TAB 400 Boondock 2021 Winterizing


After consulting NuCamp, Nautilus, and You Tube, I think I have condensed the previously confusing process of Winterizing this RV. There were vast differences from the 2020 model while, the 2021 directions have not yet been released.

I hope this makes it much easier for the next TAB 400 2021 Winterizer.

Drain Fresh Water Tank

Turn Water Pump on & open all Hot & Cold faucets & Outside Shower lines. Do these (one line at a time). When water flow stops turn pump off.

Open Low Point Drain Valves, Hot & Cold (one at a time) & close back up.

Open ALDE Pressure Relief Valves (2 and they are yellow) One is for the Hot Water Tank & one for the ALDE flow. I have provided a photo below for one line. The other is there, but not in the photo. Easy to locate under the right side of the bed.

Drain Waste Water System. Black first, then Grey.

Set Nautilus to Winterization Mode. Make sure Red Lever is Correct! This is the ALDE Bypass Valve.

Connect short hose to City Water Inlet. Insert other end into Antifreeze Jug. Open kitchen faucet & turn water pump ON. You can use either the inside or Outside Water Pump Switch. Pump winterizing fluid into each Hot & Cold Line (one at a time) until pink antifreeze appears. Pump the fluid through everything that emits water.

Final: Pour ¼ gallon into every drain & toilet. ½ gallon into shower drain.

Please peruse these procedures and let me know if I need to edit. I would certainly appreciate your comments and I’m sure all TAB 400 Boondock 2021 owners will benefit from our effort. 

Giota in Santa Fe



  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 7,805
    How about a picture of how the Nautilus should be set?
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • GbertrandGbertrand Member Posts: 38
    Thanks so much @Giota for the great post, I will be doing mine in a couple weeks if our weather keeps holding 😀😀😀😀
     2021 [email protected] 400 BD, 2019 F-150, or 2011 F-150 (depending on conditions)

    Definition of Success….”moving from failure to failure without any loss of enthusiasm” (Winston Churchill)
  • berggerbergger Member Posts: 349
    Before you put the levers completely into winterization mode to fill with RV antifreeze don't forget to place the levers in a 45degree position first.  When you do this a little more water will come out as this allows it to be release from the fresh water tank line.  Then put them into full winterization position and continue.  On a side note I had a little trouble getting my pump to prime at first.  I ended up having to pour antifreeze into the short hose and blow it into the pump.  Once I did that it worked great.  
    2021 [email protected] 400 BD  "Vixen Gail" 
    2018 Nissan Titan Pro 4X "Big Bird"
    Leadville Colorado
  • GiotaGiota Member Posts: 55
    Thank you, I primed the hose same way you did. The whole process only took 2 gallons of antifreeze. Was it the same for you?
  • runaway30runaway30 Member Posts: 81
    Giota, thank you for the instructions.
    The initial step to drain the fresh water tank is accomplished by opening each faucet one at a time until the flow of water ceases?
    Followed by opening the low point drains for the hot and cold water lines?
    Can you fill me in on the location of the low point drains for the hot and cold water lines.  I am sure I saw a picture of them somewhere but I cannot locate it now.

    I am receiving my new 400 in January!

  • williedeanwilliedean Member Posts: 11
    runaway30, Draining the fresh water tank and opening each faucet are two different steps. The first step is to drain the fresh water tank by opening a valve located under the trailer just to the rear of the driver side wheel.

    The valves for the two low point drains are accessed through the Nautilus. They are located right under the outside shower controls.

    General comment on priming the pump:
    For priming the pump, I did not need to blow into the hose. I did it by:
    1. Hold up the end of the short hose that is connected to the city water line
    2. Pour antifreeze into the hose until it was full.
    3. Turn on the pump. 
    4. When the pump starts pulling antifreeze out of the hose, stick the hose into the antifreeze container and let it run until the pump has pressurized the lines and the pump stops running. 
    5. With the pump switch still on, start opening  each of the different hot and cold water lines.

    2021 [email protected] 400 BDL (June 2020) - "Sojourner"
    2019 Jeep Grand Cherokee Overland V6 
    Cincinnati, OH
  • runaway30runaway30 Member Posts: 81
  • Cheryl13Cheryl13 Member Posts: 16
    edited November 2020
    Thanks for the great info.  We have a newbie question.  In the following :

    "Open ALDE Pressure Relief Valves (2 and they are yellow) One is for the Hot Water Tank & one for the ALDE flow. I have provided a photo below for one line. The other is there, but not in the photo. Easy to locate under the right side of the bed."

     which side of the TAB is the 'right' side?  Are you referring to the driver's side (next to the Nautilus) or the other side?  thanks--winter is upon us!

