I have a problem with improving the rate at which our newly installed
bath drains. The old one was just as bad, the difficulty is the poor
design of the original installation which I am rather stuck with.


If the old one was as bad, you might have grease in the pipework
making it worse (causetic soda and caution) or a mchanical partial
block (bendy springy thing)

I didnt follow the setup entirely, but can you parallel your 2 waste
pipes? If you can that would speed it up to some extent.

Finally pumped waste is simple enough, but AFAIK you'd have to either
make the sensor and control circuit yourself, or else just use a
manually operated switch for the pump, preferably a push switch with
built in timer, as used in communal hallways etc.


Regards, NT