strange water hammer problem

[nigelp]

Hi, first of all I'm not a plumber, but am hoping for some advice!!

My neighbour and I are suffering an ongoing problem where if she uses the washing machine, a few hours later there is a water hammer effect all along the pipework. This goes on for hours and it’s difficult to sleep through it.

We live in a block of flats – the noise reverberates all along the communal hallway to the water meter cupboard. The noise even makes that cupboard door reverberate, and you can see the central dial of her flat’s water meter pulsing almost exactly every 15 seconds while it goes on. I have attached a link to an icloud based video (55MB) showing this. (The noise is much louder than apparent from the video.)

Download Video Attachment

This is a new build block of flats, and we have only been in a few months, buts its gone on from day one. The snagging team and contractors who fitted the water supply cannot find anything wrong with the pipework, although they have lowered the water pressure which makes the noise less apparent.

Hotpoint have also been to check the washing machine (new and supplied with the flat), and again cannot find anything wrong, but I feel the engineer probably didn’t try very hard as he could reproduce the issue.

My own feeling is that there is either a problem with the water meter (about 10 out of 70 flats did have faulty meters which needed replacing, though this wasn’t one of them), or the water inlet valve on the washing machine is at fault.

We are struggling to get any proper investigative action taken. (I suspect what is really needed is a plumber who can come round and investigate – at night – while the noise is occurring!). The snagging team say its the washing machine and the washing machine engineer is saying its the pipework.

Generally the noise kicks in some time after the washing machine has been used, and almost always late at night.

Any thoughts or advice please?

Cheers, Nigel

 

[Howsie]

Get someone to cut a small dead leg filled with air as a temp fix and then get a decent company to come and fault find. I'm quite sure I know why it's happening....

 

[nigelp]

Thanks Howsie, I did see similar arrestor devices on Amazon. This is actually my neighbour's machine but I'm trying to do some pushing myself to get it fixed (given it keeps me awake!).

I phoned the developer again this afternoon and explained about the useless engineer visit. He is now going to arrange a replacement machine. I will see if that fixes it.

I'd love to know why it's happening!

 

[Ch4 plumbing]

Thanks Howsie, I did see similar arrestor devices on Amazon. This is actually my neighbour's machine but I'm trying to do some pushing myself to get it fixed (given it keeps me awake!).

I phoned the developer again this afternoon and explained about the useless engineer visit. He is now going to arrange a replacement machine. I will see if that fixes it.

I'd love to know why it's happening!

As suggested a shock arrestor (small expansion vessel) should resolve this issue, usually becomes apparent when there is a water meter fitted as this will have a non return valve within its set up.

 

[zzzjim]

I phoned the developer again this afternoon and explained about the useless engineer visit. He is now going to arrange a replacement machine. I will see if that fixes it.

I'd love to know why it's happening!

I think its a feature of modern machines taking lots of short fills rather than just a few thuds.

( Changing machine may not work )

 

[Masood]

My neighbour and I are suffering an ongoing problem where if she uses the washing machine, a few hours later there is a water hammer effect all along the pipework.

This is the bit I find baffling. Why a few hours later???

 

[Howsie]

Probably the original closure putting pressure on a FOV and forcing that to pass somewhere along the line.