Start with the thermostat and power source

A Dometic refrigerator that stops cooling usually has a straightforward fix: check whether the thermostat dial is actually turned on, and whether the fridge is receiving power. Many owners discover the thermostat was accidentally bumped to the off position, or the dial is set so low that the compressor never kicks in. Turn the dial to a middle setting — usually marked 1 through 5 — and wait 30 minutes to see if cooling resumes.

Next, confirm the fridge has power. If you're running on 12-volt DC power (from your RV battery), check that the battery itself is charged and that the breaker for the refrigerator circuit hasn't tripped. If you're plugged into shore power or running a generator, make sure the outlet is live by plugging in a lamp or phone charger. A dead outlet will prevent the fridge from cooling even if everything else is working.

If the thermostat is on and power is reaching the fridge, move to the next step. Many cooling problems happen after the fridge has been sitting unused or after travel, so don't assume something is broken yet.

Key Takeaways

  • Check the thermostat dial first — it may be turned off or set too low, which prevents the compressor from running.
  • Verify the refrigerator has power by testing the outlet with another device, and check that the battery or breaker is functioning.
  • Allow 30 minutes after turning on the thermostat before concluding the fridge is not cooling, since the compressor takes time to bring the interior temperature down.
  • Dometic fridges use either absorption cooling (on propane or electric) or compressor cooling, and the repair path depends on which type you have.
  • If the fridge is level and the cooling coils are clear of ice or debris, the issue is usually a failed absorption unit or compressor that requires replacement.

Determine whether your fridge uses propane or electric cooling

Dometic makes two main types of RV refrigerators: absorption models that run on propane or 120-volt AC power, and compressor models that run on 12-volt DC power from your battery. The type matters because they fail in different ways and require different troubleshooting steps.

Look at the back of your fridge. If you see a propane line running to it, you have an absorption fridge. If you see only electrical connections and no propane line, you have a compressor fridge. You can also check your RV manual or the fridge's model number — Dometic absorption models often have numbers like RM or RMD, while compressor models are often labeled CF or CR.

Absorption fridges cool by circulating ammonia through tubes, and they work best when the RV is level. Compressor fridges work like a kitchen refrigerator and cool by compressing refrigerant. Knowing which one you have will help you understand what to check next.

Check that your RV is level if you have an absorption fridge

Absorption refrigerators stop cooling when the RV is tilted more than a few degrees in any direction. The ammonia solution inside needs gravity to flow properly through the cooling tubes, and even a slight lean can interrupt this flow. If your RV is parked on uneven ground, use a level tool to check the tilt, and adjust your leveling jacks or blocks until the RV is as close to level as possible.

After leveling, wait at least one hour before checking whether cooling has returned. The ammonia solution needs time to resettle and resume circulation. If the fridge still isn't cooling after an hour on level ground, the absorption unit itself may have failed — this usually requires replacement rather than repair.

Look for ice buildup or blocked airflow in the cooling compartment

Both absorption and compressor fridges can stop cooling if ice has built up on the evaporator coils inside the fridge, or if the vents are blocked by food or debris. Open the fridge and look at the cooling fins or coils — they are usually located at the back or top of the interior. If you see a thick layer of frost or ice, the fridge is freezing rather than cooling evenly, which means air isn't circulating properly.

Turn off the fridge and let it sit for several hours or overnight so the ice can melt. Do not use a hair dryer or heat gun, as this can damage the cooling system. Once the ice has melted, clean out any food that may be blocking the vents, and turn the fridge back on. If ice builds up again within a few days, the thermostat may be stuck in a position that's too cold, or the defrost cycle isn't working — both of these usually require a technician to repair.

Also check the exterior vents on the back or side of your RV. If these vents are clogged with dust, leaves, or debris, the cooling coils can't release heat to the outside air, and the fridge will run but not cool. Use a soft brush or compressed air to clear the vents, being careful not to damage the fins.

Test the propane supply if you have an absorption fridge

If your fridge is an absorption model and it's level, the next step is to confirm propane is reaching it. Check your RV's propane tank gauge — if the tank is empty or very low, the fridge won't cool on propane. If the tank has propane, listen for a clicking sound near the fridge when you turn the thermostat on. This clicking is the igniter trying to light the burner. If you hear clicking but no flame, the igniter or burner may be faulty.

You can also try running the fridge on 120-volt AC power instead of propane. If you're plugged into shore power or running a generator, switch the fridge to AC mode using the control panel. If the fridge cools on AC but not on propane, the propane system has failed and needs service. If it won't cool on either power source, the absorption unit itself is likely the problem.

Check the compressor and fan if you have a compressor fridge

Compressor fridges have a small motor that compresses refrigerant, similar to a household refrigerator. If your fridge is a compressor model and it's receiving power but not cooling, listen for a humming or buzzing sound when the thermostat is turned on. If you hear nothing, the compressor may not be running at all. If you hear humming but the fridge still isn't cold, the compressor may be running but the refrigerant has leaked out.

Also check whether the small fan on the back of the fridge is running. This fan pulls air across the condenser coils to release heat. If the fan is blocked or not spinning, the fridge will overheat and stop cooling. Clear any debris around the fan and make sure it spins freely by hand when the power is off. If the fan won't spin or the compressor won't run, the fridge likely needs replacement.

Know when to replace the fridge instead of troubleshooting further

If you've checked the thermostat, power, level, and vents, and the fridge still isn't cooling, the cooling unit itself has probably failed. Absorption units and compressors are sealed systems that cannot be repaired in the field — they must be replaced by a technician or swapped out entirely. Repair costs often run $400 to $800 or more, depending on the model and whether you pay for labor.

Before replacing the fridge, you can contact Dometic customer service with your model number to confirm whether a repair is worth attempting. Some older models may have known issues with specific components, and Dometic may offer a replacement or discount. You can also reach out to RV service centers in your area to get a quote for a replacement unit and labor.

Frequently Asked Questions

How long does it take for a Dometic fridge to cool after you turn it on?

Absorption fridges usually take 30 minutes to an hour to reach full cooling, especially if they were off for a while. Compressor fridges cool faster, often within 15 to 20 minutes. If your fridge hasn't cooled after two hours, the cooling system is likely not working.

Can I run my Dometic fridge while driving?

Yes, but absorption fridges work best when the RV is level. If you're driving on a highway, the fridge will still cool, but it may cool unevenly or slowly. Compressor fridges work fine while driving since they don't depend on gravity. Always make sure the fridge is find and won't tip during turns.

What temperature should I set my Dometic fridge to?

Most Dometic fridges have a dial numbered 1 to 5, with 3 or 4 being the recommended middle setting. Setting it too high (5) can freeze food and block airflow; setting it too low (1) may not cool enough. Start at 3 and adjust up or down based on how cold your food gets.

Why is my fridge cooling but making a loud noise?

Absorption fridges make a faint hissing or bubbling sound when running normally. A loud buzzing, clicking, or grinding sound usually means the compressor or fan is struggling. This often happens when the fridge is tilted, the vents are blocked, or the cooling system is failing. Have it inspected by a technician if the noise is new or very loud.

Can I fix a Dometic fridge myself if the cooling unit has failed?

Replacing the absorption unit or compressor requires special tools and knowledge of refrigerant systems. Most RV owners cannot do this safely without training. Contact a certified RV technician or Dometic service center for replacement. Attempting a DIY repair can damage the fridge further or create safety hazards.