In our recently fitted shower we have in the last few days had an issue with the shower tray filling up and not draining. Checking the trap has found no debris and the problem soon rights itself with a few glugs and air bubbles and continues to drain as normal.
The tray is sitting on a suspended wood floor at ground level. A 40mm waste is attached to an adjacent 4” joist that runs for about 2m with a fall from just under the floor boards to under the joist. It then takes a bend and a short run of about 500mm which is almost level before entering the stack.
Tee’d into the short section is a further 40mm pipe coming in vertically that drains the boiler condensate and the boiler PRV. On part of the horizontal section from the boiler is an inline U- bend.
Finally, a 32mm waste pipe is Tee’d from the hand basin into the vertical section with approx. 1.2m of generously angled pipe.
I cannot considering the recent installation of this pipework think there is a blockage and that the glugging and release of air bubbles and the self correction to me suggests that something is airlocking especially when the shower is on full pelt.
So the question is will an Air admittance valve in the system solve the issue?