Select Troubleshooting Subject in Menu Above ⇑

Dometic Troubleshooting & Repair Landing Page + VIDEOS

Ever ask – Where do I get started fixing my Dometic RV fridge? This page has a step-by-step troubleshooting logic tree. It covers most all problems that can occur with a Dometic fridge & includes 'How To' videos!


The above menu items list all the repair subjects for each part and system on your Dometic RV fridge that are necessary for how to fix a fridge that is not cooling.


Below on this page are:

Fridge Troubleshooting Step by Step

INSTRUCTIONS: Select the symptom that best suits your situation, click the subject and the logic tree will open with the next question or a solution.

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  • Fridge Cooling Poorly

    • Fridge is on Shore Power
    • YES

      • Switch to LP Gas Mode

        • Fridge cools within 4 hours on LP Gas?
            There is a problem with the Shore Power.
            Make sure you have 120VAC at the fridge receptacle and that the polarity is correct.
            An extension cord can be plugged directly into the fridge plug to eliminate any issues that may be in the RV wiring.
            There is a fuse under the cover of the control box.
            Use following links to check the heaters:


            ☝ Test AC Heater & Specifications


            ☝ Test AC Heater & Specifications

    • Fridge is on LP Gas
    • YES

    • Fridge Cools Poorly on LP Gas & Shore Power
    • YES

      • Disconnect Cabinet Temperature Sensor
          By disconnecting the cabinet temperature sensor (thermistor) it will force the fridge to run 100% of the time. If the fridge does not cool on either heat source, go to Fridge Fails above Tests below in this tree.


          ☝ Test Thermistor


          ☝ Test Thermistor

        • Industry Standards for Cooling
        • ANSI Standards

            Following test requires measuring in a glass of water the fridge temperature.
            The glass of water is to offer thermal mass, but most wireless fridge thermometers will work because they have the mass of the batteries in the sensor.

            TEST: Run fridge with either a functioning thermistor, or disconnect the thermisor and run fridge for 6 to 8 hours. For the following size of fridge, the thermometer should read:

            3 to 6 cubic foot Fridge: 43°F or less at 90°F ambient temperature.

            8 cubic foot Fridge: 43°F or less at 110°F ambient temperature.

            Freezer Compartment: 12°F or less (water not needed for this test).

    • Fridge Fails above Tests
    • YES
        If the fridge is not cooling on either of the heat sources, Shore Power or Propane heat,
        there is the possibility the cooling unit is failing or has failed.
      • Cooling Unit Test
          The cooling unit is completely powered by the boiler,
          thus the boiler temperature tells the diagnostician two things:
          1) The pressure in the cooling unit.
          2) If the fluids are circulating in the cooling unit.

          Do you have a Fridge Defend?
        • YES

        • NO
            Other than viewing yellow powder where the cooling unit cracked and failed,
            or if the boiler is gurgling when heated, there is no way to test the cooling unit boiler.
            ☝ Photo of Failed Boiler

  • Hot Weather Fridge not Cooling

  • Codes: Fault – Error – Diagnostic

  • No Lights on Fridge Control Panel

  • Power Supply Quality Test

      There are two tests, one is for the DC voltage at the fridge controller. The other is for AC voltage on the system.

    • DC Tests

        The standard in the industry:

        Less than 10.5VDC the fridge will not run.

        Greater than 20VDC damage will occur to 12VDC automotive equipment.

      • Do you have a Fridge Defend?
      • YES

    • AC Tests
        Place volt meter in AC mode of operation, measure the fridge 120VAC supply voltage.

        The standard in the industry:

        Less than 6VAC of AC voltage should be on the 12VDC supply line.

        If RV is connected to shore power, disconnect and measure again if greater than 6VAC.

        If AC voltage is acceptable, most likely the RV 120VAV to 14.5VDC battery charger has a problem.

        If AC is not acceptable, most likely the RV 12VDC to 120VAC inverter is putting the AC voltage onto the DC line.

        TIP: Start pulling fuses and disconnecting electrical loads until the problem is found.

  • LP Gas Mode does not Work

      When the control is put into the LP Gas mode:
      • The gas valve will click when it opens.
      • The igniter will strike.
      • Then the flame should light within two strikes of the igniter.

      Thus, it is important to open the burner cover to observe these events.

      For the following, we assume you have turned on a burner on your stove and it lights.
      Thus, you know you have propane fuel in the tank and pressure in the line.

    • Gas Valve
  • Looking Around - First Step

    Norcold Plugged Condenser
    Plugged Norcold Condenser

    This photo shows a plugged condenser; by just looking around many RV fridge problems can be fixed. Because the owner had a Fridge Defend on his Norcold, and the Fridge Defend keep tripping, the owner had to find out why?

