How to Winterize an RV

Three Parts:Draining the Water and Drying the Water LinesAdding Antifreeze to the Plumbing SystemCompleting the Final Details

If you enjoy camping but take to an RV rather than a tent, then you know there’s work to be done at the end of the camping season. When you’re done camping for the year, and it’s time to leave your RV dormant for the winter, you need to take the appropriate steps to winterize an RV. You don't want to find burst pipes come spring!

Part 1
Draining the Water and Drying the Water Lines

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    Allow all water to drain from the fresh water holding tank. To drain the water from your RV, you'll need to open what's called the "petcock." Do not be tempted to drain the water heater yet -- that has to be done after you add antifreeze.
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    Drain the black and gray holding tanks. You should also flush both tanks at this time.
    • If your RV does not come equipped with a built-in system, you should clean the tanks out with a wand or a product designed to clean both of the tanks.
    • Take all the tanks' contents to your local dump station.
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    Open any cold and hot water faucets in the RV. That includes those for the sinks, toilet and shower. If you don't, air can't come out the other end!
    • Flush your toilets a few times to make sure all the water's gone!
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    Attach a compressed air adapter to the RV’s water lines. This is commonly known as a "blowout plug." It can be purchased at all hardware stores and probably even your local Wal-Mart.
    • Technically, it's attached to the "Water Intake Fitting."
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    Use a standard air compressor, such as one used to inflate tires, to blow air through the water lines. The air from the compressor will force any remaining water out of the lines. This isn't 100% necessary, but it helps to keep your antifreeze from becoming diluted.
    • Pressure should be 30 pounds per square inch (maximum of 50 psi).[1]
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    Replace caps on all the drains, and close all the cold and hot water faucets. Reclose your petcock, too.
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    Detach the compressed air adapter from the RV. And the compressor along with it!

Part 2
Adding Antifreeze to the Plumbing System

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    Choose your method of adding antifreeze. There are three ways to do this:
    • From the inside using a water pump conversion kit
    • From the outside with a hand pump
    • With or without a bypass
      • We'll be addressing the water pump with a bypass method. The science behind the pumps is the same. However, without a bypass, you just have to add much, much more antifreeze. Regardless of whether or not you have a bypass, do not drain your water heater before adding the antifreeze.
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    Disconnect the water line that connects the fresh water tank to the fresh water pump. Attach the pump upstream of the water tank. That is, the antifreeze will go in before the tank.
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    If possible, bypass your water heater. This will save you gallons and gallons of antifreeze. You don't have to do it, but it makes everything much simpler. A few RVs have them built in, but most do not. To bypass your water heater:
    • Turn off the water heater
    • Disconnect the water supply (the above step)
    • If installing for the first time, disconnect the hot and cold lines going in and out of the water heater
    • Connect the bypass, following the instructions on the package
    • Close off the same hot and cold lines and open the bypass
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    Place the disconnected end of the water line in a jug of RV antifreeze. That's the pink kind, not the green kind. The pink kind is RV antifreeze, which is GRAS -- generally regarded as safe. The green kind is toxic. Not that you'd be swallowing any, but, you know, just in case.
    • Approximately 2 to 3 gallons (7.6 to 11.4 liters) of antifreeze should be enough to fill the RV’s entire plumbing system, provided a bypass is installed. If you don't have one, you need as much antifreeze as the water heater can hold, usually 6 to 10 gallons.[1]
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    Turn on the fresh water pump, and allow it to run as it pulls the antifreeze into the plumbing system of the RV. Alternatively, as discussed, use a hand pump connected to the city water hookup.
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    Start from the highest and work to the lowest point in the fresh water system. You'll probably start at the kitchen sink -- turn on the hot faucet and run it until it turns pink -- that is, filled with antifreeze. All the water has been flushed from the system! Then, run the cold faucet until it's pink, too.
    • The general order is kitchen sink, bathroom sink, shower, toilet, and outdoor shower. Run each of these until you see a strong shade of pink in each.
      • You may need to flush the toilet several times until the RV antifreeze comes out at a steady rate.
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    Pour about 3 cups (.72 liters) of antifreeze into the toilet and in each drain. This includes the washing machine, ice maker, and outside shower! Don't forget about those. The specifics of your RV will need to be taken into account here. Refer to your manual for more specific guidelines.
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    Take the water line out of the antifreeze jug, and reconnect it to the fresh water tank.
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    Locate the water heater, remove the plug and drain it. This is always done last.[2]

Part 3
Completing the Final Details

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    Remove all food, laundry, and valuable items. Kind of a big duh, huh? The last thing you want is an exploded two-liter of orange soda all over your fridge. Not to mention mice and ants.
    • And as for valuable items, why would you leave them in an RV for six months? And the laundry, well, it's just best to leave everything clean so when you come back in the spring, there's a lot less work to do.
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    Fix anything that's broken. Your RV is going to be sitting and stewing for a while -- not good for any machine (or human for that matter). To make sure it makes it through, fix everything now. You'll be glad you did.
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    Cover all vents and holes. Hopefully you already have some type of mesh guard for your exhaust pipe and whatnot to protect against mice, but make sure all the vents and holes are covered now. You don't want birds (think of the roof), rodents (pipes), or bugs (seams) making your RV home.
    • Check the entire RV for places that bugs or animals may be able to get into. Just because you're not using it doesn't mean they should get to!
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    Take the weight off the tires. If you leave that much weight on the one side of the tires, they could grow weak over time. So leave your RV on blocks, taking the pressure off the tires.
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    Cover it with a breathable material. While you don't want snow and rodents getting into your RV, you also don't want mold and mildew to start growing underneath your tarp. So if you do cover it, cover it with a material that breathes.
    • You may want to put rags on top of the sharp corners of your RV so that breathable material doesn't rip. For good measure!


  • Most RV parts stores will have the supplies needed to winterize an RV.
  • Your owner’s manual will have information about the preferred method of winterizing your particular model of RV.


  • Never use automotive antifreeze in the lines of an RV, as this can cause damage to the plumbing system.
  • Be sure to open the pressure relief valve when draining the water heater. Allowing the water to drain while it is under pressure, or hot, can lead to injuries.

Things You'll Need

  • Pump (water or hand)
  • Bypass kit (optional)
  • Antifreeze (minimum 3 gallons)
  • Tank-cleaning wand
  • Tarp of breathable material
  • Air compressor
  • Adapter ("blowout plug")

Article Info

Categories: Recreational Vehicles