When I empty my upstairs bath my downstairs toilet fills up. Does anyone know why?

Al, December 2008

I would at a guess say the ONLY way thats going to happen is is your soil pipe / drains are blocked - The bath waste usually goes into the soilpipe stack and the i assume the downstairs loo you have is below - therefore the water from your bath is faslling into the same soilpipe but not flowing away as it should!!! I would get pipe checked or cleared before u have a downstairs loo full of nasties!!! Hope this helps even IF not reassuring

Peter - (Jack of all trades master of none), December 2008

pipe blockage somewhere after downstairs loo

glen, December 2008

I have had similar problems. A partially blocked inspection pit outflow - caused the water level to rise in the pit. A sudden inflow from an upstairs bath increases the air pressure in the pit and this forces water back into the house - the pit slowly drains through the partial blockage.

Find the inspection pit cover. Old clothes - rubber gloves - hosepipe and a poking stick. Ten minutes poking around and another ten clearing up. Sort of job best done as soon as you notice it - less foul water in the pit.

Peccavi, December 2008