Fridge Defend by ARP Protects your Dometic or Norcold

Fridge Defend by ARP® controls the high temperatures that can lead to fridge failure and safety issues, our fan controller improves efficiency and repairs fan problems without removal of the fridge in most cases for Dometic, Norcold & Amish RV Refrigerators.

The following is a guide that explains the difference between the Fridge Defend versions. Also, the advantages of one version of control over the other.

Table of Contents

Instructions: Subjects are listed on left. Click the link to the right to go directly to the subject matter on this page.

What Does the Fridge Defend by ARP Do?

The Fridge Defend by ARP is a patented automatic temperature monitoring device. Where patented means no other device offers this protection and automatic means that if your Dometic or Norcold cooling unit overheats, the ARP Control senses the "abnormal temperatures" and Defends your fridge by turning off the heater that drives the refrigeration process. The ARP will automatically restart your fridge if an overheat situation arises. Neither the Dometic thermofuse (thermal switch) nor the Norcold high temperature limit switch (recall NHTSA 10E-040) can claim to protect the cooling unit from failure or automatically restart your fridge.

What Will Cause a Dometic or Norcold Cooling Unit to Overheat?

Here is a partial list of reasons that your RV fridge can overheat, neither Dometic nor Norcold controls address any of these issues:

Please click to see video How ARP Protects my Fridge

Why is the Fridge Defend by ARP a Safety and Failure Prevention Device?

The Fridge Defend monitors the cooling unit "normal" boiler temperatures. The cooling unit boiler of your Dometic or Norcold will run at constant normal temperature as long as the cooling unit is preforming in a safe manner (see link above). When the cooling unit boiler temperatures rise above the "normal" temperatures, damage to the cooling unit results. Cooling unit damage can lead to premature cooling failure or even worse, the cooling unit boiler can crack due to excessive thermal stress and cause the fluids to leak externally resulting in an RV fire.

Fridge Defend by ARP Ratings Speak for Themselves

Fridge Defend by ARP Rated
4.8 stars based on 135 customer reviews

What Products are Offered by ARPC LLC?

Product Description: We have two models of controller, the Basic Fridge Defend & Fridge Defend + Fan Control. Both controls protect the cooling unit by monitoring the boiler temperature. The Fridge Defend + Fan Control has an an additional fan controller which improves the fridge efficiency. ARPs products range in price from $147.50 to $225.00

ARP Control Improves Safety, Reliability, and Efficiency


So what is up with these numbers?
Out of the total number of customer ratings, these graphs show how many people that bought an ARP Control felt that their family was safer, their fridge was more reliable, and that the ARP + Fan Control made their fridge more efficient. Please note that none of the pets that were left alone in the RV reported, but an independent survey (the dog next door) stated that 100% of pets insist their master is goofy if they do not purchase an ARP Control for safety.


Our Standard device comes with everything needed to install it yourself - the Controller, Platinum Temperature Probe, wiring, screws and wire connectors (some installs require unique power and ground connectors not included).


This control offers economy and ease of use while fully protecting your fridge from boiler overheating. The v4.0 may be used on all Dometic and Norcold & Amish fridges with roof type venting for the cooling unit with some exceptions, please see purchase page for details. Please see the Norcold and Dometic specific install pages for more information.

Relevant Links

Demonstration ARP Control on Norcold Refrigerator

Why RV Refrigerators Fail

Why is ARP Necessary

#1 v4.0 Basic ARP Control Kit

ARP RV Fridge v2.0 Protection

This control is the same as the v3.01 with the following exceptions:
The v4.0 has diagnostics functions that are not on the v3.01. For example, now the operator can view a startup function test of the control. If any errors occur you will receive a message. Also, the RV fridge troubleshooting keeps getting better by recording power issues and giving the diagnostician the ability to read the fridge voltage from the Fridge Defend screen.


This control offers economy and ease of use while fully protecting your fridge from boiler overheating. It may be used on virtually all Dometic and Norcold fridges roof type venting for the cooling unit. Please see the Norcold and Dometic specific install pages for more information.

Relevant Links

The price for our Standard v4.0 Absorption Refrigerator Controller as pictured is $147.50

#2 v4.1 ARP + Fan Control

ARP RV Fridge Fan Kit

The ARP + Fan Control is the last word in RV fridge control. In addition to the great protection offered by the standard ARP, the Fan Controller has a precision temperature sensor that precisely controls when your fans run.


This item comes without fans so the end user can use their existing fans if they wish. This control can be used on any Dometic or Norcold fridge to improve the efficiency. In our testing we found that using our blower fan with the ARP + Fan Control in a roof vented type cooling unit, the fridge ran about 25% less time in hot weather.

For side-vent or slide-out cooling unit installations this is a must have item. This is because these installations have known cooling air circulation issues. We recommend using one of the controls below that comes with a power blower fan in side-vent or slide-out cooling unit installations. To better understand what a side-vent install is, please click on the RV Fridge Fan link below and look at the second drawing on this page.

Relevant Links

The price for the v4.1 ARP + Fan Control is $177.50

#3 v4.1 ARP Fridge Protection Control with Fan Controller and 1 Fan

ARP RV Fridge Fan Kit RV Fridge Vent

This is the above described ARP + Fan Control with the exception that it is sold with one high volume blower fan. See fan specifications below.


We recommend the #3 package for roof vent applications. One blower mounted properly will work in most applications if economy is desired. The next control (#4) is recommended for side-vent applications to further increase efficiency.

