As we are doing our short practice trips in Virginia in January and February, we’re getting good at winterizing and un-winterizing our Airstream. This is the list we use for reference, and while we are confident in the steps and haven’t broken our trailer yet after three unwinterize-winterize cycles, please verify the process for your own camper with your dealer.

Without further ado:

HOW TO WINTERIZE YOUR AIRSTREAM

(The Airstream used here is a 2016 International 27FB)

First we clear as much water from the trailer as possible:

1. Empty and flush the black and gray tanks
2. Turn off the water pump
3. If you have a water filter (ours is under the kitchen sink), remove it and reconnect the water line
4. Drain the fresh water holding tank. For our 2016 International 27FB, this is done by rotating a white-colored valve between and behind the two wheels on the driver’s side.
   
5. Open the low level valves to clear water from the lowest point in the lines. For our 27FB, these are two red-handled brass quarter turn valves just behind the forward driver’s-side wheel.
   
6. After they stop running liquid, close the black and gray tank valves and the two low level valves. You should now have essentially all of the water out of the system except for the hot water heater and a small amount of water in the fresh water holding tank. Go ahead and leave the fresh water holding valve open so it can continue to drip.
7. Bypass the hot water heater to ensure that none of the antifreeze gets in there (while it is safe for your pipes, it’s not for the water heater). To do this, look for a yellow bypass valve in a compartment in the bathroom close to the hot water heater. Ours is behind the lower panel under the sink. The valve should be inline; turn it perpendicular to the pipe to close it.
   
8. Next, we empty the hot water heater. MAKE SURE THE HOT WATER HEATER IS OFF AND HAS BEEN FOR AT LEAST AN HOUR. Then, open the hot water heater compartment on the exterior of the vehicle. This should be located on the bathroom side, near where the bathroom is (passenger’s side for our 27FB). Within that exterior compartment, there is a little white screw plug, and a gray metal floppy tab. The gray tab vents pressure from the tank, so unless you want your entire front to get covered in water when you open the plug (happened to me, luckily with cool water), pull the tab to ease the pressure. Unscrew the white plug to empty the tank of hot water. Leave that plug open and close the compartment.
   

Now we will fill the pipes and the drain traps with antifreeze:

RV Antifreeze is a pink liquid that is supposed to be harmless for humans. To run antifreeze through the lines, we will make use of the trailer’s water pump. You will need a short (2-3 feet) section of hose and a elbow screw-on connector (our dealer gave us the hose and connector–we recommend you consider this Pump Converter Winterizing Kit, which will give you the convenience of a valve, instead of building your own apparatus and screwing it on and off each time). You will also need two or three bottles of the pink antifreeze.

9. Locate your water pump. On our 27FB, it is in the two compartments below the wardrobe. On the water-in side, you should see a small filter attachment. Disconnect the hose running into the filter and attach your 2-3 foot section of hose. Put the other end of that hose into a bottle of antifreeze. 
10. Turn on your water pump. The pump should run for several seconds as it draws antifreeze from the container and replaces the air and small amount of water in the pipes throughout the trailer.
11. Next, go to each device that puts out water on your trailer – for ours, this is the kitchen sink, bathroom sink, toilet, interior shower and exterior shower. For each device, run the cold water until you get about two seconds of pink coming out; then switch to the hot water until you see the same. Note that even though we have bypassed the hot water heater, most airstreams are designed to mix a small amount of cold water in with the hot to increase output. For the toilet, just hold the flush down until you have two seconds of pink. 
12. If you’ve installed a valve a la the Pump Converter Winterizing Kit, rotate the valve back to its starting position so that it’s ready to pump water on your next trip (we’ve forgotten this step before and worried about a busted water system when the pump wasn’t producing water).

You are done! In addition to filling the pipes with antifreeze, you have also filled the drain traps by letting several seconds of antifreeze run down each drain, and the water that has run into the gray and black tanks with the line flushing has antifreeze mixed in.