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Winterizing The Fresh Water System

Winterizing the Fresh Water System

Protecting the RV plumbing system from freezing is important to avoid costly repairs. Below is a list of a few items required and the procedures to perform this service.

  1. Two to three gallons of non-toxic RV/Marine Anti Freeze. Length and layout of the RV determines the amount required.
  2. A Tank Wand or a Built In Flushing System to flush the holding tanks if not already equipped.
  3. A Water Pump Converter Kit or tubing to connect to the Water Pump inlet
  4. A few basic tools to aid in installation and removal of drain plugs.

Read the RV owners manual to follow proper winterizing procedures for the recreational vehicle.


  1. Disconnect water supply.
  2. Remove and bypass any inline water filters.
  3. Drain the fresh water holding tank.
  4. Drain and flush the Gray and Black Water holding tanks.
  5. Verify the water heater is cold and turned off. Remove the drain plug and drain the water heater. Open the relief valve to aid in quicker draining.
  6. Open all hot and cold water faucets including the outside shower and toilet if equipped.
  7. Locate and open the low point water drains.
  8. Turn on the fresh water pump to help flush the remaining water out the lines. Turn it back off when water flow has stopped.
  9. Close all faucets and drains.
  10. Install the Water Heater Bypass Kit (if not equipped) and bypass the water heater. This is required to save many gallons of the non toxic Anti Freeze.
  11. Install the fresh water converter kit to the fresh water pump inlet or tubing as required, if not already equipped.
  12. Install the suction tube from the converter kit to the pump into a gallon jug of the Anti Freeze. Turn on the water pump and allow the fresh water system to pressurize. Periodically replace the antifreeze jug when the solution gets low. Starting at the closest faucet to the pump, slowly open the hot and cold valves until the colored Anti Freeze expels from the fixture. Close the valves. Continue this procedure for each fixture working away from the pump. Do not forget the toilet and outside shower, if equipped. If a washer machine and dish washer is in the unit, turn the units on in the cold and hot water modes to fill the valves with anti freeze.
  13. Consult the owners manual for ice maker winterizing techniques.
  14. Pour a cup of antifreeze down each drain and in the toilet to aid in preventing freezing of the drain lines and holding tank.


The RV is now completely winterized for the cold season.


See the article De-Winterizing to place unit back into service.