RV refrigerators are a different animal from the one in your kitchen. Most Dometic and Norcold units are absorption fridges. There’s no compressor, no hum, no fan you can hear. Instead, a heat source boils an ammonia-water solution, and gravity plus chemistry pull the heat out of the cabinet. That design is quiet and runs on propane, which is great for boondocking. It also fails in ways that confuse people used to standard fridges.
About 24,000 people a month in the US look for help with these units, and almost nobody writes about them honestly. Here’s the real picture.
How an absorption fridge actually cools
The heat source can be a propane burner, a 120V AC element, or a 12V DC element, depending on the model and mode. That heat drives the cycle. Because the cooling depends on liquid flowing by gravity, two things matter more than on any other appliance: the rig has to be reasonably level, and the airflow behind the fridge has to be clear. Get either wrong and cooling drops even when nothing is broken.
Common causes of “not cooling”
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Not level. Park off-level for hours and the fluid pools. Cooling fades. Run it tilted long enough and you can ruin the cooling unit. Level the rig first, every time.
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Blocked ventilation. These fridges dump heat through a lower sidewall vent and a roof vent. Wasp nests, dust, and stored gear behind the unit trap heat. Clear the back, the coils, and both vents.
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Weak or dirty propane burner. On gas mode, a clogged orifice or a flue full of soot starves the flame. You’ll see a yellow, lazy flame or one that won’t stay lit. Cleaning the burner assembly fixes a large share of gas-only no-cool calls.
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Heating element failure on electric. If it cools on gas but not on 120V, the AC element or its connection is suspect. Test the element resistance and check the wiring.
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Control board or thermistor. Norcold and Dometic both use control boards that fail with age and heat cycling. A drifting thermistor tells the board the box is cold when it isn’t, so the heat never kicks on. Both are repairable parts.
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Leaked cooling unit. A yellow ammonia stain and a sharp smell behind the fridge means the sealed unit is done. This one is not a repair. It’s a cooling-unit or whole-fridge replacement.
Troubleshooting you can do safely
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Level the rig and give it a few hours to recover before you decide anything is wrong.
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Pull the lower outside vent panel. Clear nests, dust, and debris. Confirm air can move from the bottom vent up past the coils to the roof.
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On gas mode, watch the flame if you can reach it. A steady blue flame is good. Yellow, flickering, or no light points at the burner, orifice, or propane supply.
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Compare modes. Cold on electric but not gas means a gas-side problem. Cold on gas but not electric means an element or wiring problem. Dead on both, with a clean vent and a level rig, points at the board, the thermistor, or the cooling unit.
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Look and smell behind the unit. Any ammonia residue or odor means stop and call.
When to call a pro
Burner cleaning, orifice replacement, element testing, and board or thermistor swaps are tech work. So is any propane diagnosis. If you smell propane, shut off the supply and ventilate before anything else. And if there’s an ammonia leak, the cooling unit decision needs a real diagnosis so you don’t pay for a part that won’t fix the problem.
We service Dometic and Norcold absorption fridges across the Tri-Valley and listed cities. The $75 diagnostic is credited to the repair, and you get a written estimate before any work beyond the diagnosis. For standard household units, see our refrigerator repair guide and the refrigeration repair service page.
Call (925) 999-4095 or email [email protected] to book. Family-owned, founded 2021. CSLB #1136642, BEAR #50788, BBB A+ rated.
FAQ
Why does my fridge work on shore power but not on propane? That’s a gas-side issue: a dirty orifice, a weak flame, a clogged flue, or low propane pressure. The cooling unit is fine since it cools on electric.
Is a leaked cooling unit worth fixing? You can’t repair a leaked cooling unit, but you can replace the cooling unit or the whole fridge. A diagnosis confirms the leak before you spend on the part.
How long do RV absorption fridges last? Cared for and kept level, a cooling unit often runs 10 to 18 years. Heat abuse from running off-level or with blocked vents shortens that fast.