The simple guide to winterizing an Airstream

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?

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.

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.

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?

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.

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.

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.

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

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!

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.

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?

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).

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

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.

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.

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.

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.

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!

Newbie here. We got a 2021 Globetrotter 23FB last spring, so first winterization coming up this weekend (ahead of sub-freezing temps predicted here in Nashville next week). The rig has a tankless water heater, but how do I know whether it’s acceptable to use RV antifreeze in it versus bypassing the heater and just draining it? Also, any suggestions on which RV antifreeze to use?

Hi Rich! Thank you for taking the time to run these blogs, I really appreciate it. I live in Colorado. Why do we need to draw antifreeze into the water lines if we have been really careful blowing all the water out of the water lines and low point drains with an air compressor?

Thanks Rich. About use in winter: it sounds gross, but a large heavy duty bag in toilet. Bring bottled water. When done camping, we take batteries home and place on trickle charge for a week and then once a month. I also inflate tires ~5 pnds over what I normally run them in case presure drops during winter. In spring I usually let a little air out. I’m in the no anti freeze in water lines camp. I really spend a lot of time doing that. U “know” my Airstream.

Steve Wood: Tankless water heaters don’t have bypasses, so the only winterization technique is to drain it and/or pump in anti-freeze. I recommend using anti-freeze so that you’re sure there’s no water left inside.

We don’t have a recommendation for a particular RV Anti-Freeze brand; they’re all about the same.

Richard Kovash: If you’re sure that you’ve gotten all the water out with your compressor, you don’t have to pump in Anti-Freeze. But if you’ve missed a little bit in the water pump, toilet valve, sink faucet, or other sensitive spots, you may find those items leak or don’t work in the spring! We (and Airstream) recommend Anti-Freeze because it adds redundant protection.

RV Tips and Travels on YouTube has great videos on both the compressed air method and the antifreeze method:
https://www.youtube.com/watch?v=luBM8Ml6Ezs
Blowing air into the fresh tank fill pushes much more water out the tank drain than gravity alone. Also a good tip is to blow air into the winterizing hose to blow out the water pump and the line after it. Turn the pump on briefly while you do it. Don’t forget to empty the strainer cup, too. I also blow out my black tank flush line. When I opened the cap there was water there, so now I leave it loose enough to drain. Add some antifreeze to your p-traps and black and gray tanks, too.

I’ve researched these questions and it’s not at all clear what the correct answers are. The airstream has 300W rooftop solar and is stored outdoors, the temperature gets below freezing but rarely/never below -15F I’m winter. (1) It’s not clear if I’m supposed to disconnect the negative battery terminal cable on lithium iron phosphate batteries when winterizing or if the batteries should be removed and placed in a warmer location. (2) If the battery is disconnected or removed do I need to do something about the current coming from rooftop solar (by disconnecting the solar panels on the roof)?

Steve C: Your LiFePO4 (lithium iron phosphate) batteries won’t charge below freezing, and eventually parasitic loads will drain them during winter storage if they are left connected. For that reason, you should make sure the batteries are fully charged at the end of the season, and then disconnect the negative cable when winterizing. This will eliminate any possible drain on the batteries, and they’ll be fine all winter.

People with lead-acid batteries (including AGM) should consider removing the batteries and putting them somewhere warmer (like a garage) for the winter.

You don’t need to do anything about the solar panels.

For more, you can read these articles:

https://battlebornbatteries.com/faq-how-to-winterize-your-batteries/

https://www.airgear.store/blogs/airstream/why-are-my-batteries-dead

Such a helpful board- – thank you!
Despite wintering in AZ, there are still overnight freezing temps! In your book, Complete Guide to Airstream maintenance, you mention “field winterizing” . Perhaps this is obvious, maybe disconnecting H2O hose & keeping furnace on, but is there anything else you might do to tide the TT over for a night or two in below freezing temps? Thanks in advance for any/all observations, information,
clarifications.

One possible storage option I have is inside but no climate control. There is some shore power available (not sure amps). How do I connect to trickle charge? Or better to disconnect? ( factory panels an BattleBorn batteries. I understand these have built in battery heaters.

Larry Wyman: Lithium batteries won’t charge at freezing temperatures, but if your storage goes above freezing regularly, then you can plug in the Airstream and the built-in charger will do the rest.

If you want the batteries to charge even below freezing, then turn on the built-in battery heaters. Just keep in mind that the Airstream must be plugged in, or you’ll drain the batteries instead of charging them.

Rich, my 2020 23’ ft twin Globetrotter required dealer to cut access hole (covered with fake furnace duct) for bypass valve. I notice that after closing bypass, I still get antifreeze in hot water tank. No leaks and hot water is fine during camping season. Could bypass valve not be closing? Access is limited in there.

Kevin, we have the exact same trailer and encountered the same problem with accessing the bypass valve. In our case I simply ignored the bypass and plumbed in an entirely separate winterization bypass (with PEX) in the water heater compartment. This was a big job, but it solved the problem: we can now bypass the water heater with easy-to-reach valves.

In your case I can’t be sure what’s happening, but your theory sounds likely. Antifreeze should not be getting in the water heater tank when the bypass valve is fully closed.