Winterize Your RV Water System

If you are a fair weather camper than winterizing your RV water system is a must. When water freezes it expands, when it sits still on metal it rusts. The water lines and joints in a typical RV are not able to handle the pressure ice creates. The metal in your water pump (the bearings) will rust and seize the pump if they rust.

The winters in Oregon are fairly mild compared to other parts of the US. We usually have a week or so of below freezing weather, but not much more. If there isn’t any heat on in the inside of your RV, it doesn’t take too long for the RV pipes to freeze up.

The two common ways of winterizing the water system either involve compressed air or non-toxic anti-freeze. Which ever method you choose it is best to drain your hot water tank, and by-pass it.

1. Drain fresh water holding tank. (drain valve will be located out side the RV typically on the side wall, or underneath).

2.Draining the hot water tank

  • There is a nylon plug that unscrews near the bottom of the tank to drain it. Remember “Lefty loosy, righty tighty” It doesn’t take much to strip the threads of this plug.
  • Open a sink or shower hot water valve. This creates a vent for the water to siphon easily to drain all the water out of the tank.
  • If you have a hot water heater bypass installed, close off the tank after the water drains.

3. Option A (Compressed Air) purchase an air adapter that connects an air compressor line to the city water connection of your RV.

  • Turn on the 12 volt water pump (sink valves should still be open). Operate the pump until it runs dry.
  • Connect the air fitting to the city water connection.
  • Close all the faucet valves, except the farthest one.
  • Blow air into the city water line until water stops flowing. Close the faucet valve.
  • Open the next farthest valve repeating the process until you get to the closest faucet including the shower, and toilet.
  • Water is now out of the fresh water lines.

3. Option B (Non-toxic) Anti-Freeze. Use only non-toxic anti-freeze that is designed for RV water systems.

  • Pour a couple of gallons of the solution directly into the main water tank of your RV.
  • turn on the 12 volt water pump, and open individual faucets individually until all faucets are pouring out the anti-freeze.
  • Before using the fresh water system. It is recommended that you sanitize the system.

It is a good practice to pour a little of the non-toxic RV anti-freeze into the drains of each of your sinks and shower drain to keep the elbows from freezing and breaking over the winter.

4. Dump your grey water & black water holding tanks too.