Hoping that someone might be able to give me some advice...
Everytime I flush my upstairs ensuite toilet or run water into the wash basin, I get a really horrible sewage smell downstairs in my kitchen which seems to waft up via the kitchen sink plug holes (I think!?) It's only just started happening and seems to be since my Dad replaced part of the waste pipe behind my dishwasher. I had a leak where the waste pipe from the dishwasher connected to the main waste pipe. My Dad resolved it by cutting out part of the main waste pipe and replaced it with what looks like a big upside down 'T' pipe with the dishwasher waste pipe feeding down into it (hopefully someone understands my description!). I wonder if this is a contributing factor and if anyone could advise how this could be resolved? The waste pipe from my washing machine is set up in the same way and it's never caused this problem so I'm a bit confused! :?
It may help to know that the toilet upstairs has a macerator unit.
Anyone who has any advice, please let me know. It will be gratefully received.