Forum Discussion

eb145's avatar
eb145
Explorer II
Apr 24, 2017

getting to zero degrees F in RV fridge.

It is amazing what can happen when you follow the manufacturers written installation instructions.

A couple months ago I spent a few hours and fixed the installation of the RV propane/electric fridge in the slide-out of my 5th wheel. I have the Norcold large 4-door 2118 model. This last week it actually reached zero degrees F in the freezer and was getting the refrigerated section down to near 32 degrees F on setting "7"... I had to reduce to "5".

My wife thought the fridge "wasn't working" because the fan wasn't blowing. The fan inside the fridge used to never stop running because the fridge never stopped running. Until I fixed the "chimney" in back, the fridge could never get cold enough. It just ran constantly.

I used to be able to get to 38 deg.F in the fridge section and 12 deg.F in the freezer section if it was not too hot outside and the sun didn't shine on the fridge.



The problems with the installation were all from the trailer manufacturer not following the installation instructions for the back side of the fridge. The back side is essentially a chimney that lets air move from the outdoor bottom air vent, across the coils and out the top vent. The clearances between the fridge and the "chimney walls" were wrong everywhere in the back of the fridge which let the air move all over the place but not where it needed to go (across the coils). I corrected them and what a difference.

Anyway I am happy now. DW is happy. My food is colder and the ice cream is finally hard.

It was a pain to work on the chimney from the outside through the two vent holes. But the effort was worth it for me.

Maybe Norcold should provide chimney kits to make their fridges work better for more of their customers. They must be losing a lot of their business to residential fridges because the RV manufacturers don't install them correctly.

Happy Camping
Ed
Seeking Advice
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Apr 25, 2017
    Standard clearances for good installations

    Side walls........0" (zero)
    Top ..............0" (zero)
    Back wall ........1" MAX

    No dead air spaces, no gaps, fridge should have a tight fit into cabinet area.
    Air flow should go up thru absorber tubes (large slanted tubes) and then go across condenser fins before being vented out of compartment.

    Lower Vent/Roof Vent allow for Natural Draft (Chimney affect)
    Lower Vent/Top side Vent disrupt draft so fans are required to aid in air flow.
    Fans should be just above absorber tubing pulling air in lower vent and then blowing it up/across condenser fins and then out.

    Baffles should be used if back wall clearances are too wide. Below absorber tubing and above condenser fins (direct/curved/slant as needed)

    Standard Guidelines from Norcold-----works for Dometic too

  • pnichols's avatar
    pnichols
    Explorer II
    Apr 25, 2017
    tinstartrvlr wrote:
    I don't think that will fix the root problem; however, which is pretty much no cooling at all when outdoor temps drop below 40; minimal cooling below 60,


    I wonder if that situation could be helped by installing one or two of the super quiet DC powered computer/electronic equipment fans in the refrigerator's rear ducting to increase the air flow?
  • tinstartrvlr's avatar
    tinstartrvlr
    Explorer
    Apr 25, 2017
    I have many of the same issues, although fridge is in a slide. Distance to back wall is ok; one side is 2" away from wall, other side is 1.25" away from wall, top is almost 3 inches from ceiling. There is some insulation stuck in the gaps but it does little as far as filling the gaps. There was wallboard covering about 2/3 of the fin area. Mfg said it has to be there; Dometic said no way and that I should open the fins up. I went with Dometic's recommendation, although it didn't help as air from the fans just drifts around behind the fridge. I think I am going to create a chimmney out of ductwork metal to pretty much ensure air goes through the fins like it should. I don't think that will fix the root problem; however, which is pretty much no cooling at all when outdoor temps drop below 40; minimal cooling below 60, and super cooling when outdoor temps are high. But one can hope...
  • ScottG's avatar
    ScottG
    Nomad
    Apr 25, 2017
    Based on what I've read here and found with my own TT's, I think the biggest issues you may find are:

    Distance from coils of fridge to back wall incorrect.

    No slope to roof vent. Just a flat ceiling with a hole in it - air doesn't move efficiently through vent. Instructions tell you this should be sloped to direct air movement up through vent. You can use sheet metal to form a chimney.

    Roof vent partially blocked by rubber membrane material. Mine was appx. 60% blocked. They cut an "X" in the material over the vent hole and staple the sides. This left a lot of rubber sticking out into the opening.
  • NHIrish's avatar
    NHIrish
    Explorer
    Apr 25, 2017
    tinstartrvlr wrote:
    Is it possible to post any pics of exactly what you did? I am about to fix the install problem in my rig and seeing what you did might provide some guidance. Install is only part of the problem but it's a start.


    Ditto....or at least what were the major issues that you found.
  • tinstartrvlr's avatar
    tinstartrvlr
    Explorer
    Apr 25, 2017
    Is it possible to post any pics of exactly what you did? I am about to fix the install problem in my rig and seeing what you did might provide some guidance. Install is only part of the problem but it's a start.
  • ScottG's avatar
    ScottG
    Nomad
    Apr 25, 2017
    I did that as a winter project one year. Like you I found all kinds of problems with the install.
    Now, even when it's 104 outside it still cools just fine on electric.
  • 1320Fastback's avatar
    1320Fastback
    Explorer
    Apr 25, 2017
    Guess mine is good to go then. The fridge will put a slim layer of ice on the top of a bowl of water after a day of running before we stock it.
  • Sandia_Man's avatar
    Sandia_Man
    Explorer II
    Apr 25, 2017
    I believe many that have had issues with their RV fridges have experienced poor installation from the factory. Our Dometic is not in a slide and has provided excellent service that rivals what a compressor based fridge can do under similar circumstances. All I did was wire in a dual internal fan from Ebay to help with recovery time from frequent door openings, otherwise it performs admirably whether outdoor temps are in the single digits or triple digits. These newer, large 4 door models with ice makers are on our must have lists in our next rig.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Apr 25, 2017
    YEP ED......

    Majority of RV absorption fridge cooling issues are a direct result if RV MFGs lack of FOLLOWING INSTRUCTIONS

    BOTH Dometic & Norcold have Installation Instructions for each Model of fridge showing cabinet size and clearances to obtain proper DRAFT

    It's not difficult just a bit of TIME which RV MFGs do NOT pay for....piece mil work/slab them in and move to next one.

    I'm surprised that they even cool at all with some of the idiotic installations being done.

About RV Tips & Tricks

Looking for advice before your next adventure? Look no further.25,111 PostsLatest Activity: Feb 18, 2025