Hot water problems - Thermostatic Mixing Valve - 2021 Tab 400

PymburPymbur Member Posts: 6
I know this be has been discussed numerous times before, but I’m looking to start a thread specifically for the 2021 models. I’ve read as many other threads as I can find, but the solutions don’t seem to match up for my 2021. At least not what I’ve been able to find. 

I have hot water in the kitchen sink and bathroom sink. 
My shower hot water is scalding hot for 5 seconds, then straight to frigid cold.  

My mixing valve is turned as far as it can go.
I’ve seen the other threads here about removing a screw etc etc, but my mixing valve doesn’t look like the ones in those posts. 

Comments

  • BaylissBayliss Member Posts: 1,299
    edited April 2021
    @Pymbur, I don't have the new Speedfit "Thermostatic Mixing Valve" (TMV), but if you have not already read it, start with this discussion thread:

    https://tab-rv.vanillacommunity.com/discussion/comment/159795#Comment_159795

    Also, I copied the below info from an earlier post regarding adjusting the TMV.  It was posted by @pthomas745, but he pulled it from the T@B Facebook group, so if he has anything to add, he will likely chime in:

    Message from nuCamp: 

    We are just checking to see if you were able to resolve this issue.

    If not, please try the following:  Remove the red cap from the mixing valve, turn it upside down and use it as an adjustment tool.

    Turn the spindle clockwise to lower the mixed water temperature.

    Turn the spindle counterclockwise to raise the temperature.

    If you need any additional information, please contact our Customer Service department at 844-823-9112 EXT 834.  We hope that helps!

    Link to the Alde page:

    https://www.alde.us/news/new-product-alde-speedfit-mixing-valve/

    2019 T@B 320 S Boondock Lite2007 Toyota Tundra 4x4
    (Alde: 3020; Refrig: Isotherm Cruise 65 Eleg; Battery: BB 100Ah LiFePo4; Solar: Renogy 100Ah Suitcase; Victron BMV-712; Pwr Cntr: PD-4135KW2B; EMS: PI-HW30C)
    Greg & Marlene (Tucson, AZ)


  • pthomas745pthomas745 Moderator Posts: 3,641
    edited April 2021
    Nothing to add from what is already in that thread.  I know that photo is hard to read.  Maybe this link to a .pdf will be more readable? 

    2017 Outback
    Towed by 2014 Touareg TDi
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    edited April 2021
    @Pymbur - please check your Alde Flow pump.  Both the Alde pump and Flow pump should have the same settings - 2 or 3.  Do not try to adjust them from the display as that function is not engaged.  After you do this, wait an hour, then check it.  Also restore the air cushion in both the Alde and Flow tanks by briefly depressing the Safety/Drain valves.  Please let us know what happens.
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • Denny16Denny16 Member Posts: 5,445
    edited April 2021
    It is possible the mixing valve might be defective?  The OP is getting Luke warm water to scalding hot. This sounds like the vale is not consistently mixing the cold and hot water together.
    Cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Denny16Denny16 Member Posts: 5,445
    Nice summary of the system.  Thanks.
    cheers
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    @Pymbur - how did you resolve this?
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • DisenchantedDisenchanted Member Posts: 7
    I have gone from loving my 2021Tab 400 to baeelyliking it.  On my current trip, the batteries have failed due to overcharging, and y thermos mixing valve will not deliver Hot water insistently no matterhowiadjust it, even after following the great advice above.  My Aldiworks fine and is making hot water, but if I turn on the pump, cold water overpowers the hot.  My nautilis valves are set correctly for dry camping, if I leave the pump off hot water makes it to the sinks and shower but as soon as I turn the pump on it all goes cold, even with TMV set to one or 2 or 3 turns open.

    Tomorrow I will stop in Flagstaff for a new battery, but if I spend a good chunk of each trip troubleshooting unreliable NuCamp complexities, the allure of the Tab fades fast.

    Any new ideas on the TMV or should I replace it when I get home?  Anyone else destroy a battery due to overcharging when hooked to shore power?

    Thanks in advance, Disenchanted Tab 400 owner
  • MuttonChopsMuttonChops Member Posts: 1,587
    @Disenchanted ; Hopefully you are just enduring initial use issues/part failures.  As when the Adle is working well (which is most of the time) it is a wonderful cabin and water heat source.

    I find the Mixing Valve difficult to adjust as the process and instructions are confusing.  Carefully revisiting the 'how to adjust' instructions in the manual might help.

    And of course like at home you need to wait for the 'older cold' water to clear the lines before getting hot water, taking Sea-Showers as I do means more time for the lines to cool & more cold water shocks.  The Alde tank is limited to ~two gallons and even with the 400's extended hot water feature you might be demanding more hot water than available.

