In message ,
Keefiedee writes
On Sunday, 24 March 2019 08:08:13 UTC, PeterC wrote:
On Sat, 23 Mar 2019 13:07:58 -0700 (PDT), Keefiedee wrote:

We have a problem with a drain smell in our cloakroom, which is
fitted with a shower. I realise that it is possible to fit a
non-return valve to the outflow, but access would be very difficult.
came across an Australian non-return valve which might fit in the
shower drain:

https://www.youtube.com/watch?v=P1bbwCyHyn4

And I also found "floor drain duckbill check valves" - but no
associated web page.

Has anyone come across these, or anything similar?

There are three that work on the same principle:
https://mcalpineplumbing.com/traps/s...g-waste-valves
https://www.vivasanitary.co.uk/products/traps.aspx third row down.
https://hepvo.com/

Toolstation has Macvalve and Viva Magna:
https://www.toolstation.com/plumbing/wastes/c981?
--
Peter.
The gods will stay away
whilst religions hold sway

Many thanks. My problem with that type of fitting is lack of access -
which is why I wondered about the Australian non-return valve.

To answer other points made - I don't think the trap is defective, it's
not very old, but it definitely isn't used much. But it has always
been slightly smelly - and my wife has a very delicate nose!

Recent high winds may have emptied water traps with the venturi effect
sucking air from the stack vent. Not noticed with toilets/wash basins in
regular use.

--
Tim Lamb