Banging pipes - help !!

[chrisward]

Hi

I recently registered on this site as a last resort for my pensioner mother who's at the end of her tether. For the last 12 months she's been hearing banging noises from the pipes. It sounds similar to someone banging several times on the wall and it appears to originate from the immersion closet in her bedroom. She has an immersion heater and no central heating. Over this period of time we've tried the following, calling on 3 different local plumbers.

Water pressure adjusted
New Immersion
New tank
New Ball cock
Called Severn Trent Water to check the meter outside. They found a fault with it and replaced it but still the banging continues.

As you can see we've tried most things at considerable expense.

Can anyone out there offer any advice, or have come across something like this before ? The plumbers we have used seem baffled. I know it screams "water hammer" but I don't see how it can be. It's never occurred when the washing machine is on or when the toilet is flushed.

Thanks

Chris Ward
Stafford

 

[chris watkins]

Hi Chris & welcome
Can we have a bit more info please,
1. When does the noise happen ? i.e. all the time, first thing in the morning or only when the cylinder is being heated ?
2. Can you confirm that the hot water cylinder is feed via the water tank in the loft & is the immersion on economy 7 or a timer ?
3. What does it sound like ? are the bangs close together, do you know what water hammer sounds like ?

 

[Plum Bob 66]

Hi There Chris

You say ballcock was replaced, was this in the cold water storage tank or are you referring to the toilet. Does the banging occur after any particular action ie turning the taps on ?

Bob

 

[chrisward]

Hi Chris & welcome
Can we have a bit more info please,
1. When does the noise happen ? i.e. all the time, first thing in the morning or only when the cylinder is being heated ?
2. Can you confirm that the hot water cylinder is feed via the water tank in the loft & is the immersion on economy 7 or a timer ?
3. What does it sound like ? are the bangs close together, do you know what water hammer sounds like ?

Hi Chris

In answer to your questions:

1. the noises happen at all times of day. Initially they were going off in the middle of the night. Then my mother started turning her water off at 10pm, and the banging then occurred in the day time. To my knowledge it hasn't gone off while the immersion heater is heating up.

2. There is no water tank in the loft. The immersion tank has a separate smaller cylinder that's part of the same unit. This takes water from the mains and keeps the main immersion tank topped up. The immersion tank is heated via a timer on the mains for 1 hour a day starting at 12.20 pm. Her house does have economy 7 and the timer did heat the tank during the night hours but we changed it a while ago, again to avoid the noise in the night. The new tank we had fitted has a thermostat to stop it overheating.

3. The banging lasts for 3 or 4 seconds, usually consisting of smaller bangs to start with and ending with 1 or 2 louder bangs. I haven't heard water hammer first hand but I understand it's a rapid banging, and is only supposed to happen when water appliances are being switched on or off.

Hope this makes it a little clearer.

Thanks

Chris

 

[Cds]

Water hammer is caused by the sudden closing of a valve which sets up shock waves bouncing up and down the pipework. The likelihood ofwater hammer occurring is dependant up on two factors, how quick the valve is closed and how fast the water is flowing.

If it is water hammer then a valve must be shutting, possiblya ball valve in a tank or WC or a solenoid valve in a washing machine/dishwasher. You need to identify the valve and reduce the flow rate to the valve. If this does not work then you can fit a shock arrestor just before the valve.

You could try reducing the flow rate of the mains cold waterby closing the incoming stopcock a bit as a short term solution.

 

[chrisward]

Hi There Chris

You say ballcock was replaced, was this in the cold water storage tank or are you referring to the toilet. Does the banging occur after any particular action ie turning the taps on ?

Bob

Hi Bob

The ballcock in the cold water storage tank was replaced and the banging does not occur after anything being turned or on off (or flushed).

Cheers

Chris

 

[JCplumb]

So turning the water off at the stopcock cures this?
If that is the case water MUST be being drawn somewhere when the banging occurs. When the water is turned back on in the morning can you hear it flowing for a short while? If so you need to find out where it is flowing to and you will have found your problem. Check everything including outside tap, any water features in the garden etc.
If you can't find the problem you could fit a rester as close to the origin of the noise as possible. See here - Rester from Toolstation
While typing this I had another idea, could it be possible that water usage from another property connected to the same main would cause this? I've not heard of it, but I suppose it could be possible if someone hasn't adhered to regs. Maybe even a commercial site with high usage nearby?

 

[chris watkins]

Hi Chris

In answer to your questions:

1. the noises happen at all times of day. Initially they were going off in the middle of the night. Then my mother started turning her water off at 10pm, and the banging then occurred in the day time. To my knowledge it hasn't gone off while the immersion heater is heating up.

2. There is no water tank in the loft. The immersion tank has a separate smaller cylinder that's part of the same unit. This takes water from the mains and keeps the main immersion tank topped up. The immersion tank is heated via a timer on the mains for 1 hour a day starting at 12.20 pm. Her house does have economy 7 and the timer did heat the tank during the night hours but we changed it a while ago, again to avoid the noise in the night. The new tank we had fitted has a thermostat to stop it overheating.