    Some owners (few and far between) have reported defective Mixing Values from the factory.
    You can also disassemble the mixing value to replace internal parts or confirm everything is normal.
    As for the Battery being damaged from over-charging.  You maybe first to report that.  It would be a very rare situation . . . are you confident overcharging is the cause?
    Is the WFCO power center set to the correct Battery type AGM/Lithium ?
    If Lithium, those batteries have an internal Power Management System . . perhaps you have a Bad from Factory battery.

    Does sound as if a Service Department conversation if not visit would be helpful.
    '18 320 Spitched axle, 3020HE; PNW based
    TV: '17 Colorado V6 Z71 4x4, Tow Package, GM Brake Controller
    Adventures:  51   Nights:  322  Towing Miles 41,200+
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    edited April 2023
    @Disenchanted - I believe you have the Thermostatic Mixing Valve.  It sounds like you have followed the above advice from backpacker47.  It is very frustrating when you simply want hot water.  You mentioned that you get hot water at your sink and shower, but the water pump prevents hot water.  So, does that mean you are you getting hot water when you are hooked up to city water?  Just to make sure, are you disconnected from city water when you run the pump?  

    Also, please start a new thread regarding your battery.  There have been known cases of premature battery failures with the Harris batteries.
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • DisenchantedDisenchanted Member Posts: 7
    @Muttonchops - great diagram... can you provide a link to the source... or tell me what 2 and 3 are? Thanks, i'll try to take this apart today.  

    @Sharon_is_SAM - I was boondocking, nautilus in dry camping alignment.  After all adjustments failed me, i experimented.  IF i turned off the pump and just used residual pressure, with the faucet in the hot water position, the water would turn warm at the faucet.  Then i would shut the faucet, run the pump until it stopped (build up system pressure), turn the pump off and open the faucet again.  Using that method:
    a.  I could confirm the alde readings... there was hot water
    b. I could eek out enough hot water to wash my face or with repeated cycles get a warm sea-shower.

    but if i left the pump running, the cold water seemed to overpower the hot water at the mixing valve and only pass cold water.  

    It worked fine for my first two seasons of camping, but has eluded me this season.  I plan to replace the TMV and see if that fixes the problem.  

    THANKS to all for your input
  • MuttonChopsMuttonChops Member Posts: 1,587
    Disenchanted said:
    - - -  great diagram... can you provide a link to the source...
    Diagram is from the LK 550 AquaMix mixing valve literature (attached).

    The LK 550 was noted by at least one forum member has the make/model used in their system.
    '18 320 Spitched axle, 3020HE; PNW based
    TV: '17 Colorado V6 Z71 4x4, Tow Package, GM Brake Controller
    Adventures:  51   Nights:  322  Towing Miles 41,200+
  • DisenchantedDisenchanted Member Posts: 7
    Update:  I took my TMV out of the trailer - the John Guest Push Fit connectors are actually pretty easy to undo - press the black elbow and white collet into the TMV, hold the collet against the brass and pull the fitting (elbow) out.  Worked for all three joints.

    Took the valve apart on my workbench. Found a crushed o-ring, and the hot water check valve seemed stuck so i removed the screen and exercised it several times... and put it all back together... It now works like it is supposed to, but the water temp never goes above lukewarm, but it stays at lukewarm with the pump running!! i could live with that, but wife likes hotter water so going to buy and install a new valve since it is so easy to install.  A couple pics below... Oddly, my best support came from an Airstream dealer - Airstreams have Alde units too.  My Nucamp dealer was useless, had no parts in stock, and advised it was very hard to order parts from Nucamp.  The Airstream dealer placed the order for the new TMV while i was on the phone.  If you are ever in a pinch it is useful to know that airstreams have alde units and parts too. 
    Unit disconnected at the John Guest Push Fittings:
     
    Parts (disassemble with 3/4 inch wrench) top row is from main body, lower row is from the hot side connector (collet with sharkbite teeth, o-ring, screen retainer, screen) Also pictured is the crushed o-ring

    Reassembled valve with new o-ring

  • MuttonChopsMuttonChops Member Posts: 1,587
    Disenchanted said:
    . . . Took the valve apart on my workbench. Found a crushed o-ring, and the hot water check valve seemed stuck so i removed the screen and exercised it several times...
    Excellent!  Looks like you have found the 'root cause'.
    Now, is your mixing valve an LK 550 ?  - - -  pictures look like a different brand/model then used in earlier build-year Tabs - - -

    Disenchanted said:
    . . . Oddly, my best support came from an Airstream dealer - Airstreams have Alde units too.  My Nucamp dealer was useless, had no parts in stock .  . .
    Not the first time someone has made that observation.  Which is interesting since nearly all nüCamp units have the Adle while Airstream currently only has One Model of their large selection that uses the Adle.

    Perhaps it is due to Airstream dealerships being Airstream only.  While nüCamp dealers are just your average multiple RV Brand sales lot.

