How to replace pipe in an RV

Replacing the pipes in an RV is very similar to replacing the pipe in a standard residential home. It’s just a matter of removing the old parts and putting in the new ones. Spare parts do not need to be RV-specific parts. Standard PEX plumbing pipe can be used as a substitute for hot or cold supply lines. Drainage pipes can be standard PVC pipes used in residential plumbing. The only differences are the incoming will go to a fresh water tank and the leaving will go into two separate holding tanks with special adapters for the connections.


  1. Close the water supply to the RV. Empty the fresh water tank, sewage tank and dirty water tank.
  2. Disconnect the sink and shower supply line. Cut the tube near the end to remove the connections. Look under the house and locate the other end of the pipe and any coupling on the line. Cut the other end of the tube into the nearest coupling or tank inlet. Pull the tube slightly to make sure it slides freely. Leave one end and tape it firmly to the end of the new PEX pipe. Pull the old pipe tightly with new pipe. Continue pulling until the new pipe appears on the coupling or the other end of the pipe. Remove the ribbon and attach new connections with adapters.
  3. Disconnect the drain hose from the electric unit. Saw the tube in half at the connector locations or anywhere along the pipe that will ease the removal. Remove parts and replace with standard residential PVC pipe and fittings. Use glue to hold couplings in different places. Secure piping while maintaining proper drainage slope in the motor home with nylon flanges.

Tips & Warnings

  • Special RV water baths and water heaters can be used for replacements.
  • Appropriate one-way valves should be installed in all tank and bathroom locations.
  • Each section of the feed tube can be removed and replaced individually. Use as few connections as possible for each section of pipe.
  • Access to plumbing pipes and connections may require the removal of panels from under the motor home.
  • Connections in the fresh water tank and sewer and gray water tanks can be tailored to connect to standard residential plumbing connections.
  • Always take precautions and wear proper safety equipment while using hand tools