Winterizing by blowout

I would love some help in reviewing what I’ve pieced together from a few different (sometimes confusing) sources about winterizing our new to us 2018 T@B 400.  We are using the blowout method and I would really like to have a clear step by step checklist, which is what I hope I’ve created.  I want to make sure I’m not missing a step or using an extra step. I appreciate extra eyes reviewing this: 
Blow out method Winterizing steps for 2018 T@B 400:
1. Drain fresh water tank (behind the driver side wheel, underneath the trailer), then close it.
2. Open the three low point drains (one is the water heater drain).  Access these to the rear of the driver’s side wheel, behind the access door.
3. Flip up the yellow Alde Safety Relief valve (access under the bed on the driver’s side)
4. Open all valves (two sinks, two showers).
5. Disconnect both hose fittings (on either side of water pump; see #A picture)—have a rag ready to catch the water coming out of the pump. Access this through closet.
6. Reconnect water pump hose fittings.
7. Connect compressor through city water connection.
8. Blow out the lines with air compressor at 30 PSI.
9. Wait until almost no water comes out.
10. Flush toilet twice while compressor is running.
11. Disconnect compressor air supply.
12. Close the three low point drains.
13. Close all valves (two sinks, two showers).
14. Flip the yellow lever  (Alde relief valve) down.
15. Pour some RV antifreeze down the sinks, shower drain, and toilet (about one quart total).
16. Drain excess water from black and grey water tanks.


  • Denny16Denny16 Member Posts: 5,445
    Looks good, except you have 15 and 16 reversed.  You need to drain grey and blank tanks before adding antifreeze, then open the blac and grey tank drain valves (using a bucket) to get antifreeze in the drain slide valves.  
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    edited December 2020
    Not sure what you mean by opening the sink and shower “valves”?  You will need to unscrew the shower head and drain the hoses.  If you mean the faucets to drain them, I would close them after draining all the plumbing, then open them one at a time to blow them out.  Same thing with the low point drains. Definitely thoroughly blow out the toilet by holding the valve open multiple times until pretty dry.  Not sure if 400 owners raise and lower the tongue - maybe they will chime in.
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • ChanWChanW Member Posts: 3,158
    edited December 2020
    Yes, one faucet at a time. You want to allow some pressure to build in the pipes before opening each faucet (and low point drain valves) separately. It gives the blowout air more 'push', ie: it's moving faster through the single pipe it's blowing thru.
    Chan  -  near Buffalo NY
    2014 S Maxx
    2011 Tacoma 4cyl ... edit: 2022 Tacoma 6cyl - oh yeah! 

  • Denny16Denny16 Member Posts: 5,445
    Also do not forget the outside shower valves, which need to be opened and purged with air to clear out the water lines here.  If you can not get sir to come out, check the cut off valves under the closet floor access panel.
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • GrandmasKidGrandmasKid Member Posts: 159
     During the air compressor blowout I left the Nautilus in city mode but had the Alde Nautilus valve in the bypass position. City mode is the last way I used our T@B and I got all the water out while in city mode. Then I started worrying that maybe that wasn't the right way and saw where someone had the Nautilus valves at 45° while blowing out so the next day I hooked the compressor back up and tried to blow out that way. I couldn't build up any pressure that way. I'm not getting more water out so I think I'm good. Can someone say for sure what mode the Nautilus valves should be in while compressing and blowing out the lines? We have a 2021 400 BD.
    2021 400 Boondock/ 2021 Toyota Tacoma Off Road
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    edited October 2022
    @GrandmasKid - both the Nautilus and nuCamp instructions say to set the valves to 45, then open the fresh and low point drains, then blow out with valves set at 45.  

    It appears their intention is to blow water out through the low point drains not through the taps!  
    You are not the only one to complain about inadequate air flow when blowing out with valves at 45.  
    If you drain with Nautilus set at Powerfill, then blow out set at 45, I think the fresh tank pickup line as well as the line that feeds the pump will be empty enough that you can blow out with drains closed and set at City Water or Winterize with the red Nautilus valve set to bypass the Alde.

    Did you see the video?

    Here are the nuCamp instructions.

