Tech Tip- How To Stop RV Holding Tank OdorsPosted on February 18, 2014
I am sure we all remember the disastrous experience that Bob Munro, played by Robin Williams, had in the movie RV when he was dumping his holding tank. He pretty much covered the topic thoroughly of what not to do when you are dealing with RV waste tanks.
One of the most common complaints we hear in reference to the black tank is that it emits an odor. The black tank is connected directly to your toilet. There are a several possible reasons for tank odor to get into the living compartment. First, if your toilet is not holding water then you have lost the water barrier that keeps the waste gases from getting into the living area. There are a couple of things you can do to solve this problem. First, debris will often accumulate on the blade seal which does not allow the blade to proper seal and hold the water in the toilet bowl. Take a coat hanger and clean any debris off the lip of the seal. It is also a good idea to apply a little Vaseline to the seal this will help the blade close more easily.
Second, if cleaning and lubricating the seal did not solve the problem then the seal needs to be replaced. In some toilets you don’t have to remove the toilet the old seal will pop out and the new one pops in. But in some toilets they have to be removed or split in two to replace the seal.
However, if you toilet holds water then there are a couple of other things that cause odors. First, the cause maybe from not using a quality chemical. In most cases you want to use an enzyme based chemical or a probiotic based chemical. In addition to using a good chemical it is vital that when you dump your black tank that you flush it out thoroughly. This mean filling it up with fresh water and dumping it a couple of times.
There are times that you think you are smelling a black tank odor when in reality the odor is coming from the grey tank. The residue from soap and food remnants can grow bacteria which causes odors. There are various chemicals that are made to treat the grey tank. This tank needs to flushed as well.
If you are doing all of the things listed above faithfully. There is a possibility that you have a venting issue. It could be a vent that has become clogged or maybe the vent valve is not working. In addition, to increase venting there are several devices that go on your roof, replacing your plumbing vent, increasing venting airflow to help in the expelling of waste gases.
Finally, when dumping your tanks, don’t dump your black tank unless it is 2/3 full. If it is less than 2/3 you run the risk of leaving solids in the tank. So, if you need to dump, but are not full enough just add some fresh water until you reach the 2/3 mark before you dump. Also, always dump the black tank before you dump the grey tank. The reason is that the grey tank has more water than solids and it will help flush the plumbing. However, you still need to run additional fresh water through both tanks.