Thanks Hugh- attached with flow directions.
The plumber added the non return valve as the bath water was draining and then popping up under shower. That said, even with this is in place that still happens!!
So - photos of pipe work. And then videos of bathroom with good flow and one with bad flow.
A lot of gurgling noises in pipes whether trying to drain bath, shower or sink, and bath backs up into and comes out of shower drain when try to empty it.
I'll drop a video of flow of water in bathroom with issues and flow in bathroom that runs to same waste stack.
And a photo of pipework from when had the ceiling down...
It's not good in terms of fall (goes through beams and marginal drop). However, the pipes form the other bathroom run into same pipe and they drain super swiftly!
Thanks for responding.
Have had ceiling down and plumber in and no blockages at all I’m afraid, so it isn’t that. Wet vac brought nothing back, and camera shows pipes completely clear, so think it must be something else other than a blockage.
I have a shower, bath and basin that all drain slowly, and the bath emptying now results in water coming up through shower trap. A lot of gurgling noises too. The shower trap does not empty quickly enough and will overflow over the shower tray if take a shower over a couple of minutes.
I have...