# septic odor when return to camper



## kellyboy

I need your help 2Coolers.... I bought my first camper about 4 years ago. Have really enjoyed it. I have kept it down on the coast for the past two years and use it at least twice a month. When I leave I dump the tanks and flush the sewer tank at least three times and close the valves. Then I drop a septic bag down the toilet and run water in the toilet for about two minutes so that the septic bag can do its thing. The instructions say it helps with odor for about 7 days. The problem is I don't return to the camper for two weeks to a month sometimes. But each time we return to the camper I immediately drop a deodorizer down the toilet but as soon as I flush the camper fills with the septic smell. By the next morning all is fine. What can I do to avoid having to deal with the smell every time we arrive at our camper. Your suggestions would be greatly appreciated.


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## djwag94

I have always used a liquid deodorizer while at the coast & have left it for a month without that problem. Never HAVE used tablets or powder packs.

Try putting 8 oz of liquid deodorizer in the toilet & completely fill the bowl with water before flushing & *then flush quickly*. Don't hold the flush handle open but a couple of seconds. Repeat as necessary. 
You might try leaving the entry door open, raise bathroom vent & turn vent fan on while you QUICKLY service the toilet.

RV toilets don't have the water barrier, like a home toilet, to prevent the fumes in the tank from escaping into the bathroom. The longer you hold the flush valve open the more fumes are allowed to enter RV. If it stunk the whole time you were there I'd say a loose or clogged vent but since you said it was gone by the next day, I wouldn't be too concerned with that.

You could have a buildup in your tank since it's been sitting for a couple of years. Get a wand/spray nozzle if you don't have one or your trailer is not equipped, or one of these.

Good Luck & tight lines.


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## kellyboy

I have both. Bought the flush king clear attachment before I realized my camper was equiped with the flushing system. I will try the liquid deodorizer and see if that lasts longer. It seems that the powder packs just lose there effectivness after several days. Maybe the liquid stuff lasts longer. Another issue I have that I have always asssumed was normal is that when I dump the tanks, before we leave, it always fills the camper with septic smell. Toilet lid is closed and sealed but when I run the flushing system I still get the smell in the trailer but we can vent the trailer and it will go away. Is this normal?


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## FLAT FISHY

You must build volume in your tank then dump it,,,do not leave the valve open all the time..then before you leave add clean water to then dump it when u return


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## djwag94

kellyboy said:


> I have both. Bought the flush king clear attachment before I realized my camper was equiped with the flushing system. I will try the liquid deodorizer and see if that lasts longer. It seems that the powder packs just lose there effectivness after several days. Maybe the liquid stuff lasts longer. Another issue I have that I have always assumed was normal is that when I dump the tanks, before we leave, it always fills the camper with septic smell. Toilet lid is closed and sealed but when I run the flushing system I still get the smell in the trailer but we can vent the trailer and it will go away. Is this normal?


^
No, that isn't normal at least not on mine. What area do you first smell the fumes coming from when flushing? bathroom, living area etc,

If you believe it's coming from the bathroom/toilet area, The base seal between the toilet & floor could be torn, worn or compressed allowing gases to escape from the tank at the toilet base. Might try snugging the toilet base hold down bolts. "Do not over tighten". Replacing the seal is not that difficult either.

Get on the roof & check the condition of the vents & vent caps. They have been known to get bent in, knocked off or obstructed which can prevent the tank from venting properly.

Good luck.


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## Don Smith

Instead of the deodorizers, try using Rid-X for RV's. Leave a few gallons of water in the tank and add a couple of ounces of Rid-X. Make sure you use the kind that is for RV's.


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## MikeS2942

clean out the holding tank when you return if possible. I installed a clean out full time and backwash my tank when I dump.


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## bigfishtx

Are you leaving your grey water valve open? You may have septic fumes backing up to the camper that way. Try keeping both closed until they are dumped, dont have the grey water open during the black water dump. You also have a breather valve in your bathroom somewhere. It could be stuck open or shut.

Google your rv model with the issue and you will probably find the answer.


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## redexpress

Might try adding some Dawn dish soap or fabric softener as well. It's supposed to help keep the tank slick so "deposits" don't stick.


