The simplest way to winterize your Airstream

Winterizing is the topic we all love to hate. It seems mysterious, complicated, and full of potential risk—and every fall the online forums and social media channels fill up with the question: "How do I winterize my Airstream?"

This happens despite the fact that there's already a ton of information on the Internet about winterizing.

I would argue the confusion is actually because there's too much information on the Internet, and much of it doesn't agree. Plus, most of it is not specific to models or model years. Even Airstream's own instructions (in Owner's Manuals, tech support articles, and webinars) sometimes diverge in confusing ways.

Winterizing doesn't have to be complicated. But the problem is that there's more than one way to do it, and generic checklists just won't get you there. The specifics of how to winterize vary according to which Airstream you have. 

For example:

  • Do you want to blow out the lines with compressed air, or use RV Anti-freeze?
  • Does your Airstream have a low point drain?
  • Are the tank water drains inside or outside of the Airstream, and what do they look like?
  • Does your water heater have a tank? 
    • If yes, does it have a water heater bypass?
    • If no water tank, which water heater do you have: Girard, Truma, Alde, or Timberline?
  • Does your Airstream have a winterizing kit installed?

You get the point.

With all these variables, there isn't just one set of steps to winterizing, there are at least 250 different possible versions! (Yes, I actually did the math.)

So, I've made things simpler.

For the simplest way to winterize your Airstream, I've made two key assumptions:

  1. You have a late model Airstream, which means it's equipped with a winterizing kit. And if you don't have a winterizing kit, I strongly recommend purchasing one–it makes things a lot easier and it costs less than $20.
  2. You're going to use the RV Anti-Freeze method, which I recommend instead of the air compressor method. 

    In addition, in order follow these simple winterization steps, you need to have your Owner's Manual handy, and be willing to refer to it to figure out where things are in your Airstream.

    With these assumptions and your Owner's Manual, you're ready to winterize the easier way.

    Tools and things you need to do the job

    • Two gallons of RV Anti-Freeze (the pink stuff, never automotive anti-freeze)
    • A wrench and Teflon tape, if your water heater has a tank (2021 and older)

    How to do it in 9 easy steps

    By following these 9 steps, winterizing will go from daunting to doable.

    I have a much longer discussion of this in my book, Airstream Life's (Nearly) Complete Guide to Airstream Maintenance, but this is the condensed version.

    IMPORTANT: You'll find the location and appearance of everything referenced below in italics in the Owner's Manual. So if you need help finding something on your own Airstream (like the tank drain valve), check the Owner's Manual. 

    Step 1. Dump the gray and black tanks.

    Step 2. Level the trailer.

    Step 3. Empty the fresh water tank. This requires opening the tank drain valves and letting all the water run out.

    Step 4. If your Airstream has a water filter installed (some 2016 and earlier models) remove the filter or bypass it. Then open the low-point drain and all the faucets and showers. This lets all the water in the lines out through the low-point drain.

    Step 5a. If your Airstream has a water heater with a tank, make sure it is off and the water is cool. On a trailer with a Dometic or Atwood water heater, remove the drain plug (water will pour out), open the P/T valve, and turn the water heater bypass valves to the bypassed position. The drain plug is best removed with a socket wrench and 15/16" socket (not an adjustable wrench). On a motorhome with a Suburban water heater, there's a red knob that acts as the drain plug.

    Step 5b. If your Airstream has a tankless water heater by Alde, Truma or Girard, you need to open the pop-off valve to let water drain out of the heater. Make sure the heater is off and the water is cool first. 

    Step 6. When water stops draining, close all the things you opened:

    • pop-off valve or P/T valve
    • tank drain valves
    • low-point drain
    • if you removed a drain plug, put it back in place with Teflon tape on the threads
    • shut off all faucets and shower fixtures

    Step 7. Turn the winterizing valve to the “winterizing” position so it is pointing to the clear plastic tube and remove the plug at the end of the tube.

    Step 8. This is the fun part. Stick the open end of clear plastic tube into a gallon of RV Anti-Freeze, and turn on the water pump. It will suck the pink anti-freeze from the jug and pump it to all parts of the plumbing.

    Open each faucet and shower fixture (including outside shower, if equipped) one at a time. Leave each fixture open until pink stuff starts coming out on both the hot and cold settings. Then close and move on to the next fixture. Flush the toilet until you see pink in the bowl, and also use the toilet sprayer (if equipped).

    While you're doing this, keep an eye on the Anti-Freeze. If it's getting low, shut off the pump and switch to the next gallon jug before continuing.

    When you're done with every fixture, turn off the pump, put away the Anti-Freeze, and put the winterizing valve and plug back the way you found them. If your water heater has a tank, leave the bypass valves in the bypassed position until you de-winterize in spring.

    Step 9.  Take care of the non-plumbing part:

    • Remove all food and items that might be interesting to rodents or insects
    • Remove anything that might be damaged by freezing
    • Disconnect the negative battery cable (the Battery Disconnect Switch is not sufficient) and/or remove the batteries to keep them charged at home
    • Make sure the refrigerator and freezer are empty and completely dry, and leave the door open
    • Add air to tires if needed
    • Put dielectric grease on the brass tabs of the 7-way plug.

    That's it! 

    18 comments

    Linda

    Linda

    What happens if you plan on using your AS during the winter for every other weekend camp trip? Do you have to go through this process each time before you take it out and after you come back? This is my confusion about “winterizing”. What is the winterization process for streamers who still want to be on the move a few times a month for a couple of days?

