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How Does an RV Refrigerator Work?

When issues arise, many RVers naturally ask, “How does an RV refrigerator work?” Understanding how RV refrigerators work can help you use yours properly, avoid issues, and increase the lifespan of this essential RV appliance. So, let’s discuss the basic operation of the most popular RV fridges and address the most common questions about RV refrigerators.

How Do RV Refrigerators Work?

RV refrigerator with door open
Photo by Camping World

Like your fridge at home, RV refrigerators store perishable foods. The different RV refrigerator types all work basically the same. A refrigerant picks the heat out of the interior air through heat absorption and releases it to the exterior using the properties of evaporation and condensation.  

However, there are a few differences between the three main types of RV refrigerators: absorption, compressor, and residential. 

Absorption RV refrigerators operate on propane or electricity. This fridge type can be further divided into two-way or three-way designs. Two-way absorption refrigerators run on propane or 120V AC power. Three-way absorption refrigerators run on propane, 120V AC power, or 12V DC power. 

Compressor-driven RV refrigerators require either AC or DC power. The most common type for RV use is the 12-volt refrigerator, which runs on power from your RV’s battery bank. Because they don’t operate on propane, they require adequate battery power or a shore power connection to run for the duration of your camping trip.

Many RV manufacturers will also advertise residential-style refrigerators, which are typically also compression-driven. The difference with residential units is that they generally only run on AC power, meaning you’ll need to be plugged into shore power or a compatible generator. These RV refrigerators are typically found in luxury RVs or destination trailers meant for full-time living.

How Do RV Propane Refrigerators Work?

Propane RV refrigerators use the principles of absorption refrigeration to cool their interiors. When you select the Propane setting on an RV refrigerator, an electrical signal opens the gas valve and subsequently, sparks the igniter. Within 5-10 seconds the flame should ignite to heat the boiler assembly and circulate the refrigerant convective flow, as opposed to using a compressor.

The initial opening of the gas valve requires a minimum battery voltage of 10.5 volts DC in most systems. Verifying adequate battery power and LP supply are two of the simplest troubleshooting tasks to complete if your refrigerator isn’t igniting when set to Propane.  Learn more about how to do so in our guide to using a digital multimeter for RV troubleshooting.

How Do 12V RV Refrigerators Work?

Twelve-volt RV refrigerators use compression-driven refrigeration to cool their interiors. These are the basic steps in a properly functioning refrigerator: 

  1. Gas is compressed and loses heat as it liquefies. 
  2. Pressure on the liquid reduces as it enters the evaporator and the liquid returns to a vapor state (minus the heat lost). 
  3. The absence of heat cools the evaporator, causing its refrigerant to absorb heat from the unit’s interior. 
  4. That heat is carried to the compressor, which forces it into the condenser. 
  5. The condenser releases heat to the outside air, thereby cooling the unit’s interior. 

Because they don’t require an open flame, many consider 12V RV refrigerators to be safer than their absorption counterparts. Their benefits are greatest in off-grid camping applications. 

How Many Amps Does an RV Refrigerator Use?

Technician testing electricity of RV refrigerator
Photo by Camping World

Most absorption refrigerators draw approximately 2.6-2.7 amps in AC mode, while the average 12-volt refrigerator draws roughly 10 amps. Consult your unit’s data plate (or the manufacturer’s specifications) for the most accurate date for the specific make and model. For example, this popular Dometic Americana II Plus RV Refrigerator states that it draws 2.7 amps.

When running an RV refrigerator on AC or DC power, knowing its amp draw can help you calculate how much energy storage capacity (size and number of RV batteries) you need to run it (and other appliances) for the duration of your boondocking trip. 

How To Reset an RV Refrigerator

Control board in Everchill 12V RV refrigerator
Photo by Camping World

The process for resetting your RV refrigerator varies by manufacturer. Some models may require disconnecting power (AC and DC) for 10 minutes and restoring power to complete the reset. Others have a reset procedure that utilizes the refrigerator’s internal control board. 

