Problem with Internal Soil Stack Vent and Toilet and Bath Gurgling Drainage and wastage systems and plumbing help, advice and answers

[gemjams]

Hello,

I've been having problems with the downstairs bathroom. Every time the toilet is flushed the bath plug gurgles and water splutters out and vice versa when the bath is drained the toilet gurgles.There is also a sewage smell in the house but it doesn't appear to be coming from the bathroom.

I found the internal soil stack vent also made a whirring noise when this happened so did a bit of an investigation. The top of the vent came off very easily and I found that if I pushed down on the spring (I think it's the air admittance valve?) the toilet flushed no problem.

My question is (or are), is this the cause of the problem or just a symptom? Can I just put a weight on top of the valve so it's always pushed down or will this cause problems?

[lets have a look]

sounds like you need a air admittance valve,it works on the same principal as sucking water up a straw and holding your finger over the top,release your finger and the water comes out,but with a soilpipe being much bigger it tries to suck air in,hence the noise,the AAV stops any smell coming out by closing when no water is drained and opens when you drain water,

it usually sucks water from a trap (u bend) that is the gurgling you hear and leaves the trap empty allowing smells to come up.