    Ric Jones

    Ric Jones

    I’ve been using this method of winterizing on 5 Airstreams over 22 years. Never had a leak in the Spring (touch wood). But one thing I always questioned: nothing in this method accounts for the water in the line from the fresh water tank to the pump. The fresh water tank is empty – but nothing is specifically dealing with any leftover water between the tank and the pump itself. Never had any issue but it seems like it could be a problem.

    Also an observation that many people with tankless water heaters now have a device called a shower miser. So that has to be dealt with. There is an extra line that goes from the faucet/valves on the shower and/or sinks back to the fresh water tank. Using RV Antifreeze to protect these lines would result in a little Antifreeze getting into the fresh water tank. I plan to just fill the fresh tank in the spring and then pump it out once or twice but it is a new wrinkle.

    Ken Williams

    Ken Williams

    I have a 2022 with a Girard Tankless Coil for hot water. The coach has what looks like a bypass valve, but I believe that the valve only allows the pump to pull in anti-freeze. I believe, but want to make sure, that the coil needs to be filled with anti-freeze to prevent damage – not just drained like a hot water heater with a 6 gallon tank.

    Cheryl

    Cheryl

    Have done the winterizing process as above. the question came up about how to get the antifreeze into the City water Intake? or maybe that’s not necessary after opening the low point drains…thoughts?

    Rich Luhr

    Rich Luhr

    Linda: In your case, you have 3 choices: (1) Re-winterize the Airstream between trips; (2) Store the Airstream somewhere above freezing; (3) Put a space heater in the Airstream between trips, assuming you have a power connection.

    Ric: If you follow the instructions as I’ve listed them, there should be little to no water in the line from the water pump to the tank. Any remaining drops won’t be enough to hurt the PEX plumbing. Regarding your second point: a little RV antifreeze in the fresh water tank isn’t a bad thing, and will quickly be displaced when you de-winterize in spring.

    Ken: These instructions take into account the Girard tankless heater. Girard says the coil does not need anti-freeze but it won’t hurt.

    Cheryl: Yes, if you drain the lines as described, there won’t be much residual water in the city water fill, so it should be fine.

    Tom Lowe

    Tom Lowe

    Why bother opening the pop-off valve in a tankless water heater when you will be pumping antifreeze through it? I’ve often made it a leaking pop off valve (RV or not) after messing with it.

    Rich Luhr

    Rich Luhr

    Tom: Opening the pop-off valve allows air into the tankless heater, which helps water drain out of it. It’s a practice recommended by Airstream, but you are correct that the anti-freeze will displace any water anyway. All of the steps regarding draining the lines are designed to make it easier to fill the lines with 100% anti-freeze. If you prefer not to touch the pop-off valve, just be sure that you’ve run plenty of anti-freeze through the tankless water heater.

    John Lange

    John Lange

    We have a 2018 Classic with the Alde water heater. Do you need to bypass it before pumping the antifreeze into the lines? Thanks!

    Jo Bode

    Jo Bode

    How do I know I have run enough antifreeze through the tankless water heater? I did run every fixture on both hot and cold position till antifreeze showed up. I did not let water out of the Girard tankless water heater pop-off valve … actually, where’s that valve located on my Flying Cloud 25 FBT? Thanks in advance!

    Rich Luhr

    Rich Luhr

    John L: There is no bypass installed for tankless water heaters such as yours.

    Jo B: Once pink/red anti-freeze comes out any of the hot water faucets, your tankless water heater is all set.

    Mark

    Mark

    Hi Rich
    Thank you for all the helpful articles!
    My question is regarding the batteries. I’ve got a solar panel that’s always charging them since it’s almost always sunny here. (Colorado)
    I’m thinking that I could just leave them hooked up?

    Rich Luhr

    Rich Luhr

    Mark: Sure, you can leave your solar panels connected all the time, as long as you’re not worried about theft. Make sure to check once in a while that the batteries are staying charged. The panels could become accidentally disconnected, or there might not be enough sun (or too much snow).

    Nancy

    Nancy

    How does this method account for the water remaining in the black tank flush?

    Rich Luhr

    Rich Luhr

    Nancy, the black tank flush drains down into the black tank, so most of the water is already gone just from gravity. There shouldn’t be enough water left in the line to cause a problem.

    Rob (Norton) McBride

    Rob (Norton) McBride

    Thanks for making it simple Rich. We are on Vancouver Island which is pretty moderate for Canada but you have offered some great suggestions. Best regards Norton Comox.

    Eric Rodriguez

    Eric Rodriguez

    I wanted to do the Anti Freeze method however the water pump on the 2022 20FB Bambi isn’t easy to find or use. It is in a compartment under the microwave however it is in a metal box(I presume since there nothing else there). The screws are very hard to access. Would be nice if they have a video showing how to access it in the box. Any comments will be greatly appreciated.

    Rich Luhr

    Rich Luhr

    Eric — the owner’s manual for your 2022 Bambi 20FB states: “The 20 ft. model has the pump and filter located under the microwave. The bottom panel below the microwave is held on by pressure catches. Remove this panel to get access to the water pump and winterization kit.”

    It sounds like no screws need to be removed. If you can’t figure out how to remove the access panel beneath the microwave, I suggest you call Airstream Support at 937-596-6111 for assistance.

    Eric Rodriguez

    Eric Rodriguez

    Thanks for your response Rich. I got to the pump however is inside a metal container with perhaps 15-20 screws. The book gives you the impresión that when you remove the panel the pump is exposed but it isn’t. I’ll will try Airstream Assistance, many thanks Rich!

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