Back Button

How to Replace the Plumbing in a RV

Ed English

Replacing the plumbing in an RV is very similar to replacing the plumbing in a standard residential home. It’s just a matter of removing the old parts and putting in the new. Replacement parts do not need to be RV-specific parts.

Aviod RV plumbing repair while camping.

Standard PEX plumbing pipe used in residential homes substitutes well for incoming supply lines whether hot or cold. Drain pipes can be standard PVC pipes used in residential plumbing. The only differences are the input will be to a fresh water tank and the outputs will be to two separate holding tanks with special adapters for connections.

  1. Turn off the water supply to the motor home. Empty the fresh water tank, black water tank and grey water tank.

  2. Disconnect the supply line from the sink, toilet or shower. Cut the pipe near the end to remove any connections. Look underneath the home and locate the other end of the pipe and any couplings in the line. Cut the other end of the pipe at the nearest coupling or tank entrance. Pull on the pipe to make it slide a little to check that it slides freely. Leave an end sticking up and tape securely to the end of the new PEX pipe. Pull the old pipe with the new pipe securely attached. Keep pulling until the new pipe appears at the coupling or other end of the pipe. Remove the tape and attach new connections with adapters.

  3. Disconnect the drain pipe from the fixture. Saw the pipe in half at the connector locations or anywhere along the pipe that will ease the removal. Remove the pieces and replace with standard residential PVC pipe and fittings. Use primer and glue to attach couplings at the various locations. Secure the pipes maintaining the proper drain slope to the motor home with nylon cable ties.

  4. Tip

    Special RV-type water heaters and toilets should be used for replacements. Proper one-way valves must be installed at all tank and toilet locations. Each section of supply pipe can be removed and replaced individually. Use as few connections as possible for each pipe section. Access to the plumbing pipe and connections may require removal of panels from underneath the motor home. Connections at fresh water tank and black water and grey water tanks can be adapted to attach to standard residential plumbing connections.


    Always take safety precautions and wear proper safety equipment while using hand tools.