toilet smell downstairs cloakroom, please HELP!

[chezy24]

Hi

I have a downstairs cloakroom with a toilet and sink which smells offensive. It has been like this on/off for 4 years. I have always cleaned and cleaned with no avail so last week bit the bullet and got a plumber to redo the soil pipes as it had been done by previous owners and looked a bit of a mess (although boxed in). Plumber did it, found a spilt seal in the pipe going into the ground, great sorted I thought, 2 days no smell then it returned!!!!! ARG!!!. The smell appears to come from inside the toilet pan/water so i covered/cling filmed the toilet and smell went, then returned and appears to be coming from the cistern? it is a back to the wall toilet and cistern. The toilet is below our ensuite (and the soil stack is also used for the ensuite). Please anyone any suggestions???. Ive called the plumber, just waiting for him to get back to me.

Thankyou in advance for any suggestions!!!

 

[Unklian]

I'm not a plumber but was just wondering......
When you flush the en-suite toilet, does it make the water in the downstairs (smelly) loo drop?

Possibly, If flushing the upstairs loo makes the downstairs drain syphon / suck water into the drain, it may lower the level in the "U" bend just enough for the foul air to get past.

Ian.

 

[chezy24]

Have'nt looked at water levels, I shall try it and see what happens. If that does happen what would that mean? Thanx

 

[Unklian]

The pupose of all "U" bends is to fill with water.
Under your sink, bottom of the toilet etc.
The "U" fills with water and forms a seal so that smelly air from the drains doesn't blow into your house.

If by your configuration of drains, the water is being sucked out of the downstairs loo by prhaps a couple of inches, there won't be enough
water left to fill the "U" and seal out and drain smells.

Flush your upstairs loo,
go downstairs and look at the water level.
Now flush the downstairs loo.
If the water level is now a lot higher, this may be your problem.

Only just a layman's guess though. (My washing machine used to do this to the kitchen sink drain).

I suppose you could also test by not using the upstairs loo for a couple of days
and only using the downstairs. The "U" should always remain full, blocking off foul air.

Ian.