Dometic RV Fridge Not Working on Propane
The fridge is warm and you are on LP. Move perishable food to a cooler if the box is warm, then work these checks in order. Most propane failures are an empty tank, a closed rear shutoff, air in the lines after storage or a refill, a CHECK lockout after a failed ignition, or missing 12-volt power so the igniter never fires.
This is for Dometic absorption refrigerators (RM, DM, DMA, NDR, 8-Series). Compressor boxes such as CFX differ.
First, name the symptom
- The display is dark. The fridge will not start on gas or electric.
- The display is on. Electric cools. Gas does not. CHECK is on or flashing, or the panel shows LP. Classic gas-side failure.
- AUTO is on electric while you wanted gas. AUTO is doing its job.
- Warm on gas and electric, or you smell ammonia. Stop. Do not keep restarting.
Dometic’s later operating manuals treat a fridge that has stopped cooling, or that smells of ammonia, as a shut-it-off-now problem. Turn the unit off at the panel. If you smell ammonia, do not open the fridge doors; air out the coach, evacuate, shut the manual LP valve at the rear, and unplug 120-volt power at the back. Call a Dometic dealer. Do not leave a failed unit running, and do not solve it by repeated restarts.
Dark display: 12-volt power to the controls
Most likely cause: The electronic control has no usable 12-volt DC, so it cannot run the display or the gas igniter.
Two-way Dometic fridges (120-volt AC plus LP) do not cool on 12 volts. They still need 12 volts for the board, display, and gas ignition. Dometic’s RM2652/RM2852, DM/DMA, and AMES/AES/Royale/Elite service tips state the refrigerator will work down to 9.6 volts DC.
Fix: Confirm the house battery is not dead. Reset or replace the 12-volt fuse or breaker that feeds the refrigerator, same rating. At the exterior vent, confirm the DC wires are on the terminal block with correct polarity; Dometic tells installers not to use the chassis as a return. Turn the fridge OFF, wait five seconds, then ON. If the panel stays dark after 12 volts is restored, the power or display module is a dealer job.
Display on, will not run on gas
Most likely cause: The burner did not light. Dometic GAS mode tries to ignite for about 45 seconds. If the flame fails, RM and older two-way panels light a CHECK lamp and drop the GAS lamp. On DM/DMA, CHECK flashes and a buzzer beeps. RM1350 flashes LP. RUA 8-Series locks gas after three failed attempts.
Dometic’s DM/DMA line for “Refrigerator does not work in gas operation mode” is: check or change the LP tank, then purge air by repeating ignition. RM2652/RM2852, RM1350, and AMES/AES/Royale/Elite service tips say the same.
Fix:
- Confirm LP is real. Other LP appliances should light. Change an empty tank. Open the tank valve and every manual shutoff, including the one at the rear of the refrigerator. Dometic start-up says not to forget that rear valve.
- Select GAS, not AUTO. In AUTO, AC has priority over gas. If 120 volts is present, the board stays on electric. To force propane, turn AUTO off so the panel is in GAS mode.
- Watch one ignition cycle. You should hear the igniter. Within about 45 seconds the burner should light. If CHECK or LP comes on, the attempt failed.
- Restart to clear CHECK and purge air. Press ON/OFF to OFF, then ON. DM/DMA: OFF five seconds, then ON. The board tries a new 45-second ignition. After storage or an LP refill, air in the lines is normal. Dometic says purging may take three or four restarts.
- Stop after several tries. RM2652/RM2852: do not continue to reset GAS if CHECK stays after three or four tries. Royale, Elite, AMES/AES, and DM/DMA: if several attempts fail, confirm tank and shutoffs, then OFF and a service center.
CHECK does not clear just because AC appears. RM2652/RM2852 and DM/DMA: the fridge will take 120-volt AC, but CHECK stays until ON/OFF is pressed to OFF, then ON.
AUTO is on electric while you wanted gas
Most likely cause: AUTO is working. Dometic AUTO (and AES) selects 120-volt AC first, then (on three-way) 12-volt DC, then LP gas. When AC returns, it switches back to AC regardless of GAS status.
Fix: Turn AUTO off and select GAS. Confirm the rear shutoff is ON. If CHECK is already lit, restart first; AUTO will not clear it. Parked on batteries, use GAS — DC heat on a three-way is for when the engine is running.
CHECK after a fill-up, storage, or a stop at the pump
Most likely cause: Air in the LP lines, or a temporary gas lockout.
