Grey Tank Odor

bad99ram wrote:
I have a 2013 Jayco Premier 351MKTS. I am having a problem with a strong sewer gas type odor coming into the unit when I use the Bathroom fan or Fantastic fan. Both fans are set on exhaust. It is most noticeable under the Kitchen sink , but sometimes comes out from underneath the bathroom sink. Both air admittance valves under the sinks have been replaced and the vent thru the roof has been checked and is clear of obstructions. Does anyone have any ideas what else to check ? Its at the dealership now and the service manager has verified that there is a problem but thus far has not found a solution.

I have a similar problem, the issue is that the rv manufactuers have little idea how things work. What you have I belive from reading your post is valves ment to alow your tank to drain installed under your sinks. This is used in houses and even buildings sometimes and generaly are called studer vents. They are similar to a check valave and are designed to allow air to go into the pipe and check to prevent the tank from venting. This works fine on standard plumbing but when you have what we have and you fill a tank by draining a sink you are displacing the air with water and actually presurising the tank. These valaves are not made to hold back presure so when you drain your sink the tank burps air out of the valave and under your sink. Sadly the only thing you can do is either flush the tank well and often to keep odors out or vent the pipe to the outside. The valaves are not bad just miss applied.

I know sucks don't it. Seems like someone who builds rvs would have figured this out by now. I have one set up like this also. still thinking about the best way to permantly fix it.