Humming noise - pipe work, or the isolation valves?

[Joseph83]

Hi,

Just moved into a 4 bed house which has had 2 bedrooms extended. The 2 extended rooms had en-suites fitted, they sit back to back with 'mirrored' layouts on either side of the wall (toilet opposite toilet, sink opposite sink, etc) so I guessed they are fed by the same pipe, and I have found one single pipe going up to the extension that gets cold when either of the ensuite toilets/cold taps are used.

Each has a toilet, basin and mixer shower. All of this was done before we bought the house.

In the ensuites, if you flush the toilet in ensuite 1 or 2, or run the cold tap in ensuite 1 only, there is a loud vibration/humming noise through the pipe. cold tap in ensuite 2 is fine. Both showers are fine.

The original bathroom doesn't suffer from any of this at all.

All toilets and all taps have isolation valves. Turning them down on the problem items changes the noise, but doesn't cure it.

Turning down the house stopcock reduces it a bit, but then the showers are not very powerful.

I've changed the toilet fill valves - no difference. It even did it when I disconnected the fill valve and accidentally turned the water on again and water was just spraying out of the pipe!

I thought it might be the pipe is loose, but if thats the case why is 1 tap perfectly silent? Exact same make of tap in both ensuites.

Got me thinking if the isolation valves are the problem. I'm no expert by a long way but I read that they can make the vibrations if there is debris or they don't flow 100%.

What do the experts think?

 

[plastic_peanut]

I’m no expert but is it worth looking at a water hammer arrester?

 

[CBW]

Could be the tap itself.

 

[ReJect]

As there is isolating valves to the taps, - why not turn each tap iso valve off, one at a time and that will prove if a tap has a fault? Some cartridges can cause a buzzing/vibrating noise when they become loose inside.

 

[Joseph83]

The problem is in one tap AND two toilets so the tap isn't the source, just a symptom.

 

[Dangee]

It's probably from a shower valve believe it or not. It sounds like a check valve letting by & back feeding causing vibration. I presume it's an unvented cylinder?

 

[CBW]

The problem is in one tap AND two toilets so the tap isn't the source, just a symptom.

Could be the iso valves, could be unclipped pipework, and as @ReJect could be a cartridge not even related to the extension I’ve had customers tell me the boiler makes a noise when a tap is ran, only to find a dripping ceramic cartridge upstairs or vice versa.

 

[ReJect]

The problem is in one tap AND two toilets so the tap isn't the source, just a symptom.

Just don’t assume that. It can be in one tap somewhere in your home, unrelated to where you use water. Just isolate each tap to rule them out, as will only take a few minutes to do so.
Water hammer is a strange thing.

 

[Dangee]

As I say, probably non return valves on a shower.