Airstream trailers left unused through the cold winter months require winterizing to prevent damage to their liquid systems. If you leave liquid in your trailer's system through the winter, the liquid will freeze, damaging holding tanks and hoses throughout the vehicle. In order to prevent this damage and to prepare the trailer for the winter months, you will need to drain all liquid from the trailer.
Locate a local dump station where you can drain your Airstream water and waste tanks. Drive the trailer to the dump station and park it near the dump station's sewer holes. Level the trailer and then turn off the hot water heater and water pump.
Drain both the fresh water and hot water tanks by opening the hot and cold water taps on all water sources, including the shower. Open the low point drain line beneath the trailer. Press and hold the flusher on your toilet to drain the unit. Drain any appliances that contain water and then drain all water filter canisters attached to the system. Reattach the empty canisters. Close the line and taps after draining.
Remove the 1 ¼-inch waste drainpipe traps from beneath the trailer by using an adjustable wrench to remove the two nuts holding them in place. Pull the U-shaped traps from the trailer and empty any liquid within them. Replace the traps.
Close both of the valves located on your water tank, and then remove the holding tank outlet cap. Attach the three-inch sewer hose to the tank outlet and screw it tightly into place. Uncover the dump station's sewer hole and run the other end of the hose into it, extending the hose about six inches down the opening of the sewer connection.
Open the black tank valve to empty the sewage tank. Wait for the flow from the tank to end and then close the valve.
Open the grey tank valve to empty the grey water tank containing the dirty tap water. Wait for the flow of water to cease and then close the valve and remove the hose. Replace the outlet cap. Lift the detached end of the hose and hold it up slightly to drain any leftover water into the sewer.
Run some non-potable water through the hose to rinse it out and then pull the hose from the sewer. Rinse the end of the hose with the non-potable water before returning it to storage. Return the cover to the dump station hole.
Add a cup of unflavored, non-toxic RV antifreeze to all water drain traps and to the toilet.
Fully charge any batteries present in the RV (using an electrical outlet) to prevent their freezing during the winter.
