Smelly kitchen sink

[richard1]

We have a double sink in the kitchen that emits an awful odor, especially when using hot water to do dishes. The hot water tank is under this cabinet. I have checked for leaks around the water tank, drain pipes, and vent pipes. All show no leaks or loose fittings. The hot water tank was drained and flushed about 5 months ago. There doesn't seem to be any bad smell or odor to the water itself. This condition seems to be worse when the sink hasn't been used for a couple of days. Any suggestions to remedy this problem would be greatly appreciated!

[ArmyEOD]

Maybe you have some rotting product stuck in the trap. Maybe try a flexible plastic drain cleaner ($2.00 at Lowes) it has plastic teeth that will grab and lossen most anything in a drain line. Hope this will help you out.

[RJay]

I have a similar problem at times on the bathroom sink. I think what happens is the wind over the roof vent creates a low pressure in the tank which sucks some of the water out of the P trap allowing odors to come up from the tank. If that's the case just run the water to refill the P trap and see if it has an effect on the odor.

[Batman_777]

There is a vent valve under the sink. There will be a plumbing vent valve for each sink, shower and washer. Very inexpensive, easy to replace and the most common cause of odor around the sink area.

[RJay]

Batman, good point. It's something the OP should check. I have one in the bathroom and still sometimes get the odor. I guess it could be defective.

[Paul R. Haller]

I'm guessing that under the sink you may have a one way valve on the vent line. They screw into the ABS sink at the top of the vent line. They can fail or get gunked up not allowing air in to vent the sink. If this occurs the trap will empty and gasses and odors from the holding tank come up through the sink trap into the living space.
Two things can help.... Clean out your sink holding tank using the geo method or buy some bacteria enzyme to chew away at the organic stuff in the tank that cause the odor The enzyme is available almose anywhere but have seen it at camping world. The second is check to see if you have a valve on thre top of the vent. If yes pull it off and inspect it. They are supposed to work by letting air into the pipe but not out of the pipe. If you do not have a valve and the pipe extends through to the roof, it may be clogged or an insect like mud dabbers have built a nest in it. I have also heard that sometimes during construction the vent line gets pushed down too far into the holding tank. If this occurs, the pipe will vent only until it's entrance in the tank gets covered with water. Good luck and keep us posted as to what you find.
-Paul R. Haller-

[Batman_777]

Yep... I purchased a vent, replaced it and still the same... The replacement was faulty.. Purchased another... No more problems.

[RJay]

I just took mine out and it "looked" ok. I think I'll buy another one to be sure.

[richard1]

Thanks for the helpful ideas! One issue can be eliminated. That is, I have a direct vent to the outside wall. I will check out these solutions and post the results later. Thanks again for helping out a Jr.Member... this is a great site!

[Ray,IN]

That reminds me of what happens when you have a garbage disposal and don't use enough flushing water. Not your problem though. I would try using that foaming drain cleaner to clean the "P" trap and pipe walls of grease and food particles it holds. It will not harm your plumbing,. I've used it a few times with positive results.

[MikenAmber]

We had a similiar problem in our unit and purchased some drop in tablets for the grey tank cleaning. We purchased them at Camping World, they are next to the black tank cleaners, orange package. Sorry but I can't remember the name. Solved the problem.

[01zeosix]

I ~think~ your talking about Elemonate Grey Water Tabs.

I use them whenever I am "holding" my grey water. Work great. Solved my problem, too.

[Ray,IN]

Copied from the Walex website: "Elemonate™! Elemonate is a Grey Water Deodorizer Rapid Dissolve Tablet with a unique compound of enzymes, odor control agents and biodegradable surfactants."
That seems expensive for what is basically an enzyme product, and odor masking agent.