Foul smell in laundry closet

[rynosback]

We had a foul smell coming from our laundry closet. I traced it to the one way vent. It was allowing sewer gas to enter the house. I filled the trap with water and took a freezer ziplock bag to cover the leaking vent. I secured it with several rubberbands keeping the seal tight.

[Cummins12V98]

No liquid in "P" trap allowed the lovely aroma to come up from below.

[rynosback]

Originally Posted by Cummins12V98

No liquid in "P" trap allowed the lovely aroma to come up from below.

There was water in it, but I added more. Plus that washer drain had a cap on it. It definitely was coming from that one way vent diagram. As I put my nose up to it and that was the source. I am trying to resize a picture of it on my IPad so everyone knows what I'm talking about.

[Cummins12V98]

If it had water in the "P"trap and a cap on the pipe it sounds like the Studor vent may be bad. It is supposed to allow air to draw down into the pipe but not let air up and out.

Sounds like a punch list item.

[davydee]

We, too, get that smell from time-to-time, especially if we haven't used the washer in awhile. As was suggested above, when we don't use the washer a lot, we add some water to the P-trap once or twice a week to prevent the smell. David

[GeorgiaHybrid]

The check vent valve might also be stuck open. It happens ever now and then and most have a spare in their "fixit kit". If adding water in the P trap doesn't work, start looking at the vent. You will have one everywhere you have a drain.

They can be bought VERY cheaply at Lowes, Home Depot or plumbing supply stores.

An example of one is here: Check vent valve

[Camr]

We had exactly the same experience. It was the vent check valve. The one that is installed in our 38RBS3 has a rubber diaphragm in it. When I detached the valve, I could see no trace of a defect. I applied a thin coating of silicone grease to the sealing side of the diaphragm to allow a tighter seal and have had no further issues. If you try this "fix" make sure to use silicone rather than a petroleum based grease.
I checked our local Rona hardware store and found a huge difference in the cost of vent check valves. One was $10 and the other one was $49. Nothing in between. If the silicone grease fix ever fails, I guess I'll spring for the Cadilac valve.

[GeorgiaHybrid]

Silicone grease can be bought at auto parts stores where it is sold as dielectric grease...

[blw2]

I'm finding that the air admittance valves and some other drain fittings are less than hand tight in my coach, and I'm thinking that this may be the cause of some of these leaks....

[FW28z]

Originally Posted by blw2

I'm finding that the air admittance valves and some other drain fittings are less than hand tight in my coach, and I'm thinking that this may be the cause of some of these leaks....

Same here... both of my vents were loose. It's a wonder I didn't have any stink issues.

I have since put an "Oatey In-Line Vent" into my spare parts box. Less than $6 from Amazon.

In the Oatey instruction sheet, it says you can optionally use either Teflon Tape or Petroleum Jelly to seal the vent to the pipe. It does not recommend Plumbers Putty as it will damage the vent.

However, I don't know if I would use anything but Teflon Plumber's Tape.

[rynosback]

Originally Posted by Cummins12V98

If it had water in the "P"trap and a cap on the pipe it sounds like the Studor vent may be bad. It is supposed to allow air to draw down into the pipe but not let air up and out.

Sounds like a punch list item.

Yup, added to the punch list. We have an appointment already set up with DRV.

[rynosback]

Originally Posted by davydee

We, too, get that smell from time-to-time, especially if we haven't used the washer in awhile. As was suggested above, when we don't use the washer a lot, we add some water to the P-trap once or twice a week to prevent the smell. David

Try adding I think mineral oil to your trap if you do not use it that often. As it does not evaporate like water. I'm 90% sure it is mineral oil. I would Google it to make sure that it is safe for the pipes and county drains.

[rynosback]

Originally Posted by GeorgiaHybrid

The check vent valve might also be stuck open. It happens ever now and then and most have a spare in their "fixit kit". If adding water in the P trap doesn't work, start looking at the vent. You will have one everywhere you have a drain.

They can be bought VERY cheaply at Lowes, Home Depot or plumbing supply stores.

An example of one is here: Check vent valve

Thanks. Right now I have a ziplock bag over it rubberbanded about 6 times and several wraps of duck tape. Seems to have sealed it up.

[Kerrywv]

You can get a small container of silicon at Lowes or Home Depot in the pluming section in faucet repair section.

[FW28z]

Originally Posted by rynosback

Try adding I think mineral oil to your trap if you do not use it that often. As it does not evaporate like water. I'm 90% sure it is mineral oil. I would Google it to make sure that it is safe for the pipes and county drains.

I would recommend not adding mineral oil.

Here is the problem... mineral oil floats on water.

There are two types of bacteria that can form in your holding tank, Aerobic and Anaerobic. Aerobic bacteria forms in the presence of oxygen, and Anaerobic bacteria forms when oxygen is not present.

If sufficient oxygen is present in the holding tank, Anaerobic bacteria will not normally form, or at least it will be minimal. That is one of the primary reasons for the stack vent in the holding tank that goes through the roof - to keep oxygen circulating in the tank.

Aerobic bacteria does not stink (at least as bad), while Anaerobic bacteria is the terrible stinky stuff. Therefore, it is to your advantage to promote the production of Aerobic bacteria.

If you put mineral oil or any oil less dense than water into the holding tank, being less dense than water, it can form an "oil slick" at the water line thereby cutting off oxygen to the contents - which means Aerobic bacteria cannot form... which also means, your holding tanks will form the stinky Anaerobic bacteria.

While this is not as much of a problem for the grey tank I suppose, especially if left open and hooked up to a sewer. But as a rule-of-thumb, I would not want to add any more floatsom than already gets in there from normal use.

I suppose though, this is a good reason to close the grey tank (assuming your washer is hooked to it), and adopting a "dump-when-full" approach similar to the black tank.