I'm a professional motorcoach driver. (Tour bus) We do use the blue enzyme packets. Although these do have deodorizers in them, their primary function is to break down the solid waste, so it doesn't clog the drain. It is especially important to remember to tear the enzyme packets open so the blue powder can release...otherwise, they don't work at all. I use a Rubber Gloves to do this because the blue dye will stain your hands. These are useful, but the included deodorizer is really no match for the smell after a short while.
Before diving into this article, you may want to watch our short video below on Eliminating Sewage Smell in an RV
The remedy is very simple: add a couple of cups of DOWNY! No kidding...on a commercial bus trip with 56 people on board, this takes care of the offensive smell for up to 3 days, or when the tank is full and has to be dropped! And who doesn't like the smell of Downey?
The cherry on top of the sundae is this: Downy is biodegradable and will not harm any seals (no, not the animals, the ones in the drainpipes).
Note from the Editor: If you still have bad smells coming from your RV's holding tank even after using Downy, you may need to deep clean your holding tanks. We have personally had great success using Thetford Blaster Holding Tank Cleaner (Pictured Above) in our RV holding tanks.
If you have taken all the steps above and you still have a "sewer-like" smell in your RV, there is one more area that you should check. You should look at your RV's House Batteries. The House Batteries are always being charged when your RV is plugged in.
Depending on the type of Converter/Charger your RV is equipped with, there is a good chance that the batteries are being overcharged and the electrolytes are being boiled. The boiling electrolytes create a smell like a sewer smell. That's why you need to check your RV's House Batteries at least once a month and top them off with Distilled Water.
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