Short Direct Intro
The Dometic DM2672 is a robust 6.7 cu ft absorption fridge found in many mid-sized RVs, prized for its ample freezer and reliable three-way operation. However, owners often report frustrating temperature swings—especially in warmer weather or after level shifts. This guide breaks down the specific causes of DM2672 temperature fluctuations and walks you through durable fixes you can apply with basic tools.
Why Does My Dometic DM2672 Cool Intermittently on Gas Mode?
If your DM2672 runs fine on mains (230V) but cycles hot and cold on LP gas, the issue usually lies in the burner assembly or flue baffle. The absorption cycle relies on a steady, clean flame to heat the ammonia solution. A partially blocked jet or a misaligned igniter causes the flame to flutter or extinguish, leading to temperature climbing before the fridge relights. Check the burner orifice (part #960000143) for spider webs or carbon buildup. Clean it with a fine wire or compressed air. Also verify the flue baffle sits squarely: a tilted baffle slants the flame path and reduces heat transfer by up to 40%. Reset the baffle with a small screwdriver if it’s shifted.
Could a Clogged Cooling Unit Cause Wide Temperature Swings in My DM2672?
Yes. The absorption cooling unit (the sealed metal loop behind the fridge) can develop a blockage from burnt ammonia sediment or crystallisation if the unit has overheated. Classic signs: the freezer gets warm while the main compartment stays cold, or vice versa. The fridge might cool for a few hours then suddenly lose all cooling. Unlike a simple thermostat issue, a clogged unit won’t respond to cleaning or level adjustments. Unfortunately, replacing the cooling unit on a DM2672 is a specialist job costing between £500 and £800 (inc. labour) in the UK, often more economical than a new fridge. If your fridge is over 8 years old with these symptoms, budget for a replacement.
How Do I Test the DM2672 Thermostat for Faults?
The DM2672 uses a capillary bulb thermostat (part #960000166). Over time, the bulb’s gas charge can leak, causing it to sense the wrong temperature. To test, set the fridge to its coldest setting and measure the evaporator fin temperature with an infrared thermometer after 4 hours of stable running. Target should be -6°C to -8°C in the freezer, 4°C in the fridge section. If the fin temperature is correct but the interior is warm, the thermostat is stuck closed—replace it. If the fin is too cold (below -12°C) but the fridge fully shuts off early, the capillary charge is weak. Replacement runs about £35–£50 online; installation takes 30 minutes with a screwdriver and a small spanner for the capillary clip.
| Severity Level | Typical DM2672 Symptom | What It Means |
|---|---|---|
| 🟡 Usually Not Urgent | Fridge cools fine in the morning but warms by evening; occasional off-cycle. | Likely ambient temperature shift or low battery voltage. Check vents, 12V supply, or gas pressure. Often fixed by cleaning flue or adjusting RV levelling. |
| 🔴 Needs Attention Soon | Fridge stops cooling completely after several hours of operation; ammonia smell (sharp, pungent). | Cooling unit failure or major blockage. Risk of ammonia leak. Turn off fridge immediately, ventilate area, and consult a certified RV fridge technician. Replacement cooling unit or new fridge needed. |
| 🔴 Needs Attention Soon | Freezer frosts heavy while fridge stays lukewarm; compressor never shuts off. | Thermostat stuck open or capillary tube clipped to evaporator incorrectly. Check clip position first; if correct, replace thermostat. |
Can Poor Ventilation Cause the DM2672 to Cycle On and Off?
Absolutely. The DM2672 rejects waste heat through a roof vent or side louvre. If the airflow path is blocked—by mud dauber nests, leaves, or even a stack of camping gear—the fridge’s condenser can’t shed heat. The safety thermostat will then cycle the burner off to prevent overheating, causing erratic temperatures. Check both lower intake and upper exhaust vents. Ensure at least 6 inches of clear space above the fridge’s top vent. You can buy a DM2672-specific vent cover mesh kit (about £25) to keep debris out.
Does the DM2672 Require Specific Levelling to Avoid Fluctuations?
Yes. Absorption fridges like the DM2672 need the RV level within 3° side-to-side and 6° front-to-back when running on gas or 12V. If the RV tilts too much, the ammonia solution flows unevenly, creating hot spots and temperature swings. A cheap carpenter’s spirit level placed on the freezer floor (not the RV floor) tells you the true angle. Bubble centre = fine. If it’s off, level the RV before starting the fridge. Even a 30-minute uphill parking can upset the cycle for hours.
What Owners Say
“Ours started swinging 10° after a hot week in the South of France—turns out the flue baffle had slid down. Pushed it back up with a screwdriver, rock steady since.” – Graham M., VW Crafter conversion owner
“Spent £200 on a new control board but the real fix was just cleaning the burner jet. Fridge tech showed me. Now I do it every spring.” – Linda P., 2017 Swift Kontiki
“Our DM2672’s thermostat read 4°C when the real temp was 15°C. Replaced the capillary assembly (cheap from Amazon) and it’s been perfect for two years.” – Dave R., Hobby 500 owner
Frequently Asked Questions
- Can I run my Dometic DM2672 while driving on a bumpy road?
Yes, but only on 12V mode. The gas flame can blow out on rough roads, and 230V is only safe when connected to shore power. The fridge’s absorption system handles bumps fine as long as it’s level enough. - Why does my DM2672 freezer frost up heavily even though the fridge section isn’t cold?
That usually means the defrost timer (if your model has one) or the thermostat is faulty. The freezer coil freezes into a block because the fridge never gets a defrost cycle. Check the defrost heater and timer first. - Is it safe to use my DM2672 if I smell ammonia?
No. Turn the fridge off immediately, ventilate the RV, and do not use it. An ammonia smell means a leak in the cooling unit, which can be dangerous. Call a qualified RV fridge technician. - How often should I clean the DM2672 burner?
At least once a year, ideally before a long trip. If you park in dusty or forested areas, clean it every six months. A clean burner ensures a stable gas flame. - Could low 12V voltage cause my DM2672 to fluctuate?
Yes. The control board needs a minimum of 10.5V to operate correctly. A weak battery or long thin cables can drop voltage below that, causing the board to reset or shut off the burner. Check battery voltage at the fridge terminals. - My DM2672 works on gas but not on 230V—what’s wrong?
First, check the mains breaker and any GFCI outlet near the fridge. If those are fine, the 230V heating element (often part #960000141) is the likely culprit. Testing with a multimeter is straightforward; replacement costs about £60.
