• We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Water hammer?

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
Help!..
I have lived in my current house for the past twenty two years and something has changed. Everytime I flush a toilet (I have 3) the water pipework makes a loud groaning/farting noise. If I then open a tap, anywhere in the house, whilst the cistern is filling, there is a buzz in the pipework. The time the cistern takes to refill seems to be longer than it used to, which suggests that the supply pressure has dropped. Could this cause the noises? I thought water hammer was caused by excessive pressure.
 

Chems

Established Member
Joined
23 Apr 2008
Messages
4,065
Reaction score
0
Location
A Wood Haven
We had this in our house, it turned out to be that a run of piping in the loft had popped out of its clips and it was resonating and making all this noise when water was flowing.

Water hammer is when you close the outlet of a high pressure supply and the pressure reflects back off the closed valve back down the pipe/hose causing damage.
 

SketchUp Guru

Established Member
Joined
12 Apr 2005
Messages
3,152
Reaction score
0
Location
Rochester, MN USA
It sounds to me as if you have air in the pipes and need to add an air vent. HEre in the US it is normal to install air vents through the roof to allow waste gases somewhere to go. These also helps to prevent the hammering. There are also smaller vents available to allow air to escape the system. these are typically mounted under a sink or some place else out of the way. If there's air trapped in your plumbing, that could cause your cistern to fill slowly.

Maybe you have a vent or two and they are plugged?
 

sparkymarky

Established Member
Joined
19 May 2010
Messages
217
Reaction score
0
Location
holsworthy devon
probably un-clipped pipes as chems said, water authorities can raise the mains supply pressure and any given area without notice so it may be that you have had a slight increase in pressure lately.
another possibility which i have had before is quarter turn taps on the mains supply where the ceramic disc is bouncing off the plate which it seals against causing a loud banging, do any other taps drip when the water hammer is making the noise?
 

theturner

Established Member
Joined
4 Feb 2012
Messages
42
Reaction score
0
Location
North Yorks
I have had the same problem in the past. It turned out
to be just a new washer needed on the offending tap.
Roger.
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
theturner":4zj3cm0g said:
I have had the same problem in the past. It turned out
to be just a new washer needed on the offending tap.
Roger.
It's not the tap that is a problem. The noise starts immediately when the toilet is flushed.
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
Dave R":hiuozlyh said:
It sounds to me as if you have air in the pipes and need to add an air vent.
If this were the case I would expect to have the same problem with the taps. It only happens when a toilet is flushed. The cistern is filled off the incoming mains supply so there shouldn't be any air trapped.

I definitely don't have any vents to block as I built the house myself and did all of the plumbing, which was fine for 21 1/2 years

Thanks for your suggestion.
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
sparkymarky":3mqqkx9m said:
do any other taps drip when the water hammer is making the noise?
No. The noise stops very quickly after the flush and well before the cistern is full. Opening any tap in the house whilst it is filling causes a buzzing somewhere in the pipework. With a bit of care, I can even play a tune on it. It really annoys my wife. :)
 

theturner

Established Member
Joined
4 Feb 2012
Messages
42
Reaction score
0
Location
North Yorks
whiskywill":2wmcvjmu said:
theturner":2wmcvjmu said:
I have had the same problem in the past. It turned out
to be just a new washer needed on the offending tap.
Roger.
It's not the tap that is a problem. The noise starts immediately when the toilet is flushed.
The cistern is a tap.Change the washer and I bet a pint of water the problem is solved.
 

misterfish

Established Member
Joined
18 Jun 2006
Messages
1,523
Reaction score
5
Location
Chichester, West Sussex
We had this years ago in a toilet cistern. I changed the washer but this had little effect. Eventually I fitted a new valve that was described as 'quiet' and also 'eliminates water hammer'. It was and it did.

Misterfish
 

steadyeddie

Established Member
Joined
17 Mar 2011
Messages
283
Reaction score
3
Location
Whetstone, Leicester
Years ago, our cistern made a bit of a racket after flushing. The noise disappeared if the cold tap was turned on. Changing the washer in the cistern cured it completely.

Dave
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
Thanks for the many and varied suggestions. I'll try 3 new cistern washers. If that doesn't work, anybody want to buy a house?
 

tomatwark

Established Member
Joined
30 Oct 2010
Messages
1,147
Reaction score
0
Location
Scottish Borders
My parents had this problem when they flushed their bathroom toilet.

We thought it was a water pressure problem adjusted the pressure with the stop tap and it cured it.

For a time, when I visited next, it started to do it again as the main bathroom is only used when they have guests.

I took off the cistern lid and found that there was a little plastic nut with a mesh inside it that was lying in the bottom of the cistern, that should have been screwed onto the end of the valve, it had worked lose over time and fallen off.

Put it back on problem cured instantly.

