Air Admittance Valves

MikePro

Member
I have a 2013 Heartland Prowler 32P BHS and am getting a sewer smell in the trailer when running my a/c. It has been hot and humid here lately so we have been running the a/c on high. Reading on the internet leads me to suspect the valve/s needs cleaning or replacing. Does anyone know how many of these valves my trailer would have? I have a double sink in the kitchen, a tub/shower and a sink in the bathroom, and a sink in the outdoor bar enclosure. Thanks
 

Hollandt

Well-known member
I have a 2013 Heartland Prowler 32P BHS and am getting a sewer smell in the trailer when running my a/c. It has been hot and humid here lately so we have been running the a/c on high. Reading on the internet leads me to suspect the valve/s needs cleaning or replacing. Does anyone know how many of these valves my trailer would have? I have a double sink in the kitchen, a tub/shower and a sink in the bathroom, and a sink in the outdoor bar enclosure. Thanks
Typically each sink and/or vent may have one.
 

MikePro

Member
Thanks folks. Heading out today to look. If there is one on each sink would the shower/tub not have one as well?
 

SLO

Well-known member
Air admittance valves should only be used when there is no way to vent out the roof. Like a island kitchen sink. Trailer manufacturers don’t have to follow the same codes as regular home though so you may have air admittance valves (studor or valve) on other fixtures. Vents are only there to keep the trap from siphoning out (it prevents the vacuum) and the trap is only there to keep sewer gases from coming out your drain.
 
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MikePro

Member
So I went to the trailer Friday after supper and at first, no smell, Turned on the a/c and went about doing other things. Maybe 3 hours later the trailer started to smell so I started looking for the aav's. There is one under the kitchen sink and there was no smell there. Found the second valve under the bathroom sink and when I opened the vanity door it reeked and really stunk up the place. (Could only find the 2 aav's as the line from the bar area sink goes directly into the bathroom.) So I removed that valve and taped a ziploc bag over the pipe. Next morning the smell was still there but not as strong. So I went up on the roof to check the vent pipes. Only checked two of three pipes before I had to leave but both were cut short to barely above the roof line. The second one actually had a gap around it big enough that I could see into the ceiling cavity so it defenitley had to be letting fumes into the trailer ceiling space. Back in town I got two aav's at Lowes, unfortunately they were cheap and are similar to the ones I am replacing. They had other more expensive ones, Oatey Sure Vents, but they were all for 2 inch pipe and there was no way to reduce them. I was hoping to get either a Studor or Oatey. I also picked up some pipe connectors to extend my vent pipes and some spray foam to fill the gaps between the pipes and ceiling cavity. I hope this solves my stink problem.
 
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