My friends have had an extension with new bathroom. All has been fine for the 4 months. Now, flushing nearly fills the bowl, then seeps away slowly; water back flows up into sink. They have a Durgo AAV (which was boxed in). After trial an error the buidler/plumber chap changed the valve - same problem. But they noticed that with no valve on at all, all was well. Put it back on, problem comes back.
Seems "obvious" that the valve, and its replacement, were both faulty. Am I missing something else?
I have read that even with a Durgo, the system needs to be vented. Is that so, and if so, why? My friends dont believe theirs is.
Seems "obvious" that the valve, and its replacement, were both faulty. Am I missing something else?
I have read that even with a Durgo, the system needs to be vented. Is that so, and if so, why? My friends dont believe theirs is.