Plumbing

Intermittent bad smell from toilet

Anonymous user 23/02/2024 - 3.49 PM

Hi all We've been experiencing an intermittent smell from our downstairs toilet for the last few months. We've tried replacing the pan connector and have had a CCTV inspection on the drain, but the problem persists. Last week I removed the toilet again and disconnected the sink trap. Both have been capped but we're still getting the smell. The soil stack is boxed in with no access on the ground floor. It's partly visible through a gap in the skirting and plasterboard that surrounds the pan connector. Everything is covered in dust and there are no signs of leaks. The soil stack also services our bathroom and toilet on the first floor. It is boxed in here too, but there is a large gap behind our vanity unit. Despite this, we've never experienced a smell in this room. The stack isn't vented externally, so, I assume it's capped internally. Here's a diagram of our system. We have a separate vented stack that serves the en-suite. Everything converges in a manhole and the two stacks aren't connected: https://ibb.co/ZmkpzR5. For reference, the house was built in 2017. Any ideas? Thanks in advance for your help.