After a tank swap or a long sit, Dometic says purge by repeating ignition.
RM1350 AUTO locks gas for 15 minutes when the engine is switched off (LP flashes slowly). RUA 8-Series tank-stop does the same after ignition is switched off. Wait, or pick another energy source. Parked at a pump with AUTO off (manual GAS), Dometic says shut off all LP appliances vented to the outside.
Altitude is separate. DM/DMA: on LP, reduced cooling and burner outage may occur above 5,500 feet; use electric. RUA 8-Series: ignition problems may occur above 1,000 m; switch energy source.
Warm on both propane and electric
Most likely cause: Level, vents, frost, packing, or the cooling unit. The gas flame and the AC heater both drive the same absorption cooling unit. If neither source cools, the burner is not first.
Level the coach so it is comfortable to live in. Dometic: parked unlevel for hours, liquid ammonia can pool in the evaporator and block circulation. Clear the lower sidewall vent and the roof vent (Dometic lists bird or insect nests and spider webs as obstructions). Do not overpack. Defrost buried ice (no knives, no heat guns). Still warm after several hours on a known-good heat source, or ammonia — shut down.
If gas lights and the box stays warm while electric cools, Dometic service literature points at orifice, flue baffle, flue tube, and burner location — technician work. Service tips clean the orifice with an alcohol-based solvent and air-dry; that is not a campsite job. LP pressure is a dealer check: RM2652/RM2852 and AMES/AES/Royale/Elite specify 11 inches of water column at the test port. Odor from fumes: DM/DMA and RM1350 say turn the fridge off and call a dealer.
Error codes
Codes differ by family. Read the data label inside the fridge, then match the table. After a repair, reset with OFF, then ON. RUA 8-Series ERROR-type faults need a 2-to-4-second press of the control knob.
| Family | Code | What Dometic says | Campsite next step |
|---|---|---|---|
| RM / two-way | CHECK | Burner failed to ignite in about 45 seconds | OFF then ON. Purge air up to three or four times. Then tank and rear valve. |
| DM / DMA | CHECK (flash + buzzer) | Burner failed to ignite | OFF five seconds, then ON. Same tank and purge checks. |
| RM1350 | LP (flashing) | Gas ignition failed after 45 seconds; empty bottle, clogged jet, or air in the line | OFF then ON to retry. Change the bottle if empty. |
| RM1350 / Elite | E1 | Disconnected gas valve or gas-system hardware fault | Electric may still run. Use AC until a tech checks gas. |
| RUA 8-Series | 07 | No cooling capacity in gas mode | Level the coach. Reset the error. If it returns — dealer. |
| RUA 8-Series | 50 | Gas lock after 3 ignition attempts | Exchange an empty cylinder. Reset (knob 2–4 seconds). |
| RUA 8-Series | 12 / 51 / 52 / 53 | Gas valve test error, gas lock, valve short, or ignition-electrode short; gas locked | Reset once. If it returns — dealer. Do not keep forcing gas. |
RUA 8-Series gas ignition is three attempts, 30 seconds each, two minutes apart. If all three fail, error 50 locks gas. These RUA manuals are for 230-volt coaches; gas lockout codes still apply.
Call a Dometic dealer, or Dometic at 1-800-544-4881, if the tank, rear valve, and 12-volt supply are good and CHECK or LP still returns; if E3 or ammonia appears; or if the burner area smells of fumes. Pull model and serial off the interior data label first.
Sources
- Dometic, DM & DMA Refrigerators Operating Manual, Form 3317001.000 Rev. B (2021), https://media.dometic.com/externalassets/dometic-americana-ii-dm2682_9600007201_81829.pdf
- Dometic, RM2652 & RM2852 Installation & Operating Instructions, Form 3106406.006, https://bryantrv.com/docs2/docs/operating/2652operation.pdf
- Dometic, RM1350 Installation and Operating Instructions, https://manuals.heartlandowners.org/Appliances/Refrigerator/Dometic/RM1350_Dometic_Refer_Install_&_Operating_Instructions.pdf
- Dometic, RUA5208X, RUA6408X, RUA8408X Operating Manual, https://media.dometic.com/externalassets/rua8408x_9600003697_111452.pdf
- Dometic, Service Tips: AMES/AES/Royale/Elite Refrigerators, Form 3309479.008 (2004), https://documents.cdn.ifixit.com/gfDmbbeDLL1wgwpB.pdf
- Dometic manuals: https://www.dometic.com/en-us/lp/documents-database