DM2852 • DM2862 • DM2872 • RM2807 • RM2811 • RM2812 • RM2820 • RM2852 • RM2882 • DM3862 • RM3862 • RM3962 • RM3972 • RM4804 • RM4872 • RM4873

Dometic 8 & 9 Cubic Foot Cooling Units

The Dometic 8 and 9 cubic foot fridges are found in both Class-A and Class-C motorhomes. In addition these excellent fridges are also found in many Fifth Wheel RVs.

The Dometic cooling unit design is very efficient when compared to other cooling units, but there is a trade-off for efficiency, these cooling unit are vulnerable to boiler overheating that can result in a damaged refrigerator, or even worse, a fire. Click here to see how the ARP helps prevent these problems.

This photo shows a typical Fridge Defend installation within the cooling unit compartment. The Fridge Defend is mounted directly to the Dometic control box. Please see below for wiring diagrams by refrigerator model.

Airstream RM2862

This photo is a Dometic RM2862 with the Amish cooling unit installed in an a Airstream trailer. The owner of this fridge led Airstream caravans. This gentleman went through a number of refrigerators, both new and rebuilt. When he found out about the Fridge Defend by ARP he was intrigued to say the least.

One issue with the Airstream trailer is the distance the fridge is mounted from the vent. We highly recommend the Fridge Defend + Fan Control for this application.

Install Boiler Sensor

This photo is a Dometic RM3962 boiler, all of the 8 and 9 cubic foot fridges have similar boilers. The two green arrows show a crimp that is put into the boiler tube to hold the inner percolator tube in place. Do not place the tip of the ARP temperature sensor (blue arrow) so it straddles the gap resulting from these crimps.

Please be careful to position the ARP temperature probe away from the flue tube (red arrow). In addition, fill the area around the temperature sensor with insulation so that the area between the black arrow and the flue tube is packed. If there is a gap between the temperature sensor and the flue tube, the heat from the flue tube will give the temperature senor a false reading thereby preventing the control from functioning properly, thus fill all gaps with insulation.

Click here for temperature sensor install video.

This photo is of a Dometic RM3663, it is similar to the above photo, but it shows more detail of the cooling unit compartment.

Please note the heavy power wires on the right side of this photo. Please be sure to always insulate these wiring harnesses that run through the cooling unit compartments. The heat from the cooling unit can melt the insulation on the wires, thereby causing an electrical fire. Yes, not all fires that originate in the cooling unit compartment are due to the boiler of your fridge overheating!

Wiring ARP Control on 8 and 9 Cubic Foot Dometic Fridge

RM2807; RM2811; RM2812; RM4804; RM4872 (Early 2-Way)

Please click here for the details of wiring the 2-way models without the boiler thermal switch recall.

RM2852; DM2852; RM2862; DM2862; RM3862; RM3962 (Late 2-Way with Recall)

Click here if your fridge has a boiler thermal switch that is wired in line with the power supply.

RM2807; RM2811; RM4804 (Early 3-Way Models)

For the early 3-way models where all of the current is routed through the power supply to the fridge control. The ARP can not power the 3-way heater and a relay is required.

ARP Fan Install

Please click here for the ARP blower fan and temperature sensor installation.

Please see the full ARP User Manual and Installation Guide for more information needed before using your ARPrv Control.