    2021 [email protected] 400
    2019 Subaru Ascent
  • ChrisFixChrisFix Member Posts: 643
    The Alde pressure relief valves are under the bed on the Driver's Side of the 400...or the Right Side if you are looking at the 400 from the front.
    After two years of looking and considering...finally the proud owner of a 2021 [email protected] 400 Boondock!
    2020 Honda Ridgeline RTL-E with Redarc Trailer Brake Controller
  • McfryMcfry Member Posts: 1
    @Giota, the info above is helpful.  We are heading home from our first trip in a 2021 [email protected] 400 and plan to store in a climate controlled space (cave).  2 questions: 
    1)can I follow your instructions above but stop at “Set Nautilus to Winterization Mode” ? and be ok for a few months?
    2)if it is drained, at what outside temp do I have to get it inside?  Will it be ok at 28 degrees for a few hours?  Looks like we may have a few nights hovering near freezing and then back to 40s and 50s.  We would like to keep it in the driveway until Monday but not sure about those temps without winterizing??
  • Fitzpats3985Fitzpats3985 Member Posts: 2
    Does anyone know where I can get the owners manual to the nautilus system on the 2021 tab 400? My dealer walk through was terrible and it’s not in the materials provided 
  • Cheryl13Cheryl13 Member Posts: 16
    We have found the unofficial TaB guide to be more helpful than the official  but old documents.  We did get Nautilus  documents.  The description above is the way to proceed with the 400 for winterizing. Just finished here in ohio in the nick of time
    2021 [email protected] 400
    2019 Subaru Ascent
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 7,805

    These are the only instructions available.  The Nautilus instructions will refer you to “Owner’s Manual” information, however, that is a generic reference that does not yield any new information as the nuCamp Owner’s Manual only has a brief mention of the Nautilus on pg 32.  Best advice is trust the above Nautilus instructions and come back here for questions.
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • Denny16Denny16 Member Posts: 3,399
    The owner’s manual does point you to the a Alde overflow valve under the drivers side of the rear bunk, you lift this to help finish draining the water from Alde and another one for the Flo tank.  All the other controls are on the Nautilus panel.  The Red valve handle on the Nautilus panel s the Alde By-pass valve, mentioned in the owner’s manual.
    2018 TaB400 Custom BoonDock, Jeep Gladiator truck, Northern California Coast.
  • KsublettKsublett Member Posts: 3
    Very informative.  I had an additional step (step 5) in my Nautilus P3 manual user instructions:  5. Using “City Water” inlet or low point drain, blow out plumbing lines (40 PSI max) with handles still at a 45 degree angle to ensure any trapped water in plumbing harness is removed.  6. Close drains on hot water tank and low point drains.  7. Turn handles to “Winterize” position…then proceed with your directions to connect short section of garden hose to inlet labeled “city water” to add Glycol.  Please let me know if step number 5 is needed.  I’m not sure if my Manuel is for the 2021 as it does not state a year.  Everything else is the same as you stated. 
  • Denny16Denny16 Member Posts: 3,399
    edited October 3
    Once the water lines are blown out, there is not any water left in them to freeze.
    Some TaB owners also add the RV antifreeze to get antifreeze protection in the various valves, like in the toilet on units that have a black tank, and some antifreeze in the black and gray tanks to get the stuff in the outside dumping/drain valves, which will freeze and can cause damage.  

    I just drain, blow out, and leave the outside dump valves open, so any residual water will drains out.  I leave the inside faucet valves open, to leave room for any pressure as any small bits of remaining water expands as if it feeezes, to relieve any pressure.  

