Dead Dometic RM8501

In recent years Dometic has engineered a new type of cooling unit that utilizes an improved siphon pump tube design which drastically reduces the possibility of permanent damage to the coils if operated in an out-of-level condition, or too much heat is generated at the boiler section. As we can see from this drawing, the siphon pump tube is enclosed in the design and is surrounded by a weak ammonia solution, which will protect the pump tube from abnor- mally over-heating. This type of unit; however, does not eliminate the need for proper leveling. The unit still requires gravitational flow to provide the proper cooling process, and if leveling is outside the necessary limits, cooling will dramatically slow down or stop completely. The cooling coils are not normally damaged in this fashion and once proper leveling is main- tained, the cooling process will resume.

Spirit or bubble levels are no longer being supplied with the new style refrigerators as the RV or vehicle only needs to be leveled so it is comfortable to live in, with no noticeable sloping of the floor or walls. For diagnosis, the new style cooling units that incorporate the protection boiler system, can be differentiated from the older style coils by the shape and design of the outer boiler box cover on the rear of the cooling unit. These units will incorporate a circular metal cover,

while the older style utilizes a square shaped enclosure. We will discuss diagnosis and troubleshooting of these units in more detail later in the program.