Iâ€™ve just installed a new bathroom but when emptying the bath or the sink the shower trap gurgles. The water in the trap also moves when the toilet is flushed but it does not gurgle.
Iâ€™ve read the DIY project on â€˜Gurgling basinsâ€™. Can I install an air admittance valve on the pipe leading to the shower trap? The only problem is that the air vent will be at the same level as the shower trap, will this still work? Or would it be better to install this under the sink which is the highest point?
Sometimes the bath gurgles too; do I need to install an air vent on the bath too?
The sink has an anti-vac bottle trap. The waste pipes are all 40mm apart from the last meter up to the sink which is 32mm.
The old bathroom did not have a shower but the bath was (and is) slow in draining
Thanks for your help