Odd noise when flushing

nibs

Looks like this is my annual discussion.
Am staying at an Air B&B in England and there is an odd noise when flushing.
It sounds very much like a diaphragm pump while the tank is filling, and the vibration is strong enough to open the hot valve in the adjacent sink. I think that there is some sort of harmonic going on, & would love to tell our host. Was thinking that a small expansion chamber in the copper hot pipe to the sink would cure it.
I understand that this would be a band aid but would be quick and affordable. We are moving on Monday morning, t'would be a nice thing to be able to help a little.
Tony.

Jamie Hall

Odd. But I don't think an expansion tank would help. Keep in mind that UK plumbing operates on far lower pressure than North American -- and that there shouldn't be a connection between the loo fill pipe and a hot water pipe anyway.

hot_rod

Is it a pressure assist toilet? Open the tank lid, is there a large plastic tank inside. These could be noisy, vibration, chatter, squealing.

Or a loose disc on the toilet ballcock fluttering around.

mattmia2

I know in some places the mains are very low pressure and houses have a cistern that is filled slowly from the main. There might be a pump involved in filling or emptying the cistern.

JDHW

In the uk it is not permitted to directly install a pump on the incoming main. Could be a cistern and pump as @mattmia2 suggested. What about a rainwater recovery system to the toilet?