Vibrations through house linked to feed and expansion tanks float valve

[MattJago]

Hi all,

Apologies for the lack of knowledge here, but I will try and progress with what the internet has taught me so far.

We bought our first house exactly a year ago, and all has been fine with the boiler and hot water system though the initial survey advised that the boiler was 20 years old and in need of replacing in the next couple of years. We have a gravity fed system.

Over the last couple of weeks (as the cold weather has started to come in to the UK), we have started getting sporadic loud vibrating noises after showers (we have a power shower which itself is very loud).

As it's a semi-detached and the vibrating news reverberate throughout the whole house (and we assume next door), this is something I've tried to investigate each time, but the noise can stop after 5-10 minutes.

I have managed to find that next to our large cold water tank in the loft, there is a smaller tank which I believe is a feed and expansion tank. Within it there is a cistern with a float valve, and although the tank has plenty of water in it, if I open the float valve manually, the vibration and sound quickly stops. There doesn't appear to be an issue with the float valve - it works fine, but there is always a lot of water in it which keeps the valve closed.

I believe the supply pipe that feeds the float valve is mains water (but that is only from what I've read online - it's hard to follow the pipes), so I'm not sure where that vibration is coming from apart from pressure within the pipes. I guess the other option is that it's pressure from the boiler and that is something I'll check when I get home.

Has any body experienced this or similar before, or have any advice?

Thanks in advance,

Matt

 

[45yearsagasman]

It will probably be the ball valve assembly in the main water storage tank. Vibrations are possible when it's starting to close down after refilling. Change it.

 

[MattJago]

Thanks for the response, Pete.

Would the ball valve assembly for the main water tank be linked to the float valve in the expansion tank? Opening the float valve instantly stops the sound.

Would replacing the ball valve assembly be something you can do yourself or is it best to get a plumber in?

 

[45yearsagasman]

Both tanks will be fed from same mains feed pipe. When the noise happens the sudden difference in pressure when you move the ball valve in the header tank stops the vibration.
Next time it happens move the float in the large tank to confirm what I suspect.
It's a simple job for a confident diyer, and 30 mins work for a plumber.

 

[MattJago]

Thanks very much, Pete. Greatly appreciated.

I'll give that a go next time the sound happens and if all goes as you suspect, I'll look into options for getting it replaced. 10 years renting properties means little real world access to fixing these types of things, so rather than make a mess it may be safer to get someone to do this until I've found my DIY feet!

 

[bernardgreen]

A ball cock damper may be helpfull.

This is a simple DIY fix.

Better options are available.

Sometimes a new washer will stop the vibration.

 

[45yearsagasman]

that made me laugh. Just change the assembly instead of a Bernard bodge. Yogourt pot my arse

 

[AGAS]

bernardgreen why go through the hassle with that contraption, it would be better to change the valve because with what you've suggested your only masking the problem and not dealing with the problem . blo@dy yogurt pot , come on bernard

 

[MattJago]

Thanks for the suggestion Bernard - I've now got a local plumber providing a quote for a new ball valve.

Thanks again for all of your help.

 

[bernardgreen]

of a Bernard bodge.

I copied the image from anotehr website, I totallly agree it is bodge. But it does work. The image points out the metal re-inforcing plate. With plastic tanks if that plate is not there then flexibility of the plastic can contribute to valve bounce.

 

[45yearsagasman]

If you agree it's a bodge, then don't post it!
After all we are professionals on here.

 

[oilboffin]

Bodge it and scarper.hahahaha ah

 

[MattJago]

I'm waiting for quotes from 3 local plumbers, but thought I'd update to say the same sound happened after this morning's shower. I went in the roof and when depressing the float in the main tank, the sound did stop (thanks, Pete!) however as soon as I stopped pressing it, the sound returned instantly. I tried going back to my original fix of doing the same in the extension tank, but again the sound and vibrations only stopped when the float was pushed down.

6/7 minutes later it stopped without me doing anything else.

I'll try and get a plumber out this week, but is this something that potentially could become a bigger issue if left? Worst fears would be a leak or similar - could this cause one? The house was built in 1994 and as far as I am aware (the last owner couldn't tell too much) the plumbing is original.

 

[AGAS]

i wouldn't waste your time getting 3 quotes to change a ball valve , it won't cost much . but thats my opinion

 

[DaveHerns]

I got a water meter fitted and my plumbing started making a noise. A new ball valve on the main tank cured it. I think a new washer would have been enough as it was a bit scaly. Is that within your plumbing capabilities for a cheap and easy fix?