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.
Thousands of RV owners a year search 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. A tech will clean or replace the burner assembly — this clears 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 heating element or its wiring is suspect. Testing and replacing that component is electrical work; a tech handles it with the right meters and parts.
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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 once a tech confirms which one is at fault.
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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.
Checks you can do before calling
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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, observe the flame through the access panel. A steady blue flame is good. Yellow, flickering, or no flame points at the burner, orifice, or propane supply. Stop there — don’t start probing the gas line.
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Compare modes. Cools on electric but not gas means a gas-side problem. Cools on gas but not electric means an element or wiring problem. Dead on both, with clean vents and a level rig, means the board, thermistor, or cooling unit needs professional diagnosis.
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Look and smell behind the unit. Any ammonia residue or odor means stop using it, ventilate the space, and call.
When to call us
Once you’ve confirmed the rig is level and the vents are clear, everything else is tech work. Propane system diagnosis requires the right equipment and, in California, a CSLB contractor. Electrical testing with live voltage isn’t a DIY job. Control board and thermistor swaps look simple but getting the diagnosis wrong means buying parts that don’t fix the problem.
The most important thing a proper diagnosis does is tell you whether you actually have a cooling unit failure. The cooling unit is the expensive part. Most “dead” absorption fridges aren’t the cooling unit at all — they’re a dirty burner, a bad board, or a failed element. You need to know which camp you’re in before spending anything significant.
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.