For example, the owner’s manual for the Norcold Polar 7 and 8 Series RV refrigerators recommends using the internal power button to turn the unit off and back on to complete a reset. 

Technician Tip: Because most appliances inside an RV aren’t made by the RV manufacturer, the owner’s manual from the supplier (i.e., Furrion, Dometic, Lippert, etc.) is your best resource for installation procedures, operating instructions, and troubleshooting tips. 

How Do I Know If My RV Refrigerator Is Working?

RV technicians testing refrigerator
Photo by Camping World

There are three basic questions to ask when wondering if your RV fridge is working: 

  • Is it cooling?
  • Do I hear the ignition when selecting to operate on propane?
  • Is the electric element good?

Let’s dig into each of these questions. 

Is it cooling?

The first test is a simple ‘wait-and-see’ approach to determine if your refrigerator (or freezer) is cooling down. You can do this by turning the refrigerator on, waiting at least 1-2 hours, and returning to feel if the interior temperature is cooling. 

For a more accurate measurement, place an analog thermometer in one gallon of water inside the refrigerator. Run the unit at mid-setting for 12-24 hours. After that period, the thermometer should read 40-43℉ or less (4-6℃ or lower).

Do I hear the ignition when selecting to operate on propane?

The second test confirms that a propane refrigerator is properly igniting on this setting. With a propane RV refrigerator, select the Propane setting. Within 5-10 seconds, you should hear the propane burner igniting. In some cases, you may need to head outside and listen near the refrigerator’s exterior access panel. 

Is the electric element good?

The final test requires a digital multimeter (DMM) and an understanding of the acceptable resistance range for your refrigerator’s electric element, which can be found in the manufacturer’s manual. 

To test the element on your RV refrigerator, disconnect the unit from 120V AC power and disconnect the heating element from the control board. Set your DMM to resistance and place the probes on the heating element’s leads to measure the ohm reading. This should fall within 10% of the manufacturer’s recommended resistance measurement. If your reading falls outside that range, contact an RV service specialist

FAQs About How RV Refrigerators Work

RV refrigerator in Keystone fifth wheel with door open
Photo by Camping World

These commonly asked questions will help you deepen your understanding of RV refrigerators:

How long does it take for an RV refrigerator to get cold?

You should ideally allow an absorption refrigerator to cool for 24-48 hours before use. Compressor refrigerators generally have a shorter initial cool-down period, but your owner’s manual is your best resource for how long it should run before packing your perishable foods.

How much propane does an RV refrigerator use?

Propane RV refrigerators have a BTU rating that indicates their heating rate on the propane setting. A BTU is a unit of measurement (British Thermal Unit). For practical purposes, the rating indicates a refrigerator’s cooling capacity. A higher rating indicates a more “powerful” unit but also means a higher rate of propane consumption. 

Technician Tip: Your refrigerator’s BTU rating can be found on the unit’s data plate, which is often found on one of the interior walls. Information from your refrigerator’s data plate will be useful to technicians when performing diagnostics, accessing the owner’s manual, and ordering replacement parts.

Can I run my RV refrigerator on propane while driving?

It is NOT recommended to run an RV refrigerator on propane while driving. Propane should be shut off at the container valves before towing or driving. 

The reason is safety. In the event of an accident, flammable LP gas will be contained in the DOT cylinders on your towable or ASME tank on your motorhome (minus any residual gas in the propane lines). This minimizes the risk of LP gas adding fuel to a fire. Most propane appliances use direct spark ignition (DSI). The appliance must be turned completely off so that it doesn’t attempt to ignite while driving or refueling, which could cause a very unfortunate thermal event. 

Are you curious about how other RV systems work? Here are a few more helpful resources:

What questions do you have about how RV refrigerators work and how to use them? Let us know in the comments below.

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