Sewage Odor Comes and goes

[yingpin]

Hello Everyone,

I tried to search for a similar issue or solution but could not find anything. If there is a thread for this please don't hesitate to post the link in a response.

I took the family camping in our 2005 Jayco Featherlite Exp 25E. We purchased this Hybrid used two years ago and absolutely love it. A few weeks ago I caught an intermittent odor of sewage. This weekend I noticed it more regularly. I made sure that we added blue solution to the toilet and added about two gallons of fresh water. I don't think this is something that my dad has done after every visit and I wonder if this is what is causing the issue. It would come and go and surprisingly (to me) it was not coming from our bathroom. We only pee in the toilet and the smell seems to be coming under the sink on occasion and would also seem to come from the storage where the water heater is.

At the end of the trip the tanks were both nearing full and my wife put about a gallon of stove hot water down the kitchen drain. WOW, we had to evacuate. Since I did the set up and break down this time (my dad normally does this since he has more time). I drained the black water, drained the grey water, and rinsed the hose. I checked the gauge and the grey water read empty however the black water read 1/3 full or the lowest setting. I still decided to add a double dose of blue solution and added 2-3 gallons of fresh water through the toilet hoping that the drive back would break up any residue.

I understand that there are vents for the plumbing, what should I look for and do you have any recommendations on what I can do to further eliminate this issue?

[msturtz]

Ok, a few things to consider. If you don't regularly clean the tanks and plumbing you can get very foul odors. I regularly put a bio-degradable solution into the greywater tank to keep the smell down.
If this was not done you should clean it out by doing the following:

1. Put about a cup of Kirkland signature automatic dishwasher detergent down all of the drains
2. Add several gallons of boiling hot water
3. Drive around for about 30 minutes or so
4. Completely fill the grey tank with as hot a water as you can get
5. Dump the grey tank.

You may have an issue with your vent pipes. If they are plugged it will cause no end of problems such as slow drains and odors. You may find a one way "burp" valve under the sink or other location that connects to the plumbing. The idea of this to allow one way into the tank not out. Ensure that this valve is in good condition and not leaking. Also look on the roof and ensure that the vent stack isn't plugged.

To clean the black tank:

1. Purchase 2 extremely large bags of ice or 4 smaller bags of ice and flush them down the toilet
2. Flush a gallon of household bleach into the black tank
3. Drive around for about 30 minutes
4. Completely fill the black tank with as hot a water as you can get
5. Empty the black tank carefully monitoring the debris exiting the tank (I use a Valterra clear elbow to verify the contents exiting the tank.)
6. If you see the debris exiting the tank (you probably will) keep refilling the tank with hot water until you see nothing but clear water exiting

To keep the tanks from becoming gunked up always add 2 Oz of blue toilet chemical and at least a gallon of water (fill the toilet bowl up two or three times) and leave it that way before use. Adding chemicals after the toilet is being used is of limited benefit. If you will be using the toilet a lot during a longer stay add more chemical. When it is time to dump your tank fill it completely and dump and repeat until nothing but clear water is exiting. Regularly (once a season) add some bleach to all grey water drains to keep the drains clean. Every other trip or so add biodegradable chemicals to the grey tank to keep the gunk and odor down.
Good luck!

[Mustang65]

If your odor is like the one I had it is more than likely coming from the pee-trap vent under the sink in the bathroom. It is designed to be a one way valve (rubber diaphragm), but i noticed that ours was letting the odor pass into the TT. I also noticed that the odor increased as the exhaust fan in the bathroom was on the fastest speed and the bathroom door was closed (only a one inch opening between bottom of the door and the floor). This causes a vacuum since the bottom of the bathroom door does not allow enough air to enter, and the valve under the sink somehow allows the odor to enter.
A couple things you can try..
- Always make sure you have a window open when the exhaust fan is running.
- Keep the fan at a lower speed.
- Turn the fan off anytime you flush the toilet
Not recommended by a lot of people, but the only way I was able to totally eliminate the odor was to tape closed the pee-trap vent under the bathroom sink. It has been over 6 months now and I have not had an odor, or any related issues. I initially watched the sink to see if it had an effect on the speed of the water draining, but there was none. Oh, and shut the fan off when flushing.
They need to redesign the air valve on the pee-trap.
Don