Tom
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
At last! Yesterday evening I changed the diaphragm/washer in the ball valve in the noisiest cistern and it worked. Silent flushing. I have now got to do the other two and I can use the toilet at night. No more bed wetting. :D
 

hanser

Established Member
Joined
19 Jan 2010
Messages
510
Reaction score
0
Location
Nottingham
whiskywill":10ep68oh said:
At last! Yesterday evening I changed the diaphragm/washer in the ball valve in the noisiest cistern and it worked. Silent flushing. I have now got to do the other two and I can use the toilet at night. No more bed wetting. :D
I bet that's a relief :lol:
 

Lons

Established Member
Joined
14 Feb 2010
Messages
7,682
Reaction score
370
Location
Northumberland
whiskywill":18n4bljn said:
Thanks for the many and varied suggestions. I'll try 3 new cistern washers. If that doesn't work, anybody want to buy a house?
It almost certainly is not all 3 cisterns. If it happens whichever WC is flushed then the real problem is within the pipework system and it becomes a process of elimination. try adjusting the main stopcock then try to track down the source of the noise (might mean a crawl in the loft :( ). Sometimes with plastic pipe especially, if it comes loose from the clips (not always fitted anyway :roll: , it can belly up causing an air pocket.

If it's the result of 1 WC , ( does your comment about being slower to fill mean all or 1 cistern?,) then the likely cause is the inlet valve. If the older type, metal or plastic with arm / ball float then washer is easily changed. Check also that the float isn't holes and waterlogged. If the newer type, it's better IMO to change the whole valve. personally, I wouldn't use a cheaop version - just aren't worth the effort.

I change around 10 - 15 a year, nearly all newer versions - the oldies were much longer lived.

Bob
 

whiskywill

Established Member
Joined
8 Nov 2011
Messages
1,802
Reaction score
2
Location
Sunny South Wales
Lons":hz307hpz said:
It almost certainly is not all 3 cisterns. If it happens whichever WC is flushed then the real problem is within the pipework system and it becomes a process of elimination. try adjusting the main stopcock then try to track down the source of the noise (might mean a crawl in the loft :( ). Sometimes with plastic pipe especially, if it comes loose from the clips (not always fitted anyway :roll: , it can belly up causing an air pocket.

If it's the result of 1 WC , ( does your comment about being slower to fill mean all or 1 cistern?,) then the likely cause is the inlet valve. If the older type, metal or plastic with arm / ball float then washer is easily changed. Check also that the float isn't holes and waterlogged. If the newer type, it's better IMO to change the whole valve. personally, I wouldn't use a cheaop version - just aren't worth the effort.

I change around 10 - 15 a year, nearly all newer versions - the oldies were much longer lived.

Bob
Changing the first 26p diaphragm lessened the noise made by the second cistern. Changing the second diaphragm lessened the noise made by the third cistern. Changing the third diaphragm stopped all noise completely. I feel that there has been a general slowing of the filling rate which I can't change because the stop tap is fully open. There are no pipes in the loft. It is a self build house and all pipes are copper. They run in between and through the first floor joists and only reappear very close to their end points so no chance of checking for loose pipes unless I rip up carpets and floorboards.

However, all is now peaceful and, once again, thanks for all suggestions.
 

Lons

Established Member
Joined
14 Feb 2010
Messages
7,682
Reaction score
370
Location
Northumberland
whiskywill":2bnvcpv0 said:
Changing the first 26p diaphragm lessened the noise made by the second cistern. Changing the second diaphragm lessened the noise made by the third cistern. Changing the third diaphragm stopped all noise completely. I feel that there has been a general slowing of the filling rate which I can't change because the stop tap is fully open. There are no pipes in the loft. It is a self build house and all pipes are copper. They run in between and through the first floor joists and only reappear very close to their end points so no chance of checking for loose pipes unless I rip up carpets and floorboards.

However, all is now peaceful and, once again, thanks for all suggestions.
:oops: Sorry about that, I somehow missed a couple of previous posts so didn't know you had sorted it. The odds against all 3 cisterns would be huge unless it has developed over a period of time or you've had a bad batch. Cheap fix though :)

I managed to sort out a water hammer problem yesterday co-incidentally though not the same cause. The guy had fitted a 3 bar shower pump as part of a diy bathroom refurbishment and each time it shut off it set off a hammer in a stud wall. The wife was threatening divorce and didn't relish plasterboard removal so as I have a flexi inspection camera I drilled a small hole near each joist and found that the builder had pushed 15mm copper pipes through the noggins and they weren't clipped. It hadn't happened previously so the pump was the cause but as I hadn't supplied it and they didn't want to spend more, the solution was to squirt expanding foam through the holes and let it set. Sorted and hopefully the foam shouldn't cause future problems though I did put in a disclaimer :wink:

Bob
 

Latest posts

Top