5 Common Dometic Fridge Failures and How to Quickly Fix Them
Dometic 3-way refrigerators are extremely popular appliances in RVs and camper vans thanks to their versatility and reliability. However, like any complex system, refrigerator failures can still occur due to a variety of issues.
Common Issue #1 - Faulty or Failed Thermistor
One of the most common causes of temperature regulation issues in Dometic refrigerators is a faulty or failed thermistor. But what exactly is a thermistor and what does it do?
What is a Thermistor and What Does it Do?
A thermistor is a temperature sensor that monitors and regulates the interior temperature of the refrigerator. It's an NTC (negative temperature coefficient) thermistor, meaning its resistance decreases as temperature rises and increases as temperature falls.
The thermistor communicates with the main control board to activate the compressor and fans when cooling is needed. It's a critical component for maintaining the set interior temperature.
Signs of a Faulty Thermistor
Here are some of the most common indicators that the thermistor in your Dometic fridge may be malfunctioning:
- Frequent on/off cycling of the compressor
- Failure to maintain set interior temperature
- Large, erratic temperature fluctuations inside fridge
- Continuously running compressor despite achieving temperature
- Compressor not activating when fridge gets too warm
If you notice any of these thermistor-related issues, it's likely time to test and potentially replace the component.
How to Test and Replace the Thermistor
Diagnosing a faulty thermistor is straightforward with a digital multimeter. Simply set the multimeter to test resistance and probe the thermistor connections while the fridge is running. A stable reading within the acceptable resistance range indicates a functioning thermistor. Erratic readings or readings outside the specified range confirm the thermistor is defective and should be replaced. Consult your fridge manual for the correct resistance range.
Replacing the thermistor involves locating it within the refrigerator machinery compartment, detaching the wiring harness or terminal connectors, removing any securing screws or brackets, then installing the new thermistor and sealing all connections. Be sure to match wire colors when connecting the new thermistor.
Common Issue #2 - Refrigerator Not Cooling on LP Gas
Another frequent complaint with Dometic 3-way refrigerators is failure to cool properly while running in LP gas mode. There are several potential causes behind this issue:
Potential Causes of Gas Cooling Failure
- Obstructed or damaged LP gas lines
- Inadequate gas pressure to the burner
- Blocked burner jets or orifices
- Broken igniter preventing burner flame
- Faulty burner or improperly adjusted burner
Step-By-Step Diagnosis and Repair
Methodically inspecting the various gas-related components will reveal the root cause:
- Check all LP gas valves are fully opened.
- Verify LP gas line is intact and properly connected.
- Use a manometer to test gas pressure at the burner - 10" to 11" WC is ideal.
- Remove and inspect burner assembly - clean any blocked jets as needed.
- Check igniter is operational and producing spark.
- Replace igniter if faulty.
- Adjust burner position/airflow if flame is abnormal.
In many cases, the issue comes down to a bad igniter that simply needs replacing in order to restore full LP gas cooling functionality.
Common Issue #3 - Persistent Noise From Compressor
Hearing annoying new noises emanating from the refrigerator is never a good sign. Let's discuss some potential sources of refrigerator compressor noise and how to resolve it.
What's Causing the Noise?
Common causes of a noisy refrigerator compressor include:
- Worn out compressor bearings
- Internal debris within refrigerant system
- Compressor about to fail
- Loose tubing or components
Excess noise indicates there is a mechanical issue within the compressor itself or the refrigerant flow system that needs addressing.
Resolving Compressor Noise Issues
To properly diagnose the noise source:
- Locate the compressor within the machinery compartment
- Check that tubing is secure with no vibrations
- Test amperage draw and resistance on compressor
- Take note of noise patterns - cyclical, constant, etc.
- Replace compressor if readings are abnormal or noise persists.
While temporary stop-leak products may quiet a noisy compressor, a replacement compressor is the only reliable long-term solution.
Common Issue #4 - Blown Fuse Shutting Off Fridge
Having your refrigerator suddenly shut off due to a blown fuse can certainly be an inconvenience during a trip. Here's a look at why it happens and how to safely get back up and running.
Why Do RV Refrigerator Fuses Blow?
There are a few common reasons the fuse for your Dometic fridge may blow:
- Power surges
- Weak or faulty wiring
- Overloaded circuit
- Damaged internal fridge component
Any of these can trigger the fuse to blow as a protective measure.
Fixing a Blown Fuse
Getting back up and running is straightforward:
- Locate fuse box and identify fridge fuse
- Remove blown fuse and replace with correct amperage
- Restart refrigerator
- If fuse blows again, disconnect fridge to isolate issue
- Check wiring for damage, overloads, etc.
- Address any electrical issues before reconnecting fridge
While merely replacing the fuse may work temporarily, it's important to address any underlying electrical faults to prevent continued blown fuses.
Common Issue #5 - Damaged or Poor Door Seal
leaky door seals can have a surprisingly large impact on refrigerator performance and efficiency. Here's a closer look at the problems it causes and how to fix it.
Impacts of a Leaking Door Seal
Issues caused by defective door seals include:
- Loss of cooling efficiency
- Frost buildup inside cabinet
- Higher electricity usage
- Reduced reliability
- Spoilage or freezing of contents
It's crucial to address seal issues promptly before permanent damage occurs.
Steps to Replace Door Seal
With the fresh, leak-free seal in place, your refrigerator can get back to peak efficiency.
While Dometic refrigerators are generally quite reliable, failures can happen. The good news is that common issues like thermistor or igniter failures, noisy compressors, blown fuses, and leaky door seals can all be addressed with straightforward diagnostics and repairs.
Knowing what to look for and having the proper tools on hand will allow you to get your refrigerator back up and running quickly. With basic mechanical skills, you can handle many repairs yourself without the delay and cost of professional service.
We hope this overview gives you the troubleshooting confidence to keep your Dometic refrigerator performing its vital duties reliably for years of comfortable RV trips ahead.