiator valves make any difference?

 

[callum84]

I seem to have pin pointed it to the spare room at the opposite end of the property to where the boiler is.

I tried switching the trvs off and on when the noise was happening but this did little difference, I have however found that when the trv is turned down to the lowest Setting, there seems to almost be a 'static' type noise coming from it?? Then when rad heats up it seems to go??

Also the more rhythmic bangs are when the rad is heating up/cooling down, followed by a louder thud on what seems to be the pipe nearer the hall (next to spare room) almost sounds like a valve type thing closing??

 

[callum84]

To be honest the TRV seems pretty crap, when u turn the damn thing to the lowest setting, it can actually turn further?!?

It seems just now (as the rads cool down) as if the trv is on a lower setting, the banging seems to be a lot less frequent?

 

[petercj]

When I had this kind of noise it was a 15m pipe feeding a radiator valve - they'd brought the pipe up through the floor alongside a joist with a knot in it, then when the rad was connected up, the pipe was hard up against the knot, and it made a hell of a noise. It would start slowly.. bang.......bang ........bang and then speed up bang...bang...bang...bang... then slow down again. This was in a bedroom too! Drove me to drink in the end!

Until I'd freed it up, I couldn't believe something so simple could make such a racket! I removed some of the knot using a small drill, and that was it, job done, all quiet again.

Could the carpet fitters have found a loose or creaky board and nailed it down tight before laying the new carpet?

If someone has laid a pipe under the floor and left a board loose over a pipe that was already tight in a notch, that could explain things.

I never knew why the problem I had started - the house was 20 years old, and it just started up one day.

 

[callum84]

Impossible to say if they have I would have to contact the carpet company and check I think, I don't think the carpenter would admit it even though he had done tho, especially if it has caused an issue.

Just hoping the plumber on Friday can physically do something to help as it is becoming quite depressing really, the thought of having to lift the new carpet and then the floor boards doesn't help either lol!

The more and more input I am getting it seems to be a problem which will need floor finishes lifted rather than anything else but I really hope not.

 

[petercj]

Try the easier possible solutions first.

If you do end up lifting the carpet, you will probably be able to spot any new nails or screws.

Also, look for boards with tongues missing.

 

[callum84]

Thanks petercj, if it did come to lifting the carpet, is it easy enough to see where the issue would be in your opinion?

I guess it would be a case of looking for the pipe work tht is shuddering or coming in contact with the joists/flooring?

Earlier tonight again it was the regular light banging/pinging which reduced as the trv was turned down, then a londer thump, which as I mentioned almost sounded like a valve closing in the hall subfloor, would the typical system have valve type components?

It is probably very evident that I know very little about heating systems unfortunately, but appreciate the time and effort this form has given me.

 

[phpaul]

Thanks petercj, if it did come to lifting the carpet, is it easy enough to see where the issue would be in your opinion?

I guess it would be a case of looking for the pipe work tht is shuddering or coming in contact with the joists/flooring?

Earlier tonight again it was the regular light banging/pinging which reduced as the trv was turned down, then a londer thump, which as I mentioned almost sounded like a valve closing in the hall subfloor, would the typical system have valve type components?

It is probably very evident that I know very little about heating systems unfortunately, but appreciate the time and effort this form has given me.

ok back to basics is a hatch so u can crawl under the sub floor ? if so investigate that way

 

[petercj]

Chances are your plumber will recognise the sounds when he hears them - might be something quite simple, I wouldn't worry about it too much.

 

[glenno1]

Im sure your plumber will do couple of checks and find what it is

 

[callum84]

Thanks guys, I appreciate the positivity!

In terms of a crawl space, it is literally big enough to get into, the subfloor is not deep at all, so although access I available, it is REALLY restricted, and where the hatch is you would have to crawl a good few meters, and there are dwarf walls running opposite direction to the joists every 1500mm or so, so really it's not great for working underneath the floor or even getting a look.