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  1. #1
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    2021 Momentum 381mr heat distribution

    Our first trip out this weekend in our 2 day old 381MR for my Daughters wedding and I was very disappointed in the heating system. Tried running the heat pump, seemed to do ok, not a lot of heat output. But when the temperature dropped down around thirty the first night the gas furnace kicked on, woke up sweating.In the master bedroom it was 88 degrees went into the main room it was 68 with the bedroom door open, the garage was 60 with the garage door open. Thought maybe I didn’t have something set right ,next day ,I tried going through it all again. Heat pump seems to work great during the day when it was just a little cool. Had heat pump selected as preferred source, fan on auto, heat only. By the way ,could not find any heat ducts in garage area? I read that there was supposed to be one in the 38MR, anyone know for sure?
    So ,
    The second night, same thing , woke up it was unbearable in the bedroom and cold in the main. We had to open some windows in the bedroom.
    I can only find one vent in the bedroom and one in the main bathroom (same wall behind sink) two vents under island in kitchen( same hole under island) and no other heat vents anywhere. ( None in garage)
    Is it normal to have such a huge discrepancy (20 degrees). I can deal with a small heater in garage ,but not the huge difference in the bedroom/ main room.
    Considered blocking the bedroom vent but think it could disturb air flow / pressure from the furnace.
    Maybe try and reroute it to under kitchen cabinets ?
    I may try and remove the false wall in basement and see what I can find under there.
    Really thought the heat pump would do a little better job than this, just doesn’t get very warm.
    We love this rig but very disappointed in the heating balance, any thoughts or ideas would be great.
    Anyone else have this issue and solved it?
    Thanks
    Camping with Joy
    Last edited by CampingwithJoy; 03-08-2021 at 08:36 PM.

  2. #2
    Paid my dues 😁 FT4NOW's Avatar
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    We had the same thing in our 399. My wife put a piece of paper under the duct in the bedroom. She took the plate off, put the paper in and replaced the plate. It was great after that. The garage should have a duct on the floor right in front of the bathroom, should look like metal with holes in it. The heat pump is ok, we mainly ran the fireplace and put a space heater in the garage. When it was going to go below freezing we would use the furnace.

    Sent from my SM-G950U using Tapatalk
    2021 Reflection 311BHS
    2018 F350 CC/LB/Firestone bags/Reese Goose Box

    SOLD - 2017 Momentum 399TH
    SOLD - 2016 F350 CC/LB/DRW/Curt Q24/Air Lift Load Lifter 5000

  3. #3
    Big Traveler geotex1's Avatar
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    Very common across the RV industry as these are very crude installations unlike residential and commercial installations where you have balance and supply and return paths for rooms. Your bedroom becomes a sweat box because you undoubtedly close the door. Some things you can do are to install an adjustable vent cover - easy direct replacement; get a dampner that fits the duct - out there but might need to visit and HVAC supply; and, either leave your bedroom door partially open or cut a vent in it.
    Rob & Nikki + Cloverfield
    2020 Grand Design Solitude S-Class 3350RL
    2015 RAM 3500 Longhorn Laramie Crew Cab, Long Bed, 4x4 Dually Cummins/AISIN

    Mountains of Pennsylvania

  4. #4
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    Thanks, I did find the vent in the garage, hard to see at first!

  5. #5
    Site Sponsor Cannon07's Avatar
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    Same here I have half of our bedroom vent covered up.
    2021 351MR
    2017 Jayco 377rlbh (sold)

  6. #6
    Long Hauler offtohavasu's Avatar
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    Couple of things that worked well for us:

    When using the heat pump, keep the fans on the other a/c units in the on/low position. The helped distribute the air throughout the duct work better.

    The eater, as other said the damp works well on the bedroom. In our personal experience, keeping the door closed (after adding the damper) helps with the temps. Heat rises, and the bedroom is one of the highest points, so it naturally made the bedroom warmer with the door open.
    Curtis, Christine, Cole, and Charlotte

    2007 Chevrolet Silverado Duramax LBZ, CCLB
    2020 Momentum 351M

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