    It turns out that it was just this simple; the condenser became plugged with insulation from the RV, the fridge cooled poorly on both shore power and LP Gas (propane).

    Troubleshooting Basics

    In our 48 years of RV refrigerator, automotive electrical, and RV systems troubleshooting, we have come to find that most problems are simple to solve.

    Do it Yourself (DiY) fridge repair is what we promote because you have all the facts, but we are also here to help. All Fridge Defend safety and reliability device owners get consultation for fixing their fridge.

    Just Look Around -- It Can Save Money!

    Complete RV Fridge Repair Video Series

    We give the viewing option for either YouTube (green border) or our webpage (blue border) showing the same video (no ads or pop-ups).

    1 - RV Fridge Essentials

    YouTube Player

         Fridge Defend Player

    VIDEO: This video shows the components on an RV fridge. This is the index for the remainder of the Complete RV Fridge Repair Series. This video shows the back side of the fridge including propane (LP Gas) components such as the Gas Control Valve (SOV), Burner, and Boiler Assembly, along with other cooling unit components such as Electric Heaters. Also, inside the fridge the thermistor and cooling fins are shown.

    2 - Thermistor Temperature Regulation

    YouTube Player

         Fridge Defend Player

    VIDEO: The RV refrigerator has a device called a ‘thermistor’ that regulates the temperature within the RV fridge. This video teaches how to troubleshoot and repair the thermistor RV refrigerator temperature controller.

    TEXT: Norcold Thermistor & Temperature/Ω Values

    TEXT: Dometic Thermistor & Temperature/Ω Values

    3 - Troubleshoot Heat and Boiler

    YouTube Player

         Fridge Defend Player

    VIDEO: This video helps teach how the Dometic and Norcold RV refrigerators are driven by a boiler. The video shows basic instrumentation need to checking the boiler and information about the electric and gas heaters.

    Click for Data Interface Controller for Advanced Diagnostics

    4 - Troubleshoot Electric Heaters and Fuses

    YouTube Player

         Fridge Defend Player

    VIDEO: This video teaches how to troubleshoot and repair RV refrigerator electric heaters and the controller fuses for No AC type errors and trouble codes.

    TEXT: Norcold Electric Heaters

    TEXT: Dometic Electric Heaters

    5 - Troubleshoot LP System Pressure and Filter

    YouTube Player

         Fridge Defend Player

    VIDEO: When the fridge does not cool when in the propane (LP Gas) mode, there may be issues with the LP filter and or the regulator pressure. This video teaches how to troubleshoot and repair these problems.
    VIDEO: Safe Operation of Liquid Propane Gas
    TEXT: Norcold LP System Pressure and Filter
    TEXT: Dometic LP System Pressure and Filter

    6 - Troubleshoot LP Gas Burner, Igniter, Jet, and Flue

    YouTube Player

         Fridge Defend Player

    VIDEO: This video teaches how to troubleshoot and repair the propane (LP Gas) burner and igniter system including the gas jet and flue cleaning procedures.

    TEXT: Norcold Burner & Igniter  &  Norcold 'Popping-Burner' Solution

    TEXT: Dometic Burner & Igniter

    7 - Troubleshoot Gas Valve

    YouTube Player

         Fridge Defend Player

    VIDEO: This video shows how to troubleshoot and repair the RV fridge burner gas valve including ohms and voltage checks.

    8 - Troubleshooting Poor Cooling Performance

    YouTube Player

         Fridge Defend Player

    VIDEO: This RV fridge has a problem that came from the factory, not enough thermal mastic. This video shows how to troubleshoot and repair the fridge for this particular poor or not cooling issue.

    9 - How to Remove Cooling Unit

    YouTube Player

         Fridge Defend Player

    VIDEO: This video shows how to remove the cooling unit from a Dometic or Norcold RV refrigerator.

    10 - How to Properly Apply Cooling Unit Evaporator Thermal Mastic

    YouTube Player

         Fridge Defend Player

    VIDEO: This video shows the critical cooling unit replacement step of properly applying the evaporator thermal mastic.

    11 - How to Properly Install Dometic or Norcold Cooling Unit

    YouTube Player

         Fridge Defend Player

    VIDEO: This video shows how to properly install a Dometic or Norcold cooling unit, including the critical step of sealing the evaporator.

    12 - RV Fridge Fan Facts

    YouTube Player

         Fridge Defend Player

    VIDEO: This video clears up some misconceptions about RV refrigerator ventilator and defrost fans. Fans increase efficiency, but do not prevent the cooling unit boiler from overheating.

    13 - Install Dometic & Norcold Fan Sensor

    This video shows how to install the fan sensor for Dometic and Norcold RV refrigerators.