Fix Water hammer and/or Water Pressure

Hi,

I am looking to cure my water hammer problem and was looking fot some tips. Its happening each time I flush the toilet and straight after the fill is cut off, same for taps and washing machine etc. I have an arrestor installed on the back of the washer and another under the sink (think its on the dishwasher pipe). The noise is really annoying now and worried that some damage is going to be caused somewhere and almost all pipes are behind the walls.

I also think I have higher than average water pressure (just my opinion) could this be related?

I did change the dual flush in the toilet recently however water hammer was evident way before then although im not sure if it was happening after the cistern fill like it is now (maybe it was and I have just tied the 2 together).

Along with that, we had a new boundary box/stop tap/water meter at the end of the drive recently, but again the water hammer was around before.

What can I do without spending anything if possible?

Do I drain the system? If so can someone give me some detailed instructions so I know which order to do it and which tap to open first/last?

Would lowering water pressure help? I tried turning the stop tap under the sink a lot of the way down until the kitchen tap showed an obvious decrease but then I went to flush toilet again and just seemed the same. Would doing similar to the outside one make a difference or should that be left fully open?

Any suggestions would be appreciated as its really annoying me now

Did you change the fill valve in the toilet, or just the flush? If you only changed the flush then you should change the fill valve, that's almost certainly the root of your problems. Go to Screwfix and buy yourself one of these

Turning your stopcock down does nothing to change the water pressure, it just reduces the flow rate. You need a pressure reducing valve to change pressure

Thanks, no I didn't as the one already in there seemed fine. That still wouldnt resolve the hammer I'm getting from shutting off taps, washer, dishwasher etc. though

I would like to try a TRV but not sure where to fit it. There is hardly any pipe under the sink for it to attach to

If I was a betting man, I'd bet you a good deal that changing your fill valve will solve all the other issues as well. Humour me, give it a go

Haha seriously? I struggle to find the link between cistern fill and my washing machine.

As it was annoying me, I just turned off the water and opened up all my taps, shower, outside tap to drain. Turned water back on and closed them off in reverse and it actually seems to have made a big difference. Not sure how long it will last....

OK yeah, didnt last long haha. Turned kitchen tap on, big splutter of air came out now everything back to how it was dammit

adzyp said:

Haha seriously? I struggle to find the link between cistern fill and my washing machine.

Click to expand...

They're connected to the same pipe. Every time the washing machine draws water, the pressure change causes the worn valve in the toilet to start the hammer. Seen it loads of times

Mmm okay, for £13 I supposre its worth a shot but im still struggling to be convinced that the fill falve has been the cause of water hammet throughout most of the house.

What would your suggestion be if I hadnt mentioned that id recently changed the flush?

I'd still have suggested that you change the fill valve. It's generally the cause. The only time I'd have said it's not the fill valve is if you'd said you'd already changed it

ok, ill go with that then

back to the PRV, that's still something I want to try and sort out as i definitely think pressure is too much and would like to at least have some control on it. What options are there on where to install one? I want it to control the pressure for the whole house ideally but there is nowhere to fit it outside and where the pipes come in under the sink there isn't much room in the line either side of the internal stop tap

If you don't have room on your existing pipework then you'll have to alter it to make a PRV fit

ok but where is the best location? before the internal stop tap or after?

After the internal stop tap and before any tees

Hi @muggles so just fitted the fluidmaster pro including the piece that goes in the bottom specifically for high pressure/water hammer....and it hasnt made the slightest bit of difference! Ha