"Bod" wrote in message
...
On 07/05/2015 08:04, Jim GM4DHJ ... wrote:
"Bod" wrote in message
...
On 07/05/2015 07:49, Jim GM4DHJ ... wrote:
Why do people insist on fitting air admittance valves outside? ... are
they
mad?...you see them everywhere...!


They look much better than having a long 4" vent pipe going all the way
up
and 2ft above gutters.

what if they freeze up?...I know it is unlikely due to hot air in the
system
.......I'll have to have another look at fitting instructions .....


I'm a retired plumber and I cannot recall any durgo valve freezing.


must be the reason why you cant fit outside...I recall if fitting inside a
building they had to be below the roof insulation level ????