I have a loft conversion with a shower. Unfortunately the waste water
doesn't drain from the shower tray unless I use a plunger. I only have to
plunge once and the water drains away. This could be due to poor design.
The waste pipe is approx. 5 - 6 meters with 2 bends and very little
gradiant before it joins the soil stack. Would it be feasable to put a
water pump somewhere along the waste pipe and then have a waterproof
switch near the shower to turn it on. The waste pipe is 43mm which is not
standard and the gradiant can not be changed. I have looked at water
pumps and can't find anything suitable. Any ideas would be greatly
appreciated.

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