Water Hammer Device for Washing Machine or Dishwasher

My washing machine started to create water hammer recently and the pipes were banging every time the cold water valve shut (every few seconds during filling). I ordered this device which I initially thought would fit onto the 1/2” BSP (15mm) copper pipe feeding the w/m. It arrived in good time but I was disappointed to see it was sized 3/4” BSP (22mm). However, the existing stopcock and hose under the sink were sized 22mm, so all good.I shut the stopcock, removed the hose then fitted the hammer arrester in its place and the hose on top of that. It took two minutes.Meanwhile the water hammer had already stopped, I think because I had replaced a pressure reducing valve cartridge upstairs next to the unvented hot water cylinder. The PRV had started to leak and inspection showed it was cracking up. I suspect the PRV had been absorbing the water hammer since the w/m was installed but finally failed. Replacing it had stopped the banging but was maybe at risk of failing again after a while. Better to install the new arrester on the w/m feed but I can’t comment on how well it works because the banging had stopped anyway. Long story which I hope you follow.

Bought a new Samsung washing machine and from day one it caused terrible water hammer in my water pipes when filling. Having searched this seems to be a common problem for some people with modern machines. I was somewhat wary of buying this product but so far it seems to be doing the job. It took me literally about 2 minutes to fit directly to the back of my washing machine. The "hammer" has been reduced significantly. There is still some noise when the machine shuts the water on and off repeatedly - especially during the rinse and spin part of the cycle - but it has been reduced a lot. It will be interesting to see if the noise reduction continues.UPDATE:I have been using the valve for several weeks now and there has been a small increase again in the amount of noise when the machine fills, although it is still less than without this device fitted.

I had a bit of water hammer noise when the washing machine switches off its water. This device reduced the hammer noise a bit, but not completely. I think I need to clip down one section of pipe upstairs where the hammer noise can still be heard. It was very easy to fit between the washing machine hose and the tap - a 2 minute job with no skill needed. I used a 3/4" or 27mmm spanner to make sure the fitting is tight. My advice is to make sure that all cold water pipework is clipped down, particularly where the knock noise comes from, otherwise this device cannot be expected to completely eliminate pipe hammer.

Purchased and fitted this 6 weeks ago. 9 months after moving into a new house we had some plumbing work completed. Before this there was no problem with washing machine. washing machine was plumbed in to a new location, this was when water hammer started. Every time the water valve closed on the machine (which is up to 20 times a wash) there was a thud which sounded like someone banging on the wall with a hammer. Didnt matter what we did (adjusting water pressure, turning stop valve on off and opening taps etc, it made no difference. After fitting this device to the water inlet valve directly on the machine (which was simple, completed in 2 minutes) about 95% of the problem has been cured, there is still the odd faint;'clunk' now and again but nothing like it was before. Would definately recommend if you have a similar problem.

A dishwasher we had installed started rattling the water pipes from day one. Being totally useless at DIY, etc. I did a bit of Googling and managed to diagnose the issue as being water hammer and how it was not unusual with valves closing in dishwashers. A search on Amazon revealed this little gadget. I was a bit dubious about it at first, especially as neither my local plumber nor the 'plumbing expert' at B&Q had heard of such a thing. However, as it didn't break the bank I thought we'd give it a go. As mentioned, DIY and myself are not very well acquainted, so - as there were some other jobs for the plumber to do - I waited until he came round to install it. As it turns out, it's so easy to install I could indeed have done it myself - a 2-minute job, if that. It's now been in place for a couple of months and there's not been even the slightest hint of a rattle from the water pipes. As it comes in blister packaging, I'm not sure how we'd have been placed with regard to returning it if it didn't work. Amazon are pretty good about that kind of thing, though.

Simply amazing! Completely stopped water hammer. With out this fitted the cold water pipes in the whole house would shake violently. I followed the instructions and fitted it direct to the washer as the instructions advised and couldn't be more happy. Seems like new washing machines are causing a lot of problems with water pipes - my Samsung EcoBubble is just under a year old and has made so much noise. The old machine was a Indesit washer/dryer and we never had any water hammer in the pipes with that so the manufacturers should be investigating what their new equipment is doing - I'm sure in the USA class actions will soon be taken against these manufacturers for damage to property. But this simple cheap fix has saved the day

This works great. Before fitting this it sounded like somebody was hitting my pipes with a hammer and something was about to break. Just screwed this into the back of the washing machine. ( Careful not to cross the threads as it's copper fitting will cut new ones on the nylon of the machine ) Then, like they used to say in the adverts, "The banging was gone" ( or was that the dirt? ). It does stick out a little from the back of the machine but I have standard machine and counters and it fits fine.Although it looks a little rough it is very well built. The mating surfaces for the washers to seal on are good and flat so it makes a great seal.It says it can be fitted in any direction and I put mine sideways so it fits under the counter and it works fine.