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## INDIANAINTEXAS

On both of your tanks. Black and grey there is a vent pipe so there is no build up of pressure. Sounds like the black tank may have a blockage in it. On the roof there are vent caps that cover the pipes that came from the tanks make sure they are working. Close everything and hook a leaf blower to the dump valve and open the black tank valve. Air should come out the roof vent pretty easily. If not you have a blockage. Good luck


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## kellyboy

Is that the normal thing to do? Let the black tank sit without dumping when you leave and then dump it when you return two weeks to a month later? Seems like it would compound the problem. 

There are two instances when we get the septic odor in the trailer. When we arrive and drop a septic bag down the toilet. I flush it down very quickly so that the valve doesn't stay open long. But the smell enters the camper. But in a few hours the deodorizers has done its thing and it is safe to flush again. Then when we leave and I dump the tanks the camper fill with the smell again. 

I will definitely check the vent pipes. That could be the cause of the smell when i dump but I don't think it the cause when we arrive because after the deodorizer kicks in we have no issue. I will also check the seal between the toilet and the floor. But if that is where the leak was coming from then I would think the camper would smell when we arrive and it doesn't until we flush for the first time. 
I appreciate all the suggestions. They are all very helpful.


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## djwag94

In your OP, you said, you dump, flush & treat your tank before leaving. IMO, that's the best way for your situation. Use liquid deodorizer.

In your case, I'd also dump & retreat the tank upon arrival. See previous instructions & Use Liquid deodorizer.

You apparently have an accumulation of "Stuff" remaining in your black water holding tank that flushing & dumping is not cleaning & evacuating, thus the "foul Odor" when flushing. If you're not already doing so, close the dump valve while flushing your tank until the tank is 3/4 to almost full & then dump the tank. The swirling action with this amount of water may eventually loosen the "Stuff" that's stuck inside and help eliminate future "foul Odors".

I keep my trailer on the coast during the spring & summer, when I leave, I dump & flush my tank, close the valve, fill the tank about half way with water, re-treat using Liquid deodorizer & then pour 20-40 lbs of ice into it thru the toilet. The ice rattling & banging around in there during my return trip really cleans the tank & sensors. It's shocking the amount of "Stuff" that comes out when it's dumped.

Did I mention using a liquid









Have a Happy 4th, Y'all.















:texasflag


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## bigfishtx

One other thing, if you leave your grey water valve open you can get sewer fumes in from the sewer drain line. If you have a washer connection in your rig, make sure you pour water into the drain line to get the trap full of water and keep fumes from backing up.

I know we have trouble with sewer fumes coming into our RV through the sink and Washer lines from time to time.


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## smokinguntoo

I'm wondering if you got some dirt dauber nests clogging the vent line. Pop the cap on the top of the black water vent and run a closet auger gently down the vent. I'll bet it is plugged. I haven't tried it, but a water hose MIGHT work. See if it fills up the vent tube.

I like the flush line that sprays the inside of the tank from a fresh water hose. Most units have them, and if you don't cheap and easy to install.

SG2


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## kellyboy

I keep all the valves closed at all times. I only open them when I dump before we leave then I close them again. The rv park has nice facilities so we only use the toilet for number one. Been that way for the last few years. My 2005 Heartland Landmark has a water hose flush line that flushes the black tank. I use it everytime I flush the unit when we leave.


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## Tuff

Provided your vent tube for the black tank is not obstructed (not really sure how that would happen)-get a venturi vent top.

I experienced similar problems when I lived in my toyhauler during the week and left for home on weekends. I installed one of these rascals and all my problems went away.

If you regularly empty and "rinse/flush" your black tank, you won't need the chemical deodorizers (YMMV).

http://www.campingworld.com/shopping/item/cyclone-sewer-vent/31992

Somebody was ragging on Camping World the other day, you can find another source if you don't like them. Several local supply shops should have the part in stock.


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## kellyboy

Thanks Tuff

I bought some liquid deodorizer. Grey water tank deodorizer. The grey tanks have been neglected. I don't ever think about treating them. I also bought the Cyclone RV Holding tank vent. Looks similar to the one you suggested Tuff. If this doesn't get it done then I will start looking for leaks.