    I do not add the RV antifreeze.  That said, I do not live in a hard freeze area, so doing both steps is up to you.  If you are in a hard freeze area, it does not hurt to add the antifreeze for additional protection.  Just ope the various valves, including the toilet flush valve and outside shower valves as you pump the antifreeze in, so you have the stuff in the valves.
    2018 TaB400 Custom BoonDock, Jeep Gladiator truck, Northern California Coast.
  • idacamperidacamper Member Posts: 6
    Did you leave the pressure valves open?
  • Denny16Denny16 Member Posts: 3,399
    @idacamper If you are referring o the Alde pressure relief drain valves, I close them once the water is drained/blown out, no need to leave them open, as any pressure build,up,in the Alde tank will release them.  I also close the low point drains after draining/blowing out, to keep bugs and other small creatures out.  Leaving the inside valves open is sufficient o release any pressure build up in the plumbing/pipes.
    2018 TaB400 Custom BoonDock, Jeep Gladiator truck, Northern California Coast.
  • pthomas745pthomas745 Member Posts: 2,244
    Question:  the Nautilus is very mysterious to me, since I've never seen one.  When I read the directions and look at the handle positions, I'm trying to match the handle positions for winterizing with the valve settings in the "older" plumbing (like in my 2017).  In my 2017, I close the valves on the hot and cold water lines to the Alde, and open the bypass. 
    So: are the handles on the Nautilus basically doing the exact same things?  The bypass I get.  Are the colors on the Nautilus handles associated with the hot and cold lines going to the Alde? 
    2017 Outback
    Towed by 2014 Touareg TDi
  • manyman297manyman297 Member Posts: 460
    @pthomas745 Having just run our winterizing procedure, I finally read the Nautilus manual and in the beginning few pages it actually calls out what each color handle does. Having that knowledge really helps me make sense of what is actually going on behind the scenes. 
    2021 400 BD
    2020 Tacoma TRD Off-Road 
  • pthomas745pthomas745 Member Posts: 2,244
    Thanks, I saw that, but it didn't compute:  so, in the simplified Nautilus system:  there is only one valve that prevents anything  (water/bleach/antifreeze) from going to the Alde:  the Red handle? 

    Compared to my 2017 plumbing, where I needed to "turn off" both cold and hot supply lines to isolate the Alde?

    2017 Outback
    Towed by 2014 Touareg TDi
  • Denny16Denny16 Member Posts: 3,399
    Correct, the Red Handle is the Alde cutoff valve on the new TaBs, for the 320 models, the valve handle is not part of the Nautilus, but is on the left side of the Nautilus compartment.  On the 400, with the larger Nautilus panel, it is the center Red handle on the Nautilus panel.
    2018 TaB400 Custom BoonDock, Jeep Gladiator truck, Northern California Coast.
  • CarsoncitysmithCarsoncitysmith Member Posts: 1
    This is a good write up.  We just did our 2021 400 with similar results.  I could not build up air pressure in the water lines with the compressor, but we did blow out a gratifying amount of water in the process.  We also needed to prime the pump by pouring antifreeze into the city water intake.  With blow out and running pink freeze through all the valves and drains I think we are ok.
  • GrandmasKidGrandmasKid Member Posts: 154
    We are traveling to Florida for the whole month of December but it may freeze a few times before then. The freezes will probably be light as we are in metro Atlanta, GA. I'm considering  using just a blowout method on our 2021 400 BD before we go. Is this advisable? To use this method would I just use Giota's method but not add the antifreeze? This is our first winter with our 400 and plan on doing a lot of in and out of freezing weather camping. We previously owned a 2017 [email protected] Outback and used the blowout method without any problems. Thanks for any advice you may give.
    2021 400 Boondock/ 2021 Toyota Tacoma Off Road
  • ColoradoSunColoradoSun Member Posts: 114
    All I can say is don’t forget to run the anti freeze through the toilet water line. It’s easy to forget.
    2021 [email protected] 400 BD, 2020 Toyota Tacoma Double Cab
    SW Colorado
  • 400newbie400newbie Member Posts: 3
    So, I am completely new to this, quick question, should there be antifreeze in fresh water tank too? and if so, how do I get that done. I followed above instructions and no antifreeze came out of the fresh water drain., thanks for your help
  • 400newbie400newbie Member Posts: 3
    what would be a good CFM value for a compressor for winterizing? thanks, new to this......
  • pthomas745pthomas745 Member Posts: 2,244
    @400newbie The compressor does not need to be big.  I have one of the smaller ViAirs that rates at about 1.07 CFM.  Does fine.  Once the water tank is empty.....there shouldn't be any issue with it freezing.  A little bit of water isn't enough to expand and cause problems.
    Here is a whole thread about compressors.  A quick search in the "search box" for compressor can give you a few more.

    2017 Outback
    Towed by 2014 Touareg TDi
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 7,805
    @400newbie - that’s the beauty of the Nautilus system.  You put AF into the plumbing lines without soaking the fresh tank with AF.  Makes the spring dewinterizing much faster with less water.
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
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