Understanding the Holding Tanks on an RV Rental

Dumping the holding tanks on an RV rental or camper rental is sometimes a mystery to newbies. Think of an RV being like a house with its various systems such as electric, plumbing, HVAC, sewer, etc. Yes, there’s a sewer system — the stuff has to go somewhere!  Sure, this is not the fun part of RVing, but it’s essential. And it’s really not difficult and does not take very long if you follow these techniques.

Your RV rental has two sewer tanks. One tank is named Gray and the second tank is called Black. The Gray tank holds liquid waste from the kitchen sink, bathroom sink and shower/bath. The Black tank holds solid and liquid waste from the toilet. Get it now? Black is the dirtiest stuff and gray is not quite so foul. At the end of these tanks which are located under the RV, there is an outlet where you will connect the sewer hose in order to empty these tanks. Like we stated before — the stuff has to go somewhere!

When Should You Dump the Sewer Tanks on a Camper Rental?

You should empty the sewer holding tanks on a camper rental when they are full or near full. There is a gauge on the RV that shows the status of each holding tank. Usually it’s stated, Empty, 1/3 Full, 2/3 Full and Full. On a side note, in addition to the Gray and Black tanks there is a Fresh Water tank for usage when not connected by hose to “city” water. One reason to empty the Black tank when it is at least 2/3 full is because the weight of the waste effectively creates the gravitational force that pushes the matter out of the tank and down the hose to the sewer when the valve is opened. This concept is why you do not simply leave the Black tank valve open all the time and the hose connected to the outside dump hole and expect the tank to fully empty. FYI-If you rent a camper for just a few days, then the Black tank may not fill up which is what you want before dumping. If so you can fill it by flushing the toilet until the gauge shows full and then dump it. Generally, if you return an RV rental to the dealer with the sewer tanks not empty you will be charged an extra fee. However, a few dealers offer tank dumping within an all-inclusive price. Inquire to find out the policy with your camper rental.

Equipment / Supplies Required for Dumping the Tanks on an RV Rental

Dumping holding tanks on an RV rental is not difficult but you need to follow a procedure to ensure it is done properly. Furthermore, you need to bring several items with you in the RV storage bay(s). These items may or may not be provided by the RV rental dealer. Ask and verify. Here is the list of essential items:

  • RV Sewer Hose and connectors; if you think your sewer hose is too short then carry two hose and their connectors
  • Disposable Gloves
  • Holding Tank Deodorant •A Garden Hose (i.e., used just for holding tank maintenance and not drinking water)