Central heating pipes 'banging/knocking'

[petercj]

Have you tried exorcism?

 

[callum84]

Next on the list mate, are you offering to perform it? :crazy:

 

[phpaul]

Thanks guys, I will try turning the TRV off in the offending area as suggested.

GrahamM, can you explain abit further when you say TRVs on the wrong end?

The 4 suggestions you gave, would they just 'suddenly happen' or get worse so to speak? Its just that as far as I can remember last week there was not any issues or they were less apparent, it seems to have got worse all of a sudden?

turn on heating hold the pipes into rad . does the one with the trv on heatup first ? look at the trv is there an arrow on the body of the trv to indicate direction of flow does the arrow point to the cooler pipe

 

[callum84]

Thanks phpaul for constructive input, I will try that this evening.

 

[petercj]

Next on the list mate, are you offering to perform it? :crazy:

Just trying to be helpful!

A woman in Lower Sodbury reported a similar problem - turned out to be a BG fitter who had got stuck in the cupboard under the stairs when doing a gas-check ... been there ten days, and no one had missed him!

 

[petercj]

Seriously now ... I once had this problem and it was expansion and contraction of a pipe that was tight on a joist.

But then why would it suddenly start out of the blue?

If no work has been done in and around the house, then maybe a joist has moved slightly for some reason, settlement perhaps, or possibly has become damp and has swollen - it would only take a tiny amount of movement.

If the knocking only occurs when the system is heating up, or cooling down, it's worth checking out. First step being to try and pin-point the area the sound is coming from. Try using a tube or a pipe put to your ear on any suspect areas.

Might also be worth running the heating on very low temperature to see if the knocking doesn't happen then.

 

[callum84]

We did have a carpet laid about a week ago in the Bedroom, but I didnt think that would have caused an issue? Ie there wasnt excessive banging but Maybe it has?

 

[petercj]

We did have a carpet laid about a week ago in the Bedroom, but I didnt think that would have caused an issue? Ie there wasnt excessive banging but Maybe it has?

If they nailed down new carpet grips, they may have tightened up a board, or even caused a slight shift in a joist.

If the pipe was tight before, then just a fraction of a millimeter could make the difference.

The floor can act as a sound board, and it's surprising how much noise can be created by such a simple thing.

 

[glenno1]

Are the grippers touching the pipes

 

[callum84]

Glenno1: No the grippers were gown originally and were re-used.

Can such a thing like the grippers/laminate touching the pipework (as per my previous post) above floor level cause knocking/pinging noises??

 

[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.