smell in kitchen and front of coach

[lyonstom]

2019 Phaeton 40IH. Returned from trip and parked coach in our garage. After 20 days there's a nasty smell in the front of the coach. Before leaving last RV Resort, I flushed the black tank for almost an hour and drained the gray tank, so am thinking this could be the gray tank causing the smell.
We always treat gray tanks with chemical just like black tank while traveling or camped.
I poured a gallon of chlorox down the gray water drains a couple of days ago, but still really stinks in front of coach.
Thoughts?

[dizcom]

Start with the obvious, check your traps to see if they have water in them and check to see that your vents are working properly. Any seals around the toilets, etc. After that look for the not so obvious, dripping drain lines somewhere, or dishwasher holding some water. Rats building a nest leave a smell also. Or something that crawled up somewhere and expired. Good luck.

[Hpozzuoli]

After you flushed the tanks did you add a copious amount of toilet Chem? I have found simply draining and flushing the tanks doesn’t negate the bacteria in the tanks. You need toilet chem. I do 2 bottles in the crapper and split the other bottle between sinks for the gray tank. I even hit the shower drain making sure all traps get some chem as well.

If you are using the toilet chem in your tanks and still getting the smell I would add more. It will evaporate a small amount and dry up and turn to goo. At that point it looses its effectiveness.

If you are well covered with toilet chem my next step would be to look at the garage. Enough ventilation in the garage? Could be the fumes from the tanks dropping down from the roof vents and settling back into the coach. The front has more opennings than the rear so it makes sense that’s the path the stink takes.

Is there still water on board? Have you verified nothing is leaking on the fresh water side?

[garykk]

You sure it’s not a dead critter somewhere in the genset compartment , bay or underbelly? Could also be in a cabinet drawer.

[Warhorse6]

Check your air admittance valve under the bathroom sink. Should look like a cap screwed on a vertical pipe. Sometimes they stick open and you get that smell. You can get a replacement for under $10 at lowes or Home Depot. I always carry a spare.

[wolfe10]

Originally Posted by Warhorse6

Check your air admittance valve under the bathroom sink. Should look like a cap screwed on a vertical pipe. Sometimes they stick open and you get that smell. You can get a replacement for under $10 at lowes or Home Depot. I always carry a spare.

That is where I would start. Do the "sniff test" under the sinks.

[DRM901]

Originally Posted by wolfe10

That is where I would start. Do the "sniff test" under the sinks.

Agreed. A quick check on them is to put a plastic bag over them, sealed with a rubber band or tape.

[LMHS]

A lost potato that is rotting away smells ghastly.

[lyonstom]

Thanks everyone for your replies. Found the culprit for the smell under kitchen sink. The air admittance valve counterweight was sticking open due to gunk on the pin that the counterweight rotates on....
Cleaned with WD40 with silicone lube and got the counterweight rotating freely. Since this seemed to work, I thought I would test out the cleaning fix before replacing the valve.
I found all 4 of the aav valves in the coach and cleaned them too..
I found the valves at Lowes, so picked up one to carry as a spare in case the cleaning fix didn't cure the issue.

[LETMGROW]

Originally Posted by lyonstom

Thanks everyone for your replies. Found the culprit for the smell under kitchen sink. The air admittance valve counterweight was sticking open due to gunk on the pin that the counterweight rotates on....
Cleaned with WD40 with silicone lube and got the counterweight rotating freely. Since this seemed to work, I thought I would test out the cleaning fix before replacing the valve.
I found all 4 of the aav valves in the coach and cleaned them too..
I found the valves at Lowes, so picked up one to carry as a spare in case the cleaning fix didn't cure the issue.

Nice work. I guess it wasn't an errant piece of fish which missed the frying pan after all.