    While the Nautilus system instructions are generalized instructions, the following steps outline more detailed instructions for winterizing the fresh water & waste water plumbing systems in your camper:

    1. Empty all black and gray tanks into an appropriate disposal. They must be as completely empty as possible.
    2. Level your camper or tilt it in such a way that the water in the tanks flows toward the low point and tank drain openings.
    3. Turn the handles on the Nautilus Panel to Power Fill Mode.
    4. Open all drains in the unit:
    a. Fresh water tank drain
    b. Low point drains (Red and blue Alde drain valves)
    c. Hot water tank drain (Yellow Alde drain valve. Vertical position is open, horizontal is closed)
    d. Gray & black tank knife drains.
    5. Open all water fixtures.
    a. Sinks
    b. Toilet (Flush)
    c. Shower
    d. Exterior shower
    6. When water has stopped flowing from all openings, close the drains and fixtures.
    7. Turn the handles to a 45 degree angle as shown in the Nautilus Panel Winterizing Instructions.
    8. Connect an air hose to the city water connection. You will need an adaptor with a pressure gauge.
    9. When blowing out the system with air, DO NOT exceed 40 PSI pressure in the plumbing lines. Damage may occur to the inline water regulator and other plumbing components.  The freshwater tank overflow drain is always open, so the tank does not become pressurized with either air or water. The fresh water tank should never have more than 2 PSI pressure in it.
    10.Blow air into the system and, always keeping one drain open, open each fresh water drain one by one until no more water is released.
    a. Fresh water tank drain
    b. Low point drains (Red and blue Alde drain valves)
    c. Hot water tank drain (Yellow Alde drain valve. Vertical - open, horizontal - closed)
    11. When the water is all drained out of the lines and all openings are closed, turn off and disconnect the air hose.
    12. Turn the handles to Winterize mode as shown in the on the Nautilus Panel Instructions.
    13. Connect a short piece of garden hose to the Winterize inlet of the Nautilus Panel and place the other end into a non- ethanol based approved RV antifreeze. A short hose (cut off) will help the pump prime easier and sooner.
    14. Press the pump switch to activate the water pump. The pump will run till the system is pressurized and will kick on when fixtures are opened. Note that the LED indicator light on the panel will be lit if pump is powered.
    15. With the system pressurized and one at a time, open each water fixture until antifreeze appears, then close. Remember to turn to both cold and hot so both lines are protected:
    a. Sinks
    b. Toilet (Flush)
    c. Shower
    d. Exterior shower
    16. When all fixtures are protected, turn the water pump off and disconnect the hose.
    17. Pour one cup of the RV antifreeze into each sink and shower drain to protect the traps.
    18. Follow manufacturer instructions for winterizing the toilet.

    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • manyman297manyman297 Member Posts: 1,185
    On our 400 I feel like I get most of the lines blown out expect the shower line. I can always hear gurgling towards the base of the shower no matter what I do. I end up using antifreeze anyway so it doesn’t matter but it would be nice to get all of the water out. 

    What would be the harm in setting the nautilus to “city water” with the shower valve open and blowing it out with 40psi? It seems that having everything in the diagonal setting doesn’t allow enough air pressure to get some of the more troublesome lines. Or maybe it’s because my camper isn’t perfectly level?
    2021 400 BD
    2020 Tacoma TRD Off-Road 
  • Denny16Denny16 Member Posts: 5,445
    The diagonal setting is just to blow out the Nautilus manifold valves.  To blow out the water lines to the taps, you need to set it to city water setting from what has been discussed here.  So do both, water lines first, than 45- degree the valves and give it a second blast for the valves.
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • RobermcmRobermcm Member Posts: 34
    Where is the second yellow Alde drain valve in this set of instructions?  There are two yellow valves ‘in the Alde compartment, when the flow is installed at least. Which is the ‘pressure relief valve’? The cold water line valve? The yellow valve on the hot water lines is clearly the boiler and flow drain valve. 


    2023 Tab 400
    2015 Audi Q7 TDI
    Northern Ohio

  • pthomas745pthomas745 Moderator Posts: 3,641
    @Robermcm the Alde Flow has a separate Yellow Flapper Valve, but it is mostly there to drain the Flow tank. It should be on a red pipe coming out of the Alde toward that red Flow tank.  The "Famous Yellow Flapper Valve", which is the "Pressure Relief" valve for the trailer plumbing, is the Yellow Valve on the blue cold water line that goes into the main Alde tank.
    2017 Outback
    Towed by 2014 Touareg TDi
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