RV Holding Tank Installation

RV Holding Tank Installation
A black water holding tank holds the liquid and solid waste from your toilet and functions similarly to a septic tank. Installation of a new black water tank is not an easy task, but with a clear understanding of the RVs plumbing system and the manufacturer's instructions for the black water tank, the installation task can be completed in a matter of hours. Once the holding tank is installed, perform routine maintenance and flushing to reduce odor and keep the plumbing working properly.


Difficulty: Moderate

Things You’ll Need:
  • Screwdriver
  • Dump valve assembly
  • Tank monitoring kit
Step 1
Choose a plastic, polyethylene or ABS black water holding tank. The black water holding tank must comply with the specifications and measurements outlined by the RV manufacturer. Travel needs also determine tank size, since the size of the holding tank will determine how often it must be emptied.
Step 2
Determine the location where the holding tanks will be installed. The toilet must be positioned right over the black holding tank. A straight run is necessary so the toilet empties directly into the black tank. Place the gray tank between the shower and the sink. A central location is necessary for the freshwater holding tank, so it is easy to hook up the shower, sinks and toilet.
Step 3
Install the water pump between your freshwater plumbing and freshwater tank, so the freshwater is pressurized (i.e., water that is delivered to the faucets, shower and toilet.) You will need to follow the manufacturer's instructions regarding the exact type and size wire is required for your specific water pump.
Step 4
Install sensors to the tanks so you know when it is time to dump the tanks. Attach the contact points, which are marked as "empty," "1/4," "1/2," "3/4" and "full", to the appropriate tank indicator line. You can find the indicator lines on the side of the tank. Lead the sensor cables from the tank and attach to the "panel 1" socket. Mount the display module and then turn on the sensors.

Tips & Warnings

Flush the black water holding tank as needed to reduce odor.
Mount the water pump per the manufacturer's instructions. Pressurize the freshwater by mounting the pump between your freshwater plumbing and freshwater tank. The manufacturer's directions will outline which type and size (gauge) of wire is required.
Mounting a holding tank varies from unit to unit.
Use this article as a general guide and refer to the manufacturer's guidelines for more detailed instructions.

Article Written By Charlie Gaston

Charlie Gaston has written numerous instructional articles on topics ranging from business to communications and estate planning. Gaston holds a bachelor's degree in international business and a master's degree in communications. She is fluent in Spanish and has extensive travel experience.

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