Sewage smell from the sink faucet in the bathroom

[M -N]

Sewage smell from the sink faucet in the bathroom

 

[WhittleBurner]

That's usually from the water heater, what trailer do you have? Tanked it tankless heater?

 

[Second Chance]

Thread moved to Plumbing and Water Systems. Do you have a question? What model of RV do you have? Whenever we've had smell issues with sinks, it was the air admittance valve. Cleaning or replacement of the AAV always fixed the issue.

Rob

 

[Tony_in_AZ]

Ya , check the Air admittance valve... I add a cup or so of Pine Sol to each gray tank every 3rd dump or so. Not sure the Pine Sol does anything.

 

[Knightclimber]

Do you have unused washer lines? My camper had washer lines that came off of the bathroom lines. The water in the washer lines would become stagnant and very smelly and end up leaking that into the bathroom faucet. Once I added shut off valves for the unused washer lines, the smell stopped happening.

 

[BobinICT]

We've had that happen after we have been on the road for a while. All that stuff you spit down the drain can get a little ripe. When that happens I pore some of the bio solution we use for all tanks into the drain and let it sit. Usually takes care of the problem.

 

[Summit1]

While I hesitate to diagnose a problem from afar, I always recommend checking the simple stuff first. Others here have recommended the Air Admittance Valve as being the cause of foul drain odors. The valve can be obtained from building supply and hardware stores and is not expensive. Replacement requires just a few minutes. I bought a pair from Homey Depot and replaced both (bathroom and kitchen) when one failed.

 

[tex315]

I had that same smeil, traced it to the kitchen sink, found the AAV to be very loose. Tightened down have not had that problem since.

 

[Steven@147]

There are different things that can cause a foul smell in the water supply. Yes stagnant water in lines that are not used can do this. Also if you winterize and RV antifreeze gets trapped in unused water lines like the clothes washer line, it can leach back into lines that are used. We also installed shut off valves in the hot and cold lines for the clothes washer near the nautilus panel.

Bad hot water tank anode rod, needing to be replaced can also cause a foul odor in the freshwater line.

Or odors coming from the sink/shower drains or black tank odors. Also whether sink/shower drains have traps installed. Could be a dry trap.

And yes bad AAV or Air Admittance Valves can be the source. We have found the type of AAV valve installed makes a difference to keeping the smell out of the RV.

This type of AAV has like a trap door (plunger) inside or flapper that closes to keep smells from getting out of the plumbing lines. If the trap door is stuck smells can get into the room. Its also usually the cheapest. You can use soap and water to clean them out so the flapper works again.

This type is usually way more expensive and does not have a flapper or trap door so foul smells can get out into the air. We changed our AAV to this type and had a lot of issues with foul odors coming from the kitchen and bathroom sink drains. Went back to the cheaper black ones and it solved our problem.