DIY Doctor UK DIY Forums

Hello, probably a commonly asked question so I do appologise if I'm going over old ground. I have a water hammer problem which is literally sending me mad and I'm just looking for advice on the best way to sort this out for my particular system.
My system is fed direct from the mains through a combi boiler so I have no tanks in the loft or anything like that. On every single tap/washing machine/shower when it is shut off the unmistakeable thud from the pipes happens. The only time it doesn't happen is when the toilet refills. Problem is I can't seem to narrow down exactly where the thumping is coming from, it seems to be from pipes enclosed in the wall cavity running from downstairs in the kitchen to upstairs. Now I've heard of fitting arrestors but if this is happening on every tap closure do you need one for every one? Also I have checked as far as I can all pipework is well clipped down so Idon't think it is a fixing issue.
Any advice greatly appreciated.

Hi rich65912

Problem usually caused by vibration, possible due to high (mains) pressure, when you turn the tap off, the sudden stop, jolts the pipework, also as you say, its also due to bad ‘clipping’.

1. Try closing the ‘stopcock’ a ¼ turn.

2. For the price of a 10p washer and 15 minutes, replace a tap washer and see if it makes any difference, if so, do the rest.

If it is bad you will need to sort it as it ‘may’ damage the pipework & joints.

Regards

Skids

R,

YOU COULD TRY REPLACING A LENGTH OF THE CW MAINS COPPER PIPE WITH POLYTHENE PIPE TO INTRODUCE A BUFFER AND IT DOES NOT AMPLIFY THE SOUND/VIBRATION AS COPPER PIPING DOES.

WHERE YOU CAN AVOID TURNING TAPS OFF QUICKLY AS THIS CREATES THE POTENTIALLY DAMAGING PRESSURE WAVES THAT "SKIDS" REFERS TO.

A.