water hammer- washing machine

[mildwin]

loud thud when washing machine fills with water then sunddenly stops again, i.e. when it does the final rinse, lots of short bursts of water, then stops. new washing machine, old one did it a bit but not as obvious as this. i read up that it was possibly water hammer, called plumber. he came today, said that he didn't know why it was doing it, all pipes are ok, water comes from mains so no water tank. said it could be the actual machine itself, as it is new the opening & closing mechanism is in tip-top condition so the open & closing sound quite loud 'might quietly over time'. advised me that the pipes were in no danger & that , unfortunately we would just have to put up with it. thankfully it doesn't do it any other time, taps fine, etc, just when pumping water in machine. any ideas? is the plumber right in his diagnosis or is there actually something that can be done to prevent this? thanks

[scotman]

This sounds like classic 'water hammer'. The only way I know to get rid of it would be to feed from supply that is not at mains pressure. It is probably the new machine closing the valves faster that is making it louder that it used to be.

[The Builder]

just to add to Scotty's comments ....................... bit of trial and error I'm afraid, but I've found these to be effective.............

http://www.toolstatio...BSP/d20/sd2696/p93058

[mildwin]

i have no idea when it comes to plumbing, hence the reason I called a plumber (& the fact that its a rented property so i didn't actually have to pay!). so a water arrester thingy would work? how does it work & how easy is it to fit?
is the plumber right in saying that it would have no detrimental affect on machine, pipes, etc?

[ChuckFickens]

you could try simply turning the tap the water pipe from the washing machine is connected to half off.

be aware if you turn it off too far the machine may time out while trying to fill with water, in which case simply turn it on a little more

[mildwin]

i did ask the plumber that same question, whether it was worth doing it but he said it wouldn't make too much difference but could cause problems filling up the machine. basically the plumber could not advise me, he wasn't too bothered by it though as he said all pipes & connections were fine. so i am none the wiser really...

[Wak]

You could try turning on a cold tap at the sink when the washing machine is filling as this would tend to reduce the water pressure at the machine and may reduce the thud each time. If this helps then try turning the main supply tap off slightly to see if it has the same effect.
If it doesn't help then maybe it is the new machine being too energetic !!!