whats happening to cause my bath waste to leak.

[capnahab]

Bath has a central plug hole with a pipe to wall and waste. Out of the blue it has started leaking from a joint downstream to the waste , - see green arrow in photo. It happens when unplugging the bath to drain for about 30 seconds and then stops. Could have been hit by vacuum cleaner recently....

 

[Masood]

That's an anti-siphon valve which helps prevent gurgling noises and also helps effective draining. It's probably stuck in the open position. You may be able to free it up. If you look into the opening you'll see a spindle. Try moving that up & down a bit. If not, they are not expensive to replace.

 

[Chalked]

Hi
As post above :stupid::stupid:

But looking how low it is installed, it's probably blocked. Causing water to back up.