Forum Discussion

Bigbird65's avatar
Bigbird65
Explorer
Sep 16, 2019

Winterizing using an air compressor

Winterizing – Air compressor method – Minnie 2250DS
This is specific to our Minnie but applies to most RV trailers, the only difference is the location of the items listed. I have included photos of these items.

1. Start by draining the 3 tanks.

2. Open a water faucet. Turn on the water pump for about 20 seconds to run it dry.

3. On the outside of the Minnie drain the water heater by removing the drain plug or opening the drain valve, see photo. Lift the lever on the relief valve to vent air into the tank. Drop the lever when draining the tank is finished and reinstall the drain plug.

4. Bypass the water heater.

5. Put 35 psi air on the city water inlet and open each faucet in turn one at a time to blow out water until you only get air then close the faucet. Don’t forget the outside shower.

6. Open the toilet valve to blow out the toilet.

7. Open the low point drains. After 5 minutes, remove the 35 psi air.

8. Blow out the black tank blow down line by using the 35 psi air.

9. The fresh water pump has a filter on the inlet of the pump. Make sure there is no water in the filter. If necessary unscrew the clear cup on the filter and empty it.

10. Put some pink stuff (RV anti-freeze available at Wal-Mart) in the sink drains and lavatory drain and enough in the shower drain to get it to the gray tank discharge valve.

11. Also put some pink stuff in the toilet and flush to get it into the black tank discharge valve. Leave a little pink stuff in the toilet. Return the water heater to the normal or non bypassed condition.

12. Close the low point drain valves before the next camping trip. Also, fill the water heater by opening a hot water faucet with water pressure on the heater before the next camping trip and after all danger of freeze is gone.Do this before turning on electricity or propane.





  • Your process sound pretty compete and if it works for you that is great.

    The last time I tried air to blow the lines, I bought a city water/valve stem adapter, I set the regulator to 20 lbs. and proceeded to blow out the pump check valve.

    The air did forced the water through the lines and gurgled out the facet quite nicely, before the droplet on the pipe walls settled down into the low spots of the water line run when the air was removed.

    These days I drain the fresh water tank and the bypassed water heater and open the low point valves. While the water drains I go get a cup of coffee.

    With the water drained, I disconnect the fresh water line from the pump and plug in a 5 ft. length of clear tubing. (I got the fitting from TSC). I close the low point valves and drop the clear tubing into a gallon of RV antifreeze, turn on the pump and open the cold water facets till they each run about a pint of more of pink into the drain. I repeat with the hot water side.

    Finally, I go back and repeat the process with another pint or so of RV antifreeze from each facet.

    The five feet of clear tubing allows me to set the antifreeze jug in the middle of the trailer where I can see how full it is and when it need replacing. When I am done, I reconnect the fresh water line to the pump.

    Not counting the time to drain the water heater and water pipes, the process takes about twenty minutes and uses about 3 gallons of antifreeze, which ends up in the P traps and gray tank except for the antifreeze that goes down the toilet.

    We all have our winterizing methods that we developed over the years.
  • Grit dog wrote:
    Yup big bird. Pretty much how I does it too.
    Antifreeze only gets used in the drains and a little in the gray and back tanks. And I typically use windshield washer fluid for that and for winterizing my boats ballast tanks and pumps.
    Boat engine gets drained/blown out. Similar to the camper.


    Funny you say that, did mine today and I used window washer fluid for the traps too, first time doing that but didn't have any plumbing A/F, sposed to get down to -6*C, it was getting late and nearest store is a 40 minute round trip. :D
  • Yup big bird. Pretty much how I does it too.
    Antifreeze only gets used in the drains and a little in the gray and back tanks. And I typically use windshield washer fluid for that and for winterizing my boats ballast tanks and pumps.
    Boat engine gets drained/blown out. Similar to the camper.
  • I just blow the lines out, I found it took too long to completely flush the anti freeze outa the lines in the spring.
  • Bigbird65 wrote:
    Winterizing – Air compressor method – Minnie 2250DS
    This is specific to our Minnie but applies to most RV trailers, the only difference is the location of the items listed. I have included photos of these items.

    1. Start by draining the 3 tanks.

    2. Open a water faucet. Turn on the water pump for about 20 seconds to run it dry.

    3. On the outside of the Minnie drain the water heater by removing the drain plug or opening the drain valve, see photo. Lift the lever on the relief valve to vent air into the tank. Drop the lever when draining the tank is finished and reinstall the drain plug.

    4. Bypass the water heater.

    5. Put 35 psi air on the city water inlet and open each faucet in turn one at a time to blow out water until you only get air then close the faucet. Don’t forget the outside shower.

    6. Open the toilet valve to blow out the toilet.

    7. Open the low point drains. After 5 minutes, remove the 35 psi air.

    8. Blow out the black tank blow down line by using the 35 psi air.

    9. The fresh water pump has a filter on the inlet of the pump. Make sure there is no water in the filter. If necessary unscrew the clear cup on the filter and empty it.

    10. Put some pink stuff (RV anti-freeze available at Wal-Mart) in the sink drains and lavatory drain and enough in the shower drain to get it to the gray tank discharge valve.

    11. Also put some pink stuff in the toilet and flush to get it into the black tank discharge valve. Leave a little pink stuff in the toilet. Return the water heater to the normal or non bypassed condition.

    12. Close the low point drain valves before the next camping trip. Also, fill the water heater by opening a hot water faucet with water pressure on the heater before the next camping trip and after all danger of freeze is gone.Do this before turning on electricity or propane.







    I tried this method on my Diesel Pusher and also ran the pink fluid thru all the lines after the blow out. I found that I could just run pink thru the system only without any blow out and never had a break in 14 years, while living in Boulder, Colorado.
  • Yep, good step by step.

    I forgot the outside shower one year. Still need to replace it, because it definitely cracked that winter.

    Luckily it was just the showerhead and valve assembly that broke, and not the pipes leading to it.
  • Artum Snowbird wrote:
    Good one indeed.

    One very important point. Well before you begin, make sure the hot water tank is turned off. If there is any way air can get into the HWT when you remove the plug, a stream of scalding hot water can do serious damage.

    Very good point Mike. Thanks
  • Good one indeed.

    One very important point. Well before you begin, make sure the hot water tank is turned off. If there is any way air can get into the HWT when you remove the plug, a stream of scalding hot water can do serious damage.