I have fitted a new pan with concealed cistern, the trap which has plenty of water in it, feeds into a 90 degree bend travel in a soil pipe with a good fall about 1/2 a meter into the vertical soil stack which vents in my loft.
I have put bleach, cleaning blocks you name it in the cistern without any long term effect.
The smell seems worse on windy days??
I have put bleach, cleaning blocks you name it in the cistern without any long term effect.
The smell seems worse on windy days??
at best it will have an Air Admittance Valve ( Durgo) at worst it will be just an open pipe 
. I just don`t like them and would have the pipe venting to air . However the problem is probably coming from the other sani. appliances in the bathroom - the traps are being pulled by the wind / poor pipe design.
