How to Winterize your RV with Air


  • A compressor capable of maintaining 100 PSI minimum output
  • City water inlet hose thread to air hose quick connector adapter
  • ½" drive ratchet with long extension and sockets
  • One gallon of non-toxic antifreeze
  • Shop towel or rags to wipe up splattered water
  • Channel lock pliers

Step 1: Drain the Fresh Water Tank

  • To find the drain, first locate the fresh water fill
    • The fresh water will be inside the trailer at the point of fill
    • Some RV's have sub-floor water tanks, but they will always be located by the water fill location
    • If your tank is inside your RV, the drain may be at the base of the tank, on the outside of the RV below the water fill or perhaps under the RV on a stanchion coming down through the floor
    • If the water tank is in an insulated sub-floor. The drain will usually be located on the bottom of the tank under the RV
  • Open the drain and let all the water flow out

Step 2: Drain the Water Heater

  • Turn off the 110-volt element in your water heater
    • Switch the wall switch AND the switch on the water heater itself to the "off" position
  • Locate the drain plug
    • Usually on the bottom of the tank, inside the water heater access door, on the outside of the RV
    • Using your 1/2" ratchet drive, remove the drain plug.
      • Drain plug will be either plastic or metal
      • Be sure to use the proper size socket on the drain plug, because some drain plugs are very tight
    • If your unit has a drain cock instead of a plug , it will look like an automobile radiator drain
      • Turn the drain CLOCKWISE to open
      • Pull the "pop-off" valve to the straight-out position
        • "Pop-off" valve is the brass valve at the top of the outside face of the water heater

Step 3: Drain You Plumbing System

  • Locate the low point drains if your RV is so equipped, and open them
    • To find your low point drains, follow your plumbing lines through your RV
    • The Drains will have pull-up "T" valves if they are in the RV
    • Some RV's have low point drains outside, under the unit
      • These outside drains will be either two 90-degree valves, or two lines with caps or plugs
  • Open all sink and shower faucets in the RV
    • This will allow most of the water in the system to drain
  • After all lines have finished draining, turn on the water pump and run it for five minutes
  • Check to see if your water pump has a filter screen mounted on the intake side of the pump
    • If your unit has a water filter, a winterize plug was provided at the time of purchase
      • Remove the filter and install the plug

Step 4: Blow out your water system

  • Connect your compressor to the city water inlet with the air-to-water hose adapter
  • Go through your RV and close all faucets and drains, leaving only the kitchen "cold" side open
    • Hang a damp wash rag over the faucet to reduce water splattering
  • When all water is blown out of the line, open the "hot" side of the kitchen faucet and close the "cold" and repeat
    • Repeat this procedure for the bathroom sink, the shower, the toilet valve, and the outside shower
    • Always leave at least one faucet open, so as not to build up excessive pressure in the water system
  • Remove the water heater drain plug and blow out any water that may have collected in the bottom of the water heater
  • Re-open the low point drains and make sure no water remains down in the stanchions
  • Replace the water heater and drain caps or plugs

Step 6: Antifreeze

  • To keep the sink drain traps from freezing, pour three cups of non-toxic RV antifreeze down each drain
    • Be sure to do all three; the kitchen sink, the bathroom sink, and the shower drain

Step 7: Drain Holding Tanks

  • Dump your black tank first, then the grey tank
    • Water in the grey tank helps flush solids and septic residue in the flexible hose line


  • Fill your water tank and run the water pump until water has recirculated throughout the entire water system
Save Your Batteries Over the Winter
How to Winterize your RV with Antifreeze
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