Water Hammer after new bathroom installed

[Cazza]

Hi

I've recently had a new bathroom installed. I've noticed when I flush the downstairs loo there was a hammer type noise under the bathroom floor when the cold feed for the loo turned off/ same with the washing machine.

So I turned off the mains water supply. Opened the highest tap first (bathroom sink) and then all the others down to the lowest , which I thought was the garage water tap (about 2.5 ft off the ground). This appeared to work! Great I thought, until I switched on the dishwasher and ran a bath upstairs. Whilst in the bath I noticed every time the cold feed for DW stopped it clunked/ hammered under bathroom floor, even rattled the new towel rail.

I tried the downstairs toilet again and sure enough the same hammer noise is back!

Any ideas? One thing i notice when running the bath is that the flow isn't brilliant and seems to be a bit spurty. And after I turned off the mixed taps it throws out water 3 times over several seconds. I bought these taps as seconds in a reputable bathroom place but wonder if they are faulty? Can they cause air locks?

Or was it that I needed to have the dishwasher on when I drained the system? The dish washer was all plumbed in etc but not turned on when I drained the system.

My house was built in 1978 and not sure if it has air chambers

Any ideas gratefully received.

Cazza
P.s. I tried ringing the bathroom fitter but he is ignoring me. Its worrying as he's used all push fit stuff and I had the bath switched around, and toilet cold feed moved slightly and sink moved. So now all the pipes are loose under floorboards/ bath and not fixed. Can't easily get the boards up anymore as they've put hundreds of screws down in a plywood floor (ready for me to tile onto)

 

[exedon2]

If you had no noise previously and you have now get the fitter back!
I would suspect unclipped pipework.

 

[Cazza]

If you had no noise previously and you have now get the fitter back!
I would suspect unclipped pipework.

Thanks, yes that is what i'm thinking. But i've texted him and sent a video and he won't reply! I had so many problems with those fitters from damaging the electrics, to not using the right waste pipe (cutting down old one), things put in wrong places, creating new floor squeaks (when they were supposed to repair them) the list is over 20 things. I was polite about it all but I think they are cowboy fitters and once they had my money they have run for the hills. They probably don't know what "guarantee" means..
So now i'm going to have to get a plumber in and they'll probably have to disc cut up my bathroom floor to reach the pipes to clip it all! Worst nightmare!
They were recommended to me by a reputable bathroom company who have showroom and i'm going back to them next week to tell them everything! No one else should have to go through all this, they don't deserve to be on any fitters list they are so unprofessional
Many thanks

 

[Knappers]

Floppy pipes will do it but hammer can happen without those too.
If it wasn't for the loose pipes then I'd recommend shock arrestors on offending appliances and possibly checking supply pressure and fitting a pressure reducing valve and a little buffer if appropriate but it sounds like it might be a bit like 'lipstick on a pig' in this instance....

 

[Cazza]

Floppy pipes will do it but hammer can happen without those too.
If it wasn't for the loose pipes then I'd recommend shock arrestors on offending appliances and possibly checking supply pressure and fitting a pressure reducing valve and a little buffer if appropriate but it sounds like it might be a bit like 'lipstick on a pig' in this instance....

Many thanks for your reply.
I was thinking the same, that I could get a shock arrestor (air chamber?) on the cold feed pipe in garage for toilet cold feed and washing machine, another one inside the house for the dishwasher. But as you note I've also got loose pipe or pipes under the bathroom floor now. The pipe comes up the toilet waste pipe box in and to toilet feed. Have attached photos showing how the plumber has put a push fit on old cold feed as taps the other end now, this is now loose I can move it up and down (it then makes a knocking noise half way across room under floor when I do this, not sure what its knocking on, probably towel rail pipes. I also attach 2 photos I took in the hole under bath showing a maze of pipes in between the joists which run parallel to wall. I think the bath cold feed looks like it doesn't come from the toilet cold feed but from under floor side of bath parallel to it directly from boiler (same as hot water feed). I can't tell exactly where the water hammer is under the floor. The cold feed that i'm holding onto in photo does vibrate but if I hold it tight it doesn't stop the hammer.
I'm thinking I may have to get a plumber to disk cut up the plywood floor (as unfortunately new tiles covering edge of plywood). Also photo attached shows how the floorboards underneath have been cut. These will also be covered top end by tiles so they won't come up easily either and will need to be cut again (hopefully not creating new floorboard squeaks) by towel rail to be able to get underneath to clip the cold feed pipe. Its a nightmare and will be costly job to do I imagine. Not great after already paying thousands for the refit job.

