In article ,
"JoeJoe" writes:
The waste run in my new kitchen is very long, and hence the BCO insisted on
installing an AAV on the 40mm pipe. The plan is to fit it under the worktop
next to the kitchen sink.

My logic suggests that the AAV needs to be fitted above the highest possible
water level in the sink. IS this really the case? i.e. do I need to re-think
my plan?

I don't think that's the case for a 40mm waste run.
They are commonly integral with the U-trap, which
will always be lower than the sink.

--
Andrew Gabriel