3. The banging lasts for 3 or 4 seconds, usually consisting of smaller bangs to start with and ending with 1 or 2 louder bangs. I haven't heard water hammer first hand but I understand it's a rapid banging, and is only supposed to happen when water appliances are being switched on or off.

Hope this makes it a little clearer.

Thanks

Chris

Hi Chris
It does sound a strange one ! (excuse the pun) I think it is a case of trying to eliminate things one at a time. I does seem that from what you are saying we can eliminate the hot water system (expansion & contraction).
If you turn off the mains water & the noise stops it suggests that it is indeed the water system, I agree with Cds & JC it is most likely some form of water hammer it may not be emanating from your property, surge pressure are common within the supply system albeit normally at night but if your property is a flat or shares a supply it could be coming from outside. This would be best tackled with the installation of a shock arrester or small expansion vessel installed any were on the mains but I would suggest in the cylinder cupboard. As this is a relatively cheap thing how about going back to the company / plumber who carried out the work in the first place which I assume was done to try to solve the problem in the first place & ask them to come & install it free of charge, as a good will gesture, as the other work did not solve it (even if you paid for the materials).
Please let us know how you get on.
CW

 

[tipintim]

In answer to your questions:

1. the noises happen at all times of day. Initially they were going off in the middle of the night. Then my mother started turning her water off at 10pm, and the banging then occurred in the day time. To my knowledge it hasn't gone off while the immersion heater is heating up.

Must be a faulty stat, or set to high. Is it a combination cylinder? If it is, she is hearing it boiling over. (the lid is probably jumping with the heat lol)
I bet the cold water storage is as hot as the hot water cylinder. Time to upgrade mate.

Read more: http://www.ukplumbersforums.co.uk/plumbing-forum/41396-banging-pipes-help.html#ixzz2A3Uk2Vb9

 

[chris watkins]

Hi Chris

In answer to your questions:

1. the noises happen at all times of day. Initially they were going off in the middle of the night. Then my mother started turning her water off at 10pm, and the banging then occurred in the day time. To my knowledge it hasn't gone off while the immersion heater is heating up.

2. There is no water tank in the loft. The immersion tank has a separate smaller cylinder that's part of the same unit. This takes water from the mains and keeps the main immersion tank topped up. The immersion tank is heated via a timer on the mains for 1 hour a day starting at 12.20 pm. Her house does have economy 7 and the timer did heat the tank during the night hours but we changed it a while ago, again to avoid the noise in the night. The new tank we had fitted has a thermostat to stop it overheating.

3. The banging lasts for 3 or 4 seconds, usually consisting of smaller bangs to start with and ending with 1 or 2 louder bangs. I haven't heard water hammer first hand but I understand it's a rapid banging, and is only supposed to happen when water appliances are being switched on or off.

Hope this makes it a little clearer.

Thanks

Chris

Have a look !!

 

[tipintim]

Who ? I charge to look...:drunk:

 

[chris watkins]

Not very much I hope !!!! LOL

 

[chrisward]

Hi again

Well here we are 17 months down the line and still the banging noise persists in my mother's house. We've had more plumbers out - all are at a loss. I asked the last one to secure a pipe which was loose in the airing cupboard where the immersion cylinder is situated. The banging did seem to change for a couple of days after that and actually 4 went days without banging at all - but it's back to it's usual behaviour now. Does anyone know the approximate costs/implications of having someone remove the floorboards and checking the pipework underneath ?? I feel this is the only way this will ever get sorted. Unfortunately the floorboards are not separate strips and look like one continuous piece so I guess this complicates matters a little more.

At this rate I'm going to be writing a sympathy letter to the BBC or somebody out of sheer desperation !!

Any feedback is appreciated - my poor mum won't go to bed now is even starting to wonder whether the problem is structural, even though everyone assures her it isn't.

Cheers

Chris

 

[stoker122]

Hi Chris,
Did you have a shock arrestor fitted?

 

[chrisward]

Hi Chris,
Did you have a shock arrestor fitted?

No we haven't. I've seen it mentioned many times during my research though. My local plumbing supplies shop suggested one but none of the plumbers we've had round did, which surprised me a little. One thing that's stopped me having one fitted is that I read that you're supposed to have it fitted as near to the source of the banging as possible. As we're not sure where the banging originates I can't convince myself that it will do the trick. Are they expensive ? (Mum's already spent nearly 1K on this problem).

Cheers

Chris

 

[chris watkins]

Hi Chris
You should have trusted another Chris & had one fitted (or even two) can't do any harm. & low'ish cost to buy & install you could diy it.
Toolstation > Plumbing > Valves > Mini-Rester

 

[Crinkmeister]

Whats inside that - some sort of spring loaded plunger?

 

[chris watkins]

They are normally a mini expansion vessel type arrangement i.e. bladder / membrane with water on one side & gas on the other.

another type / design

 

[rtrevor]

Hi Chris,

Did you manage to find what was causing this or find something that worked to stop it? We have a similar problem in our house - shutting off the stopcock to the house stops the banging, so it seems to be something in the house causing it, but we've tried shutting off every appliance / taps connected to the cold water individually and cannot find the cause.