Smelling Toilet Drainage and wastage systems and plumbing help, advice and answers

[Bob Bridger]

Hi,When I flush my toilet the water level goes down below normal level, thus allowing an Air Passage which then permits bad air to pass back into atmosphere of the toilet which continually creates bad odour. The toilet is a Heritage Manufactutr and is approx.5 years old. What can you suggest as a suitable remedy ,I am more than capable of carrying out any suggestion you might offer.
Thanks in anticipation

[rosebery]

As the output from the toilet descends the soil pipe it is creating a vacuum above it. That in turn is creating syphonage which is sucking the water out of the trap in the toilet thus allowing the bad smells into the building.

So that says the dry (vent) element of the soil stack isn't working properly.

It has got an open to atmosphere vent I suppose or does it have an Air Admittance Valve? In either case you need to check out why air is not being allowed to enter the system when the toilet is flushed.

Cheers

[collectors]

If its been working fine in the past, it sounds like the water being flushed is acting like a suction pump & pulling the remaining water out of the toilet water trap. This would point to either the pipe that go's to above the roof is some how blocked. Or! you may have fitted what is called a "dergo valve" . This is a unit that fits on an up stand of 100mm pipe next to to WC & allows air into the pipe when flushed & closes automaticly when the flush has finished leaving water in the wc to stop smells. This dergo unit looks a little like a blanking off plug for the end of the pipe.
Some help here.
[url]https://www.diydoctor.org.uk/projects/air_admittance_valves.htm[/url]