Odor in bedroom and bathroom area. - Montana Owners Club

thundercat · 08-24-2005, 09:48 AM

Can any one explain why Keystone would install a vent pipe from the gray water tank up under the bathroom sink. We get a lot of nasty odor from this. I took a plastic bag and ty-raped it over the vent and cut down on the odor quite a bit but can't for the life of me figure out why you would vent a holding tank inside of the camper. This doesn't even make bad sense never mind good sense. If they needed another vent for the lavatory sink trap the least they could do is install a wall vent to the outside. If anyone could shed any light on this I sure would be interested in the justification.

Bill and Ann · 08-24-2005, 09:54 AM

Our unit has a vent pipe to the roof from all three tanks. Don't have a problem since we put on one on the rotating vent thingies on the roof vent for the black. Going to do the same to the other two.

ronstan · 08-24-2005, 10:00 AM

I'm not sure what the problem is but I don't think you should be getting a smell under the sink. I know there has been postings on here about what that vent is but I can't remember now. Someone will be along who knows.

CountryGuy · 08-24-2005, 10:52 AM

I think they have been vented like that for years. Maybe there is a code????

Bill, we tried to put that rotating vent thing on, but it hit the TV antenna. We were very sad! SIGH

Ishler · 08-24-2005, 12:06 PM

Usually that is a vacuum break for the sink and has a one-way vent on it. The tank is vented out side. If the pipe under the sink doesn't have a fitting and a "gadget" on the end then that's the source of the oder. If it has the gadget, then the valve in it is stuck or defective. The local home improvment stores usually have a replacement (it screws in) It should let air in the pipe but not back out.

tundra rose · 08-24-2005, 08:29 PM

The vacuum break backflow preventer for the black water tank flushing system is located in the bathroom sink cabinet in our 2955RL. It has two water lines attached to it - one at the bottom and one on the side of the unit. There is a spring-loaded check valve in the outlet(side port) of the unit. If this describes the unit that is allowing odors into your bathroom, the check valve is most likely blocked open with debris. You may be able to clear it; however, you may need to replace it.
An easy way to check the unit is to unfasten the backflow preventer from the two water lines, remove the shower head from the hose and then attach the unit to the hose and run water thru it. You should have water flow from the bottom port through the side port. If you have water flow from the side port to the bottom port, the check valve is definitely blocked open.

thundercat · 08-25-2005, 01:59 AM

I called Lee's Family Trailer Sales where I bought the unit and they said that it is a vacuum breaker for the drain line. If you get odor from it then the unit is either stuck or defective and needs to be replaced. In order to replace this unit you have to pull the sink out to unscrew the vacuum breaker. As a clarification this unit is located in the 1-1/2" black drain line and is not part of the black water flush system. So it looks like I get to pull the sink and replace the original. Thanks for the reply's.

jerryb · 08-25-2005, 02:28 PM

All the sinks and I think the toilet have them, mobile homes do also. There is just a little flapper in there that could stick. There is a vacuum break for the black water flush under the lav. also, that some times leaks a little water when flushing the black tank.

bob n pam · 08-25-2005, 03:20 PM

I've always wondered what that was under the sink. Thanks!!

sreigle · 08-26-2005, 08:05 PM

Thundercat, I've not had to pull ours out but several here have posted about replacing the valve and I don't recall any of them mentioning having to pull out the sink. Might be worth taking a hard look before taking out the sink.

thundercat · 08-31-2005, 06:28 AM

I bought a new vacuum break fitting for $1.99 at a local camping place and replaced the existing one. I could get the old one out without removing the sink but the new one was a 1/4" longer so I had to remove the sink to install it. The new one has a stainless steel spring in it for an actuator where the old one was just a rubber flapper. I hope that this will cure the odor problems. Happy trails.

jerryb · 09-01-2005, 03:18 PM

I had to put a new sink trap in the stick house so went to Lowes. They have plumbing parts for mobile homes which might fit R.V's. Even the p trap was different from the stick house, if I remember right the one for the mobile was bigger.

You may also like: