HueyPilotVNHueyPilotVN said:Maybe the roof vent opening from your black water tank is close to the roof air conditioner.
They do make a swiveling vent outlet called a Venturi and the air passing by creates a suction but the wind might still be blowing the wrong way.
Have been dealing with this ever since I bought my 1999 rv. Anytime I flush or drain sewer my ac blows in the nastiest sewer smell in the world. I’ve just dealt with it. But I’m so sick of it. I can go outside on the top and I don’t smell anything. Come back into my room and almost vomit for the thick smell. My 22 year old son can not figure it out. Everyone says it only recirculates the air in the rv. This is absolutly not true. My room did not stink before. The second you flush or pull the drain sewer it’s like it’s draining into my room. I don’t know what to do. I’m ready to trade it in. For a new one. I wish I knew the drain diagram or how the ac hooked up. Bu something somewhere is leaking sewer and I have talked to repair centers and they don’t help at all.The line about A/C's sucking in odors or fumes from rooftop.. Does not happen. A/C air is all recirculated. What is inside is inside what is outside is outside.
Exception: some older units DID have optional fresh air intake or exhaust (Dampers before and after the blower that you could open or close with a control) but nothing I'm aware of made this century.
Have you ever taken your inside AC components off your ceiling, and had a look at your ducts?Have been dealing with this ever since I bought my 1999 rv. Anytime I flush or drain sewer my ac blows in the nastiest sewer smell in the world. I’ve just dealt with it. But I’m so sick of it. I can go outside on the top and I don’t smell anything. Come back into my room and almost vomit for the thick smell. My 22 year old son can not figure it out. Everyone says it only recirculates the air in the rv. This is absolutly not true. My room did not stink before. The second you flush or pull the drain sewer it’s like it’s draining into my room. I don’t know what to do. I’m ready to trade it in. For a new one. I wish I knew the drain diagram or how the ac hooked up. Bu something somewhere is leaking sewer and I have talked to repair centers and they don’t help at all.
The AC does not pull air from the outside - as others have stated. So wondering why you state that is absolutely not true?Everyone says it only recirculates the air in the rv. This is absolutly not true. My room did not stink before. The second you flush or pull the drain sewer it’s like it’s draining into my room.
Last weekend, someone's fire smoke was trickling right over my AC unit and it sure did smell up my trailer.The AC does not pull air from the outside - as others have stated. So wondering why you state that is absolutely not true?
RVs are not air tight, so although the A/C itself may not be bringing in outside air, there are many other ways for such smells to get inside. Once a little gets in, the A/C tends to endlessly recirculate it.Last weekend, someone's fire smoke was trickling right over my AC unit and it sure did smell up my trailer.
Because it is a waste of money. Pure water works best.In the short run, get an enzymatic black tank odor control chemical that will better break down the waste. Yes, yes, posters, many of you are vehemently opposed to this ( I don't understand why), but I swear by my Thetford treatment and won't go without it.
Sir. I am so sorry. I was thinking about something else when I typed that date. It’s actually a 2019 forest river sandpiper 370flok. I bought it brand new from the factory. I had it custom build. Took them about a month and a half and then had it shipped to me here in Texas. But last night I watched several YouTube videos about installing new units and I have a really good idea how it all works now. So I’m planning on next week pulling the unit and looking all around where it was mounted. I have a big ac vent about 3 feet alway from the ac in the ceiling. I’m betting there is something going on there in that space. But I’m going to seal it up real good and hopefully that fixes it. If not then my next course of action it to remove the vent on the roof and add another pipe about 10 feet in the air for venting. The current sewer vent is about a foot and a half from my ac unit. So after I seal the ac really well and raise the sewer vent a little higher I should definitely not have anymore sewer smell in my bedroom. Lol.Have you ever taken your inside AC components off your ceiling, and had a look at your ducts?
I'll bet I could fix your problem in a one day review and repair.
How long have you had your 1999 unit?
As I've written in other threads, RV's are mostly constructed with garbage quality care. My AC had the wrong framing piece in the duct work because a lazy worker couldn't be bothered to walk over and get the correct piece. He/she used a framing piece made for the one side that actually routes the air to the main duct. To clarify: That framing piece had the oval cutout intended for attaching ducting. The result was that cold air was being blown into my insulation between my ceiling and roof. It rained in my RV!!! As soon as I covered that cutout and correctly insulated all returns, my problem was solved. The actual duct routing piece was attached, poorly, to my main duct. It is well insulated, and attached properly, now.
I'll bet your ducting and AC framing is a joke, and that your vent pipe has a bad connection in your wall. THAT would be the best explanation for what you're experiencing. You may have to open your wall to check your vent pipe, but don't go there until you check all of your duct work and main AC framing in the ceiling.
Good luck!
Another thing to consider: Look at the back of your toilet with an inspection mirror, if it's too close to the wall for you to comfortably view. My piece of garbage Dometic 300, has a deep hollow where the water supply connects. Between the top and bottom halves of the unit, there is a seam. What happened in my case was that the sewer smell in my unit was so strong that I was going crazy trying to flush the tank, and use this deodorizer, that deodorizer. Finally, I stuck my head in my toilet! No smell, whatsoever. Then, I caught another horrible whiff. It was coming from the damn hollow, in back of the toilet! The seam was allowing foul water, from flushes, to collect behind the toilet. I took the toilet outside, turned it over, watched it drain, pressure washed the hollow, dried things out, caulked that seam, no trouble after that.Sir. I am so sorry. I was thinking about something else when I typed that date. It’s actually a 2019 forest river sandpiper 370flok. I bought it brand new from the factory. I had it custom build. Took them about a month and a half and then had it shipped to me here in Texas. But last night I watched several YouTube videos about installing new units and I have a really good idea how it all works now. So I’m planning on next week pulling the unit and looking all around where it was mounted. I have a big ac vent about 3 feet alway from the ac in the ceiling. I’m betting there is something going on there in that space. But I’m going to seal it up real good and hopefully that fixes it. If not then my next course of action it to remove the vent on the roof and add another pipe about 10 feet in the air for venting. The current sewer vent is about a foot and a half from my ac unit. So after I seal the ac really well and raise the sewer vent a little higher I should definitely not have anymore sewer smell in my bedroom. Lol.