Its strange how when I run a bath seems like an air lock is created which causes this hammering of the cold feed. Wonder if that can be resolved and therefore I wouldn't need to clip pipe

The hammer effect might simply be from where the toilet cold feed copper pipe was replaced with a shortish push fit and now the pipe up the toilet waste box in is loose. In which case the floor needs taking up in a different area

The crazy thing is the boiler is right next to the new taps end of bath/ shower. I thought they would create new copper pipes from boiler to bath/ shower, not use old piping system with push fits

 

[Cazza]

Many thanks for your reply.
I was thinking the same, that I could get a shock arrestor (air chamber?) on the cold feed pipe in garage for toilet cold feed and washing machine, another one inside the house for the dishwasher. But as you note I've also got loose pipe or pipes under the bathroom floor now. The pipe comes up the toilet waste pipe box in and to toilet feed. Have attached photos showing how the plumber has put a push fit on old cold feed as taps the other end now, this is now loose I can move it up and down (it then makes a knocking noise half way across room under floor when I do this, not sure what its knocking on, probably towel rail pipes. I also attach 2 photos I took in the hole under bath showing a maze of pipes in between the joists which run parallel to wall. I think the bath cold feed looks like it doesn't come from the toilet cold feed but from under floor side of bath parallel to it directly from boiler (same as hot water feed). I can't tell exactly where the water hammer is under the floor. The cold feed that i'm holding onto in photo does vibrate but if I hold it tight it doesn't stop the hammer.
I'm thinking I may have to get a plumber to disk cut up the plywood floor (as unfortunately new tiles covering edge of plywood). Also photo attached shows how the floorboards underneath have been cut. These will also be covered top end by tiles so they won't come up easily either and will need to be cut again (hopefully not creating new floorboard squeaks) by towel rail to be able to get underneath to clip the cold feed pipe. Its a nightmare and will be costly job to do I imagine. Not great after already paying thousands for the refit job.

Its strange how when I run a bath seems like an air lock is created which causes this hammering of the cold feed. Wonder if that can be resolved and therefore I wouldn't need to clip pipe

The hammer effect might simply be from where the toilet cold feed copper pipe was replaced with a shortish push fit and now the pipe up the toilet waste box in is loose. In which case the floor needs taking up in a different area

The crazy thing is the boiler is right next to the new taps end of bath/ shower. I thought they would create new copper pipes from boiler to bath/ shower, not use old piping system with push fits

I've attached drawing below of how I think all the pipes are all connected. The grey pipes are the old copper pipes and non grey pipes are the plastic push fits. The horizontal lines are the joists.
I'm guessing that the towel rail heating pipes has nothing to do with the water hammer? That its only the hot and cold water pipes?
I think the old copper hot and water pipes will be clipped where cut into the joists. But then the cold pipe to bath did appear to vibrate one time with the hammer.
I really can't tell if the noise is coming from the toilet cold feed or the bath cold feed, as it all echoes under the floorboard. In theory it should be the toilet cold feed as that comes from downstairs where the cold water flow hammer shock wave must come from. But then why did the bath cold feed pipe vibrate if its not connected to the toilet feed.
The mains water feed to the house comes in near to box waste pipe in kitchen (right hand top corner). How a cold feed pipe then gets to the boiler upstairs I don't know, looking at the boiler it looks like it might come across the upstairs floor rather than directly below the boiler. So maybe it comes up the boxed waste and across to the boiler somehow. Perhaps its this pipe to the boiler that vibrates with a water hammer effect downstairs.

 

[Cazza]

I've attached drawing below of how I think all the pipes are all connected. The grey pipes are the old copper pipes and non grey pipes are the plastic push fits. The horizontal lines are the joists.
I'm guessing that the towel rail heating pipes has nothing to do with the water hammer? That its only the hot and cold water pipes?
I think the old copper hot and water pipes will be clipped where cut into the joists. But then the cold pipe to bath did appear to vibrate one time with the hammer.
I really can't tell if the noise is coming from the toilet cold feed or the bath cold feed, as it all echoes under the floorboard. In theory it should be the toilet cold feed as that comes from downstairs where the cold water flow hammer shock wave must come from. But then why did the bath cold feed pipe vibrate if its not connected to the toilet feed.
The mains water feed to the house comes in near to box waste pipe in kitchen (right hand top corner). How a cold feed pipe then gets to the boiler upstairs I don't know, looking at the boiler it looks like it might come across the upstairs floor rather than directly below the boiler. So maybe it comes up the boxed waste and across to the boiler somehow. Perhaps its this pipe to the boiler that vibrates with a water hammer effect downstairs.

Having thought about it i'm sure there is a push fit cold feed from toilet to bath straight along the top. This used to be a copper pipe that mid way along had a feed to a sink that was where the towel rail now is. This would have acted as a rigid fix for the copper pipe. Now its a free floating plastic pipe. I remember I could lift the new cold feed for toilet up as the push fit below was floating. It also explains why when the hammer effect occurred the towel radiator vibrated as the pipe must have knocked against the towel radiator pipes.

So as as Exedon2 said its a lack of clips in this long loose plastic pipe causing the hammer effect.
I think my options are to either lift up flooring and clip pipe in one or two places. Or to have a couple of air chambers put in downstairs pipe work.
I will have to try and charge these costs back to the original fitter who failed to clip new pipe work if he doesn't want to come back to correct his mistake