Bath drain noise

[GeoH]

We installed a new bathroom suite 18 months ago.
Recently in the last 3-4 months we have started to get a noise from the bath drain when any other water is run in the other basins / sinks within the house
The bathroom is located upstairs and the noise happens when the upstairs wash hand basin is used and also when the down stairs sink is used as well.

Any ideas or cause and a fix

Ta

George

 

[LUNAT]

HI

drain pipes incorrect size or too many appliances fitted to the waste pipe to overcome this( if possible) bath waste pipe 40mm straight to the soil pipe
it is also better if all appliances have separate waste pipes connecting the soil pipe

 

[manortim]

whats happening is the pipes are becoming more and more blocked up, this causes a venturi effect, where by the water is going so fast the other side of the blockage, its sucking on the trap in the bath.

either put some decent drain cleaning down the plugs, i.e ONE SHOT or the sort, that you'd only get from plumbers merchants, OR if that doesn't quite sort it, change the trap on the basin to one with a air attmitance valve on it.