How to deal with water hammer from washing machine?

poppellerant

For the last couple of years, I've put up with water hammer from my machine when it stops filling. I'd like to try and put a stop to this, or significantly reduce it.

Access to the pipes is difficult as they go behind the kitchen cupboards etc. I'm not confident enough in my DIY skills to take kitchen cupboards apart to look for loose pipes, so I have been looking at water hammer arrestors.

I bought this water hammer arrestor from Screwfix. Wickes and B&Q didn't have any in stock - strangely they seem a rarity.

Because it would make my washer stick out too far by attaching the arrestor directly to my washing machine, I attached it to the end of the metal pipe where the washing machine water inlet hose would usually connect to. I then attached the washing machine's inlet hose to the opposite side of the arrestor, with the other end of the hose connected directly to the washing machine.

Now I still get banging, but not as bad. But I was hoping for a more significant improvement. Should the arrestor be attached directly to the back of the washing machine? Should I buy another arrestor? Or should I even buy a different type of arrestor - if so which?

Looking forward to some suggestions which mean I don't have banging pipes when I wash clothes.

stator

Is your stop !!!!(word for a male hen) turned fully on?


The last time I had water hammer, it was solved by fully opening the stop !!!!, as it waas partially closed. Not sure why

tonyh66

stator wrote: »

Is your stop !!!!(word for a male hen) turned fully on?


The last time I had water hammer, it was solved by fully opening the stop !!!!, as it waas partially closed. Not sure why

I had the opposite, had turn the stopkok down to stop the water hammer and squealing taps.

poppellerant

Thanks for the replies. I have tried ensuring that the stopcock is fully opened. If I turn it down then it the hammer reduces, but so does the water flow as you would expect.

Lorian

Is this a dishwasher with an aquastop type valve at the end of the inlet pipe, or is the valve in the machine?

The arrestor doesn't really need to be at the back of the machine - but despite what the instructions say I'd make sure its orientated like in the picture with the air reservoir area pointing upwards.

holding the pipes while the thing shuts off can often give you a good feel for whats going on.

neilmcl

Lorian wrote: »

Is this a dishwasher with an aquastop type valve at the end of the inlet pipe, or is the valve in the machine?

The arrestor doesn't really need to be at the back of the machine - but despite what the instructions say I'd make sure its orientated like in the picture with the air reservoir area pointing upwards.

holding the pipes while the thing shuts off can often give you a good feel for whats going on.

It's a washing machine.

Lorian

ok Glasses on now not sure washing machines use aquastop, so that rules out the issue they can get.

martinthebandit

Turn the tap on the cold water feed to the washing machine down slightly.

Your machine will fill slightly slower but it should stop the water hammer.

poppellerant

It's a Bosch washing machine. I'm sure it doesn't have Aquastop, which seems to be some sort of flood protection from looking online?

Thinking about it, I don't remember which way the arrestor is fitted - I didn't think it was too important. But I will look shortly, adjust as needed and update if I need to.

poppellerant

Turns out I did install arrestor upside down - I didn't realise there was a right way up. Now the arrestor is pointing up, the hammer is still there, but it has definitely improved.

DavidFx

The chamber on the arrestor has to be full of air for it to work - When you refitted, did you check the chamber was free of water?