I have an en-suite on the ground floor with a shower waste connected into a 2" cast iron waste which drains an upstairs bath and sink.
The problem is that when the bath upstairs drains it pushes foul air back up through the shower waste.
I have checked for blockages and everything seems alright.
Any thoughts on how to resolve it would be most appreciated.
The problem is that when the bath upstairs drains it pushes foul air back up through the shower waste.
I have checked for blockages and everything seems alright.
Any thoughts on how to resolve it would be most appreciated.