    I was looking at the Airstream Basecamps recently and was impressed with the knowledge and helpfulness of the dealership's Service Department . . . not a typical multiple brand dealer professionalism. (of course Airstream has all the same, everyday quality & materials issues of the NA RV industry)

    '18 320 Spitched axle, 3020HE; PNW based
    TV: '17 Colorado V6 Z71 4x4, Tow Package, GM Brake Controller
    Adventures:  51   Nights:  322  Towing Miles 41,200+
  • MuttonChopsMuttonChops Member Posts: 1,587
    edited April 2023
    Disenchanted said:
    . . . the John Guest Push Fit connectors are actually pretty easy to undo - press the black elbow and white collet into the TMV, hold the collet against the brass and pull the fitting (elbow) out.  Worked for all three joints.
    Thanks, I did not know 'the name' for those things. ;)

    For others (like myself) here's a video on how they work:

    Demo is at timestamp 1:09 'ish
    '18 320 Spitched axle, 3020HE; PNW based
    TV: '17 Colorado V6 Z71 4x4, Tow Package, GM Brake Controller
    Adventures:  51   Nights:  322  Towing Miles 41,200+
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    @MuttonChops - disenchanted has a 2021 400 with the newer style mixing valve that replaced the LK 550 valves in our older rigs.
    @Disenchanted - please update us regarding the hot water situation once you get the new TMV installed.  It really adds to our knowledge base when hot water issues arise.  I believe you were the first to report inadequate hot water when the pump was used.  When this is all repaired, I hope you can change your ID to Enchanted instead of Disenchanted😊
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • DisenchantedDisenchanted Member Posts: 7
    @Sharon_is_SAM Ha Ha... overall, we love our T@B... just wish the dealer and manufacture support was better, and there were not so many "surprise" issues at inopportune moments.  These forums do help us all be self sufficient and enable us to self service our amazing little rigs to overcome the dealer/manufacturer support gap.  Should get my new TMV from the Airstream dealer in about 2 weeks and will update then.  
  • PhilipddeanPhilipddean Member Posts: 6
    Any Update?  I am having a similar problem.  No way to get hot water without using the boost...  Every indication is the water is hot going to the mixing valve.  It is full hot and still no hot water without the boost.
  • pthomas745pthomas745 Moderator Posts: 3,641
    @Philipddean the year and model of your trailer will help.
    Have you adjusted your mixing valve?  Are all of your winterizing valves in the proper "camping season" position?  The bypass valve, etc.  (This is a year/model specific sort of question).
    Checked the outdoor shower faucets to make sure they are off?  The outdoor shower head off, too?
    The good news is you are getting hot water, just not "hot enough" on the non-boost setting.
    In the Alde service menu, have you looked at the water temperature readout there with the Alde in the "normal" hot water and the "extra/boosted" hot water positions?

    2017 Outback
    Towed by 2014 Touareg TDi
  • PhilipddeanPhilipddean Member Posts: 6
    pthomas745 Yes, I have done all the things you mentioned.  2022 Tab 400.  I get the same result whether Boondocking or city water.  I will order a new valve when I return home from this trip in about a month. Hopefully that will solve the problem!
  • DisenchantedDisenchanted Member Posts: 7
    I resolved my issue by purchasing a new TMV from the local Airstream dealer, installed it, and hot water functionality returned to normal.  The issue i was having with lack of hot water, appears to have been due to a faulty TMV
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,481
    edited June 2023
    Thanks for the update @Disenchanted.
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • PhilipddeanPhilipddean Member Posts: 6
    I am back and have finally figured out my hot water problem!

    We left a couple weeks ago for a 6-week trip.  I thought the problem may have magically fixed itself....not so.

    I tried everything to get hot water. We have a 2022 TAB400.  Here is what I did:

    1: Made sure the mix valve is full hot.
    2: Confirmed that the hot water pipe is connected to the correct side of the mix valve.
    3: Made sure the outdoor shower water valves are turned off.
    4. Made sure all the air is out of the system.
    5. I have tried both water from the tank using the pump and city water.
    6. Made sure the one-way check valve prior to the mix valve is correctly installed.

    What we got was a short(2 second) burst of hot water and then cold.  We have tried boosting, but it doesn't seem to help.  Boosting did seem to make a difference last year.
    Glycol temp is 156 and water temp is 149. It was higher when boosting.

    I contacted NuCamp and got the TMV part number and then Moix RV in Conway, Arkansas which was along our planned route.  Mason at Moix RV was a great help and had the mix valve overnighted to our next stop from the factory.

    30 minutes after receiving the part, we have hot water!!  Awesome.  I think the valve may have never functioned correctly, but no way to be sure.  I am just thankful to NuCamp and Moix for all their help in resolving this problem!!

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