This video teaches how to install the Fridge Defend boiler temperature sensor on left-hand boilers such as the Dometic RM1350.
Click here for another video showing ARP install on Dometic left-hand boiler.
NOTE: There is no need to get the sensor as high on the boiler as possible. This video was made when RV manufactures installed the refrigerators so one could access the boiler up to 4 inches above the heaters. We now recommend installing the boiler sensor just above the electric heater element. Be sure to insulate the sensor so that it reads temperature from just the boiler tube, not electric heaters or flue tube.
The first step is to identify the tubes within the boiler housing. The red tube is the flue tube, the black tube is the boiler tube. The boiler tube is where the ARP sensor (thermal sensor) is to be mounted. It is easy to identify the boiler tube because the electric heater mounts are welded to the boiler tube. In addition, most of the left-hand Dometic boilers have a series of crimps along the boiler tube.
There are two places that the ARP temperature sensor (thermal switch) can be mounted on the boiler tube for the left-hand Dometic boilers. The preferable location is on the flat part of the boiler tube one inch above the electric heaters. The ARP sensor must be below the second from top absorber coil, maximum height. After gluing the sensor to the clip in the correct orientation, use silicone grease on both the sensor clip and the boiler tube to make it easier to adjust the location of the sensor once installed. One must read the downloadable installation instructions.
Some of the Dometics with the left-hand boilers, it is not possible to mount on the flat part of the boiler tube. In this case one must mount the ARP temperature sensor on the crimped section of the boiler tube. Make sure that the tip of the ARP sensor is in contact with the boiler tube.
It is important to insulate the ARP sensor very well. Make sure to rotate the sensor away from the flue tube and then pack insulation between the flue tube and sensor. Be sure to insulate between the ARP sensor wire and the boiler tube. Also insulate the electric heaters and fill the entire boiler housing with insulation to make your fridge operates more efficient.
The Dometic left-hand boiler housing opening instructions are found at the following link: