Sewer odor in my 03 Classic

[Getahobby]

I have a sewer smell in the compartment where the water pump is. The vent pipe goes up through there also. I can feel the pipe but can't see it. Any ideas how I can figure out the problem and fix it?
thanks,
Dave

[Phoenix]

There is a possibility that there is no problem. What kind of toilet deodorant chemicals are you using? Out-gassing and odors are more prominent in warm/hot weather. You may just need to add another dose or two of chemicals to the black and/or gray water tank(s).

[Getahobby]

Yes, It was a hot humid day yesterday. No chemicals in the tank. The trailers been sitting as I've been fixing/cleaning things up before our first trip in it. I've run clean water in the tank to make sure it does not leak. It's about 1/2 full.
thanks,
Dave

[Ridgerunner3]

In the hot weather we minimize odor by dumping the black tank each week. We use the Geo Method for chemical treatment of our black tank. The Geo Method just uses ordinary home laundry products for odor control. If interested do a search on the internet for the Geo Method. We are setup to dump our tanks at home into our septic system, so I do not want to use chemicals that will harm my septic system.

Also be sure you keep water in your sink drain traps and shower drain trap. The gray water tank fumes will back up into the trailer if the traps dry out. The traps will dry out pretty quickly in the summer heat.

I typically start up a freshly dumped black tank with about 7 gallons of fresh water about 6-8 ozs of liquid laundry soap and about 4-6ozs of Calgon water softener (Geo Method). We have been using the Geo Method four 4 years and have been very happy with the results.

[SteveH]

You may also want to check the toilet itself. If it won't hold water after a flush, it won't prevent gasses from returning into the bathroom.

[Phoenix]

If this is your first trip, and you are new to RVing; suggest you drain black and gray water tanks, if possible. Then, purchase and add Thetford "Campa-Chem Holding Tank Deodorant", following the instructions. This product is frequently provided with new RVs and porta-potties, and it is very likely the "blue water" you see in airline-type recirculating toilets. (Make sure the bottle contains formaldehyde; as there is a "green" version that does not, which doesn't work as well.)

You can experiment with other products later, including the Geo Method, to see what works for you; but this is a good place to start on odor control. It is probably the most effective product/method, especially in the summer heat. Thetford and other brands of toilet chemicals are widely available, including WalMart and RV/Marine parts stores. I think WalMart has the 32 ounce bottle priced below $5.

Note: This product contains formaldehyde and can permanently stain blue whatever it touches, including your hands, clothing and trailer surfaces (flooring, walls, etc.). So, be careful where it splashes; and keep the lid to avoid spilling, in case you knock it over.

[HowieE]

There is no reason to use deodorant in the system unless you just want to improve the profit margin at Wal Mart. The only time you should smell odors inside the trailer is if the right wind conditions are present to cause the sewer vent to blow back into an open trailer roof vent.

If you smell order in that compartment the first thing I would check is the seal between the tank and the vent stack. If the stack seal has broken you will get an odor. A way to test this would be to have water in the toilet, close the black water gate valve and connect a SMALL vacuum cleaner to the roof vent. If the system is tight the vacuum should Stall as soon as you turn it on. If the vacuum pulls normally there is a leak some place. Don't let the vacuum pull for any length of time if it pulling hard as it can implode the tank altogether.

Depending on how close the toilet is to that cabinet you may have to check the closet seal under the toilet.

If it were the toilet itself not holding water you would smell the odor in the bathroom.

Another possibility is a crack in the top of the Black tank itself. Tanks have cracked during hard freezes if they were mounted without slack in the mounting screws. This would require dropping the tank and sealing the crack with a fiberglass patch.