13th Oct 2026
Dometic Americana Not Cooling on Propane (Cools Fine on AC): Troubleshooting Flowchart
WEAK ON GAS ONLY
Dometic Americana Not Cooling on Propane (Cools Fine on AC)
The fridge gets cold on shore power but runs warm on propane. Since AC cools properly, the cooling unit is fine. The flame just isn’t putting enough heat where it needs to go. Check the gas pressure, the burner and jet, and the flue tube and baffle.
Dometic Americana & Americana Plus · RM2351 through RM2862
Fits these models
Different model? These steps are for the models above, from Dometic’s service manual for them. For any other Dometic fridge, ask a tech before you test or order parts.
Before you start
- Safety first. Never use a flame to check for gas leaks. Gas tests should be done by a qualified service technician.
- Where things are. The burner, jet, gas valve and test port are behind the lower outside vent. The flue tube runs straight up from the burner, and the spiral baffle hangs inside it from the top.
- Do this once a year. Dometic says to clean the burner and flue tube at least once a year. Most weak-on-gas problems are carbon and rust buildup.
- You’ll need a manometer, a multimeter that reads millivolts, a flue brush, and an alcohol-based solvent.
PART A · GAS PRESSURE
Is the burner getting enough gas?
STEP 1
Check the gas pressure
Connect a manometer to the test port below the solenoid valve. With the burner lit and about half the RV’s other gas appliances on, it should read 11 inches water column, and never more than 12 with everything else off.
Is it about 11 inches at the test port?
Find where the pressure drops
Measure at the gas line going into the fridge. If it’s low there too, the problem is the RV’s regulator or supply. If it’s 11 inches going in but low at the test port, the solenoid valve isn’t opening all the way. Replace the solenoid valve assembly. For the RM2862, that’s the Gas Valve / Burner / Igniter Assembly 3850730569.
PART B · BURNER & JET
Good pressure. Is the flame clean and in the right place?
STEP 2
Clean and check the burner
Turn the fridge off and let it cool. Remove the burner cover. The burner’s slots should sit directly below the flue tube. Soak the burner in an alcohol-based solvent and let it air dry. Check that it has a good ground, since a poor ground causes erratic gas operation.
Was the burner dirty, out of position or poorly grounded?
Clean, realign and retest
Reinstall it with the slots centered under the flue, then run the fridge on gas for a day.
STEP 3
Check the burner jet
The jet is brass with a laser-drilled ruby in the center. Soak it in an alcohol-based solvent for about an hour and let it air dry. Never push a wire or pin through it, or blow air through it. Check that it’s the right size for your model:
| Model | Jet size |
| RM2351, RM2354 | #39 |
| RM2451, RM2454, RM2551, RM2554 | #43 |
| RM2652, RM2662, RM2663, RM2852, RM2862 | #58 |
Was it dirty or the wrong size?
Clean or replace the jet
Install the correct size, clean, and retest. A jet that’s too big or too small changes the heat and lowers cooling, so never resize it.
PART C · FLUE TUBE & BAFFLE
The flame is right. Is the heat reaching the cooling unit?
STEP 4
Clean the flue tube
Remove the flue cap at the top of the flue (not every unit has one) and pull out the spiral baffle. Run a flue brush (Dometic part 0151404001) down the tube, then clean the burner area of anything that fell.
Was there carbon or rust buildup?
Reinstall and retest
Buildup blocks the heat from reaching the cooling unit. Put the baffle back at the right height (Step 5) and run the fridge on gas for a day.
STEP 5
Check the baffle height
The baffle slows the hot air so the heat lands in the right spot on the cooling unit. Too high or too low and the heat goes to waste. Check it against your model:
| Model | Baffle above burner | Baffle size |
| RM2351, RM2354, RM2451, RM2454, RM2551, RM2554 | 1-15/32″ | 3-15/16 x 25/32″ |
| RM2652, RM2662, RM2663, RM2852, RM2862 | 1-7/8″ | 5-1/8 x 13/16″ |
Is it at the right height?
Adjust the baffle
Set it to the correct height above the burner and retest. Check your model’s parts list for the right baffle.
PART D · FLAME SENSING & BOARD
The heat path is clean. Does the board keep the flame on?
STEP 6
Test the thermocouple
Units with a separate igniter use a thermocouple over the burner. Set your meter to DC millivolts, black lead on J3 (original board) or J4 (current board), red lead on J10 or the other thermocouple lead. Run the fridge on gas.
Is it 25 to 35 millivolts with the flame burning?
Fix the thermocouple
Below 18 millivolts, gas operation gets erratic and the flame may drop out. Low gas pressure, carbon buildup or a thermocouple out of position can all cause it. Center it over the burner so it covers 3 slots, clean it, and replace it if it’s still low. Integrated igniter units don’t have a thermocouple.
Check the lower board
If the burner cuts out and relights, or the CHECK light comes on now and then, the lower board may be dropping the gas valve. Replace it and match the part number on your old board’s label. On rough-riding coaches the flue tube weld can crack, which also causes weak gas cooling. If the board isn’t the problem, ask a tech.
Dometic Hercules Board 3316348.900 →OEM board with built-in reigniter. Replaces 3850712013. 
Dinosaur 3850712.01 Board →Aftermarket replacement for 3850712-xxx boards. 
Dinosaur 3850415.01 Board →Replaces 3850415 boards only.Still stuck? ask a tech with your model, product number and the readings you got. We’ll confirm the part before you order.
Covers the Dometic Americana and Americana Plus: RM2351, RM2354, RM2451, RM2454, RM2551, RM2554, RM2652, RM2662, RM2663, RM2852 and RM2862. Based on the Dometic RM2xxx service manual, Diagnostic Flow Chart, Symptom 7: Insufficient cooling on gas, cools properly on AC mode.