RV Refrigerator Not Cooling on Propane: Fix Guide
RV absorption refrigerators from Dometic and Norcold run on either 120V electric or propane, and a very common complaint is a fridge that cools fine on electric but poorly or not at all on gas. Because the cooling process is identical in both modes, a propane only failure almost always means one thing: the burner is not delivering enough clean heat. That is fixable, and this guide walks you through it. One safety rule first: any time you smell propane near the fridge compartment, shut off the gas at the tank and stop. Leak diagnosis is professional work.
How an Absorption Fridge Works (30 Second Version)
Absorption fridges have no compressor. A heat source, either an electric element or a propane flame, boils an ammonia solution and drives it through a sealed circuit that produces cooling. Electric mode and gas mode heat the same boiler. So if electric mode cools properly, the sealed system is good, and your propane problem lives in the burner assembly, the gas supply, or the controls.
Confirm the Basics
Verify propane is flowing to the rest of the rig: light a stove burner. If the stove will not light either, your problem is upstream at the tank valve or regulator, not at the fridge. Confirm the fridge is set to gas mode or auto, and give it time. Absorption fridges are slow; a warm fridge needs 8 to 12 hours to pull down to temperature, and testing it empty with a thermometer beats guessing.
The Burner Assembly Is the Usual Suspect
Behind the lower exterior access panel you will find the burner assembly at the base of the flue. Rust flakes fall from the flue into the burner, and spiders love the orifice. A contaminated burner produces a weak, lazy, yellow flame instead of the strong blue flame the boiler needs. With the gas off, remove the burner box cover and clean the burner and the area around it with compressed air and a soft brush. Do not poke anything into the orifice itself; if the orifice is clogged, it should be removed and cleaned in alcohol or replaced. While you are in there, have a look up the flue; a chimney sweep style flue brush knocks down the rust that will otherwise fall right back into your clean burner.
Read the Flame
Relight the fridge on gas and watch the flame through the burner viewport. You want a steady, mostly blue flame that stays lit. A yellow, wavering, or undersized flame means contamination you have not cleared yet or low gas pressure. A flame that lights and then drops out after a few seconds points at the thermocouple or flame sense circuit, which tells the gas valve the flame is alive; these are inexpensive parts that age out. If the igniter clicks endlessly and never lights, check the electrode gap and look for a cracked ceramic insulator, the same failure that plagues water heaters.
The Leveling Rule
Absorption fridges must be reasonably level to cool. The ammonia circuit depends on gravity, and running an absorption fridge significantly off level for hours can cause the boiler to overheat and, over time, permanently damage the cooling unit. If your fridge cools well at some campsites and poorly at others, level is your first suspect. Within a few degrees of level is fine; parking on a noticeable slope overnight is not.
When It Is Not the Burner
If the flame is strong and blue, the rig is level, and the fridge still will not cool on gas even though electric mode works, the control board or gas valve is the next suspect, and that diagnosis takes a meter and the service manual for your model. And if the fridge cools poorly on both electric and gas, with a possible ammonia smell or yellow residue at the rear, the sealed cooling unit itself has failed, which is a replace the cooling unit or replace the fridge decision.
Get Instant Help With Your Fridge
Tell FixMyRV.ai your fridge brand, model, and exactly what the flame is doing, and our diagnostic service, backed by over 50,000 pages of professional repair manuals, will walk you through the sequence for your specific unit, including the model specific fault codes Dometic and Norcold use.