I know about the AA valves inside but ...

[Happy Campers]

Lets talk about on the roof.Somebody recently told me that I have the Air Admittance Valves attached to the vent pipes on top of my RV.It's been a long time since i've been able to get on my roof but I don't remember them up there.Can somebody shed some light on this for me.I think it is just open vented to the atmosphere.
Thank you.

 

[danemayer]

Air admittance valves, where installed, are usually under the sinks near the p-traps.

 

[Happy Campers]

I have seen the Air admittance valves underneath the sinks but is there anything at all on the vent pipes on the roof ?.

 

[jmgratz]

I have seen the Air admittance valves underneath the sinks but is there anything at all on the vent pipes on the roof ?.

The only thing on the rood is a cap to cover the vent pipe.

 

[Bob&Patty]

I thought there was one the vent the roof/attic.