That Toilet Smell

GoGood

Member
RV LIFE Pro
Joined
Aug 4, 2024
Messages
27
Location
Loveland, CO
I used the trailer once, drained the black and grey tanks. Ran water thru the black tank...but the trailer stinks like an open sewer line.

All tanks are dry right now, so I put a bucket of water down the toilet, like filling the J-Trap on an unused shower or sink and it stopped the smell.

Should I keep a gallon or two of clean water in the Balck tank? What happens during the winter?

I was thinking about blowing the system dry and draining it for Winter...maybe I shouldn't?
 
Nothing about that sounds right. If it is venting properly, which isn't always the case (see my long post on that subject if you can find it), it should not smell inside. Even if you had the same problem with your black tank as I did on mine, it shouldn't smell until you have it partially filled (25% in my case). Adding a bucket of water shouldn't make a difference. Does your toilet burp when you flush?
 
I had that problem. The tank vent pipe was not inserted into the tank. It's at the dealer right know getting fixed under warranty, I hope.
 
If I empty my black tank and just leave it (in my temperature controlled garage) the toilet will start to smell after a week. But you don't get that smell until you flush the toilet (or otherwise open the flush valve with or without water). So I put in about 3 gallons of water and an odor control tablet (or the Pinesol/Calgon/Water mixture).
 
Be sure to leave some water in the bottom of the toilet. It helps seal the flapper and prevent sewer smells from making their way back into the coach.
 
Be sure to leave some water in the bottom of the toilet. It helps seal the flapper and prevent sewer smells from making their way back into the coach.

Yup.... a dry or leaking seal on the flush flapper will alow a stinky poo tank smell to enter the coach. Had a Jayco TT once and it would slowly leak out the water of thw bowl and would stink up the RV.
 
If your vent pipe on the roof is producing bad odor and you have a roof top fresh air vent open, the smell will very likely come into the interior through that. Happy Camping!
 
I used the trailer once, drained the black and grey tanks. Ran water thru the black tank...but the trailer stinks like an open sewer line.

All tanks are dry right now, so I put a bucket of water down the toilet, like filling the J-Trap on an unused shower or sink and it stopped the smell.

Should I keep a gallon or two of clean water in the Balck tank? What happens during the winter?

I was thinking about blowing the system dry and draining it for Winter...maybe I shouldn't?

Everything mentioned helps to alleviate the bad smells inside the RV. Sometimes running the exhaust fan in the bathroom can suck bad smells up through the drain plumbing lines.

Here is typical layout of the sewer plumbing lines, that we have in our Solitude, not the same as all RVs though. The black dots in the diagram are the AAV (Air Admittance Valves) valves or the one-way valve for the clothes washer drain line..
Grey tanks can stink as bad or worse as the black tank. In our bathroom we have dual sinks and Notice that the sink drains, even though they have traps, are tied into the roof vent lines. If you let the tanks get too full it can plug up the vents going up to the roof. Also notice the black tank vent and bathroom grey tank vent are tied together.

Bad or stuck AAV (Air Admittance Valves) can also allow bad smells to backup into the RV. We had replaced our AAV valves with what we thought were better valves but they didn't have a trap door in them to close them off after letting air in. We went back to the cheaper AAVs with trap doors in them from Home Depot and that resolved our bad smells.
 

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After investigating with a flashlight and my camera snake (normally used for running wires in walls) I found the new RV had the discharge pipe from the toilet to the black tank coated in dried poop. The one night we used it, neither of used did that in the toilet.

It had to happen at the dealership, Blue Compass in Cheyenne. I power washed the pipe thru the toilet flush hole then flushed the black tank 5 times, using a water meter to be sure I filled it. I put 30 gallons in each times, it is a 37 gallon tank. The first time I added a bit of Dawn and drove it around the block, 5 miles.

Smells fine now. I will purchase one of those metal wands with side holes for flushing it before putting it away for the winter
 
After investigating with a flashlight and my camera snake (normally used for running wires in walls) I found the new RV had the discharge pipe from the toilet to the black tank coated in dried poop. The one night we used it, neither of used did that in the toilet.

It had to happen at the dealership, Blue Compass in Cheyenne. I power washed the pipe thru the toilet flush hole then flushed the black tank 5 times, using a water meter to be sure I filled it. I put 30 gallons in each times, it is a 37 gallon tank. The first time I added a bit of Dawn and drove it around the block, 5 miles.

Smells fine now. I will purchase one of those metal wands with side holes for flushing it before putting it away for the winter
Or, more likely, the person driving it from factory to dealer.
 

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