Whisteling pipes when tap used and/or toilet flushed...

[Susanne]

I have a problem with noise in our bathroom (worse at night), I have no plumbing knowledge, but will try to describe it as clearly as I can:

Typical, terraced London townhouse. We've had the house for 8 years, the following problem is fairly recent.

1)
When the toilet is flushed, the refilling sounds quite laboured, a big "engine" noise starts up under floorlevel. In the nighttime there is an added "dunka dunka dunka"-sound until the cistern is full.
This is all noticeable through the whole house.

2)
During nighttime only, after flushing the toilet, or sometimes using the handbasin tap, there are loud whisteling noises from the pipes under the floor. During and after this, there is also a sound of rushing water in the pipes, with frequent, intermittent "clonk"s, as if someone were turning taps on and off somewhere else.
I can stop these sounds by turning the taps in the handbasin on, but the noise resumes when I turn the tap off again.
The noises go on for a while, a bit longer than it takes the cistern to fill up during daytime.

Any advice on how to fix this problem?
Is it something to do with lower waterpressure during the night?
There is no spluttering when we turn the taps on.

Thanks!

 

[Nige F]

Is it something to do with lower waterpressure during the night?
Thanks!

Higher pressure - just fit a new washer to the float valve in the WC - for starters

 

[Susanne]

Thanks - the toilet is not that old (about 3-4 years), does it still need to have the washer replaced?

I've been Googling to see how to replace such a washer, and have now worked out how to shut off the water supply, in order to have a good look at the bits in my, thankfully, bright and clean looking cistern.

My float arm has 2 places where I can screw it apart, first one is where the moveable float-arm is attached, the second place is half way down the tube.

I assumed that the washer I need to check is the second one, but I cannot get to it, it's casing is screwed together tightly. My hand strength is low.

But looking at this, it got me wondering how replacing a washer will help with the noise problem? The cistern fills up quickly, after all.

However, the main question is: Do I really need to replace a washer that's not really that old?

If yes, I will have another go at taking the parts apart.

Thanks again.