Smelly downstairs toilet

MattyJ80

Hello. 

We have started to get an intermittent smell from our downstairs toilet.

We have a septic tank with a shared outlet pipe with other houses in the row, all built around 1860, and an en-suite shower room upstairs that has an external vent pipe with the waste running under the house to a chamber where the downstairs toilet waste then joins it and runs into the 2 chamber brick septic tank. The downstairs bath and sink both run into an open gulley drain and then into the tank.
The traps in the sink, bath and toilet pan downstairs have water in them, but is it possible water running into the tank from the en-suite shower could create air pressure to force smells back up into the downstairs bathroom via the toilet?
There is no sign of any leaks or gas bubbles when using the ensuite. Is it possible for gas to escape from the toilet but not water?

We could replace the toilet although due to the location of the underground water pipe to the kitchen it would have to be concreted in rather than screwed to the floor. The existing toilet is the same, maybe thats the issue if it has rocked slightly and cracked?

Any advice gratefully received as its driving us nuts! 

neilmcl

How often do you use the downstairs toilet. Mine on occasion gets the same sort of sewage smell if it's not been flushed in a while, in fact it was only this week that I spent a Monday morning throwing loads of bleach down it and re-flushing it. It now smells fine.

MattyJ80

It gets used everyday. It seems to be random when it smells or doesn't

ic

Random after a certain user?

georgehere

Check the fit of the toilet outlet to the flexible connector (that then goes down to to the drain).

Rocking or age of the flex connector can eventually cause air leakage where the toilet goes into the connector. Before going off and replacing the connector try sealing around with silicone sealant. If that works then you can go further.

Or just leave well alone.

fenwick458

how hot is it? I do jobs at a B&B where they have a biomass boiler and in order to make it pay they have the thing running flat out all year round, so all the water just evaporates from the traps and u bends and lets sewer gas straight into the bathrooms

Rosa_Damascena

neilmcl said:

How often do you use the downstairs toilet. Mine on occasion gets the same sort of sewage smell if it's not been flushed in a while, in fact it was only this week that I spent a Monday morning throwing loads of bleach down it and re-flushing it. It now smells fine.

But this is a temporary fix only. Aren't you interested in a permanent solution? Good sanitation systems do not smell.

Emmia

We had a sewage/gas smell emitting from our shower drain that used to wake me up at night.

...despite lots of drain cleaner, Jeyes fluid, bleach etc., which fixed the whiff short term...  it turned out the drain was pretty blocked and needed descaling - it eventually stopped draining and backed up with raw sewage - 2 visits from a drain company later, and the removal of lumps of scale the size of a forearm it's working great and no whiffs.