[msturtz]

Originally Posted by Mustang65

If your odor is like the one I had it is more than likely coming from the pee-trap vent under the sink in the bathroom. It is designed to be a one way valve (rubber diaphragm), but i noticed that ours was letting the odor pass into the TT. I also noticed that the odor increased as the exhaust fan in the bathroom was on the fastest speed and the bathroom door was closed (only a one inch opening between bottom of the door and the floor). This causes a vacuum since the bottom of the bathroom door does not allow enough air to enter, and the valve under the sink somehow allows the odor to enter.
A couple things you can try..
- Always make sure you have a window open when the exhaust fan is running.
- Keep the fan at a lower speed.
- Turn the fan off anytime you flush the toilet
Not recommended by a lot of people, but the only way I was able to totally eliminate the odor was to tape closed the pee-trap vent under the bathroom sink. It has been over 6 months now and I have not had an odor, or any related issues. I initially watched the sink to see if it had an effect on the speed of the water draining, but there was none. Oh, and shut the fan off when flushing.
They need to redesign the air valve on the pee-trap.
Don

You should be able to replace the vent to allow proper ventilation of the plumbing system and not allow gas to enter the coach. In RVs rather than homes the "Air behind water" rule isn't as bad because of the tanks and the typically lower water volumes going down the drain. That said, I would replace the valve if it is defective.

[Mustang65]

Sorry,
One item that I forgot to mention in my last post (an important one) was that I switched out the pipe vent valve from under the kitchen sink with the one in the bathroom sink. The result was the same. The odor was still present, from under the bathroom sink. I then decided to tape it as a last resort, and as I mentioned there are no issues since then. The reason that the odor is not emitted from the kitchen sink vent, is that there is always fresh air coming in through the open windows (outside the bath area) or 2nd roof vent, as it takes the path of least resistance. I always have a window cracked.

This is why I believe they need to redesign the valve.
Don

[RoyBraddy]

I had similar occasional bad smell coming from the bathroom and finally tracked it down when the exhaust fan was being turned on in the bed room.

I guess the fantastic fan was sucking the smell up thru the POT...

Roy Ken

[yingpin]

Thanks for the replies. My scenario is a little different because the odor is not present in the bathroom....ever! The only source of the smell that I can track down is on the other side of the trailer and it varies from either under the kitchen sing, or in the storage compartment to the right where the water heater is. When the wife poured hot water down the kitchen sink the smell was over whelming so I am thinking it may be the gray water tank but it smells like raw sewage.

I did see a video yesterday that states we are supposed to shut the black water release valve when dumping before we open the gray water dump valve to avoid contamination. We have left both open in the past. If you drain the black water first then the gray water, even if both valves are open, I don't know how the gray would be contaminated since it is flushed last???

[lx22f/c]

I had the same problem with smells. I would only smell them once in a while and like you would try and mask them. Finally figured out that the smell was more so on windy days or after opening camper after traveling. I installed the siphon 360 on both tanks and just like that no more smells. Good luck

[Jagiven]

Where are your tanks in relationship to the odor and the sinks (both bathroom and kitchen)? Could you have a broken pipe somewhere?

We get odors once in a while. Every spring couple of weeks after our first use of the year. That is from a bacteria bloom once we add fluids. We also get it in our bathroom from not using the shower. The shower trap either dries up or the water is sloshed out and down to the tank. So I now pour a little water down the drain periodically and have a drain stop.

Pouring boiling hot water down the drain could kill the good bacteria, so will pouring bleach down the drains. Having good bacterial health is very important.

[mcfarmall]

Check the air admittance vent valve under the sink. It should be screwed into the plumbing near the trap. Sounds like it's sticking and not closing off the sewer gasses.