Relevant Links

The price for the v4.1 ARP + Fan Control + High Efficiency Blower Fan is $195.00

#4 v4.1 ARP Fridge Protection Control with Fan Controller and 2 Fans

ARP RV Fridge Fan Kit RV Fridge Vent Upper RV Fridge Vent

This is the above described ARP + Fan Control with the exception that it is sold with 2 high volume blower fans. See fan specifications below.


We recommend the #4 package for roof vent and side-vent applications. Having one fan at the bottom and one at the top vent really moves the air! The second image shows the side-vent type fridge install with a blower mounted on the top vent door. This has the advantage of sucking the hot air out of the top of the cooling unit compartment.

The following image is the lower fan pushing the cool air up so that the upper fan has a boost making it easier to get that hot air away from your RV.

Relevant Links

The price for the v4.1 ARP + Fan Control + 2 High Efficiency Blower Fans is $225.00

#5 Quiet High Performance Blower Fan

RV Fridge Fan RV Fridge Fan Specification

L Blower = Low Noise If your fridge needs help cooling, we had this blower fan built just for your RV. It is a 12 VDC @ 0.3 amp datasheet specification, ball bearing blower with dimensions of 120 x 120 x 32mm. This centrifugal blower moves 25 cubic feet per minute of cool air across your cooling unit. The speed is 1800 RPM and the noise is a quiet 39 decibels. This fan has the best power, noise, and air flow performance for your fridge, see curve 'L' on chart.

The price for each blower fan is $30.00

NOTE: We recommend 2 blowers, one top and the other bottom for side-vent applications. If you have the small bottom vent door like is found on some Winnebago's we recommend 2 blowers, one top in the roof vent and the other bottom on the small vent door.

#6 The Last Word in Fridge Troubleshooting

ARP RV Fridge Diagnostics Tool
Relevant Links

We have very limited availability on our "Data/Interface/Monitoring" Absorption Refrigerator Controller. This particular device is also installed inside the RV. The difference is it has a "Data Port" for computer interface monitoring. A Software interface package for a PC is included with this product.

Data Interface Controller

NOTE: Data Collection devices are not going to be produced for the next production run. Please us the Contact Us in the info menu at bottom of page if you would like to purchase one of these diagnostic devices while supplies last.

The Data/Interface Absorption Refrigerator Controller is available for $199.99

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Introducing the Fridge Defend Series of Control by ARP

If you do not have a v4.x or newer Fridge Defend by ARP, you are missing out on some very cool benefits (pun intended). The v4.1 and newer Fridge Defend controls have the following improvements recommended for all Dometic and Norcold RV fridge. Here is a list of refrigerators that see large improvement with our new controls: Norcold N3150, 1200 & 1210 series, and the 2118 series. Also, improvements are needed on all Dutch Aire (Amish) cooling unit and Dometic side-by-side fridges including the RM1350.

With the introduction 3.01 and the v3.11 controls, all of the factory settings can be restored by the push of a button.

An advanced proportional-integrated-derivative (PID) control scheme has been added. The advantage to this type of control method is temperature tracking which improves control of new style Norcold, older Dometic, and high quality aftermarket cooling units such as Dutch Aire (Amish) and other makes.

The v4.x series of controls introduces a smart startup error checking system, if errors exist, they are reported on the display. In addition, every day the control will check itself again. The daily periodic test is combined with the algorithm that stops the fridge from going into the defrost cycle which improves cooling performance in hot weather. If the user chooses, the periodic test and defrost defeat cycle can be turned off.

Improved fan controller increases fridge cooling efficiency by adding more cooling fans with increased control range, now the fan temperatures are easier to fine tune with 5 degree steps for the critical temperatures.

Increased number of cooling unit parameters stored resulting in accurate history which makes the RV Tech's diagnostics job faster and easier. For example, if a wire has a short on it, it is reported for ease of troubleshooting.

The error reporting takes into account the cleanliness of the power supply which can be an issue on many RV's. The RV industry has coined the term "clean power", thus we make sure that the delivery of power to your fridge is reported in a manner that can be used to confirm power issues that affect your fridge. This function has been moved to the main display so the end user can easily check their own power without special equipment.

We are sorry to say that these features are not available on the older ARP Control.

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RV Circuit Protection
#9 Circuit Breaker (5 Amp) $5.50

We recommend the purchase of this circuit breaker with the ARP Control purchase. Many RV manufactures do not protect their refrigerators correctly. Often the refrigerator is on a 15 or 20 Amp fused circuit because one fuse is designed to protect both the fridge and other appliances such as the furnace. This circuit breaker is required to protect the ARP Control and the refrigerator in this case.

This 5 Amp circuit breaker will trip at around 8 Amps, protecting the ARP Control and the fridge it is connected to. When the breaker trips it is apparent because the reset button sticks out from the normal position. When wiring, please note that there is a "LINE" terminal that the 12VDC power source is connected to. There is also a "LOAD" terminal that is connected to the ARP Control red wire, or any device that needs to be powered in your RV.

The dimensions given in the drawing are millimeters. The terminals are standard 0.25" male spade connectors. Again, the terminals are polarized meaning that the power and load have designated locations marked on the case.

Total Dimensions

Fridge Defend Front Dimensions Fridge Defend Side Dimensions

Fridge Defend Housing: 4.06" x 2.07" x 0.57" (inch)

Blower Fan: 4.72" x 4.72" x 1.26" (inch)

Circuit Breaker: 2.18" x 1.38" x 0.57" (inch)

These images give all of the dimensions (inch) for the Fridge Defend when combined with the Quiet High Performance Blower Fan and the Circuit Breaker sections above.

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