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## Kbrede2

Kellyboy,
Had the same problem when we got our motorhome. ALWAYS had sewer smell, especially when traveling. Installed the Cyclone Vent that Tuff mentioned and it really helped the problem. I also discovered that I had a leaking gasket under the toilet. Replaced it (just make sure your black tank is VERY clean before you remove the toilet!) and no more smell! 

For chemicals, we've tried everything on the market. Here's my recipe;
1 cup Lemon Pine Sol
1 cup Lemon Ammonia
1 cup Baking soda (Arm & Hammer stuff) buy it at Sam's in BIG bag.
1 cup liquid Laundry softener (cheaper the better)

Dissolve the baking soda in a large mixing bowl, add the Pine Sol & Ammonia and the Laundry softener last, fill rest of bowl with hot water so everything is mixed up. Pour it into your black or grey tanks. Having a couple of gallons of water in there helps it. Don't dump your Black tank until it's 3/4+ full. Traveling with your tank 1/2 full and with this mix will also help dislodge the "stuff" and also coat the walls of the tank with the mixture so other "stuff" doesn't stick to it. 

Another trick to do on occasion is to fill your tanks 1/4 full of water and dump a few bags of ice in there, then go for a drive (or tow). Rough roads and fast lane changes help. The ice will help to breakup "stuff" as it sloshes around. 

4 years full time rving using this method, and now been a part timer for 2 years, we have no issues with our tanks. Good luck.


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## kellyboy

Thanks kbrede2

And thanks to all of you for your suggestions. I don't believe I have a leak in the toilet because once the septic deodorizer kicks in there is no smell until we flush for the first time once we return after a couple of weeks. If there was a leak then I think the trailer would smell upon return but it doesn't start to smell until we flush the new deodorizer down when we get there. 

Then it starts to smell the trailer up again when I flush the black tank at the end of our trip. I am taking yalls advice and I have bought the cyclone vent and intend to install this weekend. I will also check for good air flow in the vent.


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## sea hunt 202

Good info


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## wisslbritches

Do you turn on the fan before you smell the sewer gas? Most of the exhaust fans on the newer units are very high powered and believe it or not they can create a vacuum to where it's pulling fresh air from the vent then thru the black tank and up the toilet...especially when you run the fan when flushing.

I've found best way to clean a black tank is to not only use the on board tank rinse but to ALSO backflush using the previously mentioned Flush King or something similar. When doing the Flush King use the 8 second rule: close the valve and fill for 8 seconds. Good idea to have someone inside watching the toilet just in case 8 seconds is too much


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## kellyboy

I can dump the tank without having any odor. What I discovered last week was the smell occurs when I use the onboard flush system to clean it out after dumping . As soon as I start that flushing process the trailer fills up with sewer odor.


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## kellyboy

And no I do not run the fan when using or pumping the toulet


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## Tuff

Are you still having the problem after installing the venturi top? 
Did the "smells like sewer when returning" issue stop?

The "smells like sewer during dumping/cleaning" is a different issue. The smell is sewer gas entering your camper from your sewer connection. It is not an issue with your camper, but with the sewer receptacle you are dumping into. The solution is to close your black dump valve while you are "flushing" the tank. Open to drain the flush water and if your sewer hose is filled with water, the sewer odor from the receiving sewer won't back up into your trailer. With that said, do not activate your tank flush and walk off and do something else - obviously inattention can result in a huge mess. Since there is not a "P" trap in the system design of emptying your black tank, you have to either close the pipe or fill it with water. Depending on how bad this bothers you and where you are dumping, you can install a trap down stream from the port you dump into.

Unless you have a gas engine powered fan, running the exhaust fan will not draw odor when you have the venturi top installed.


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## kellyboy

Thanks for the input tuff. When I flush the black tank with the onboard flush system the black valve is always closed so the sewer smell can't be coming from the RV park. I suppose it is the flush system hitting the walls of the black tank and stirring up the odor. 

On my last visit I had intended on installing the cyclone vent but when I arrived and took a look, the previous owner had already done that. 

When I arrived I dropped a deodorizer down the toilet before I even turned the water on. I didn't use the facility's for about an hour and when we did there was no odor.


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