Chuck_Sorensen
Jul 01, 2014Explorer
Dometic RM 8505 Refrigerator – Partial Cooling on Propane
On a recent camping trip our refrigerator went into a partial cooling mode while on propane. 120 vac and 12 vdc worked well. After our local Dometic Service Center serviced the unit it was again cooling properly; but no cause for the previous partial cooling was identified.
I checked the unit in our driveway over the next week; it cooled just like it had for most of the past two years; great. What I saw when things seemed to be working correctly: A full blue flame that filled the observable space in the burner. The flame would stay full until the selected refrigerator temperature was reached, and then it would shut off for a while. When the box temperature came up a couple of degrees, the flame would be reignited and run until the selected temperature was again reached. For the conditions when monitored the flame was on full for 1 hour and off for ½ hour. The condenser fans would cycle on and off. The upper flue temperature was typically 400 degrees F. while the flame was burning.
Mid June, we headed off on a camping trip and after 3 days the unit was back to 27 degrees F. in the freezer and the refrigerator drifting around in the 50’s depending on the outside temperature. We bought an ice box to continue our trip.
On returning home, I started the refrigerator many times. It was not cooling enough. 27 degrees F. in the freezer and the refrigerator section in the 50’s depending on the outside temperature. The burner flame was about half the size of the full good working flame. The burner never shut off. The condenser fans never ran. The selected refrigerator temperature setting was never reached. The upper flue temperature was typically 350 degrees F. and lower. Not enough heat to push things around the closed system.
On one last start up of the refrigerator, the flame came on large and the flue temperature was around 400 degrees F. I left it running over night and in the morning, the refrigerator section was at 22 degrees F. and the full flame was still going. The blue LEDS in the refrigerator were flashing; do not know if it was too cold for them or the control system was having problems. I tapped on the refrigerator’s gas valve and the flame immediately dropped back to its half size with an eventual flue temperature of around 350 degrees F. The refrigerator settled back into its 50’s degree F. range; the failure mode.
Dometic would not let me talk to a technical person so that I could find out more about the gas valve assembly and how it is controlled.
Chuck Sorensen
Buellton, California
2012 PW Excel TS
I checked the unit in our driveway over the next week; it cooled just like it had for most of the past two years; great. What I saw when things seemed to be working correctly: A full blue flame that filled the observable space in the burner. The flame would stay full until the selected refrigerator temperature was reached, and then it would shut off for a while. When the box temperature came up a couple of degrees, the flame would be reignited and run until the selected temperature was again reached. For the conditions when monitored the flame was on full for 1 hour and off for ½ hour. The condenser fans would cycle on and off. The upper flue temperature was typically 400 degrees F. while the flame was burning.
Mid June, we headed off on a camping trip and after 3 days the unit was back to 27 degrees F. in the freezer and the refrigerator drifting around in the 50’s depending on the outside temperature. We bought an ice box to continue our trip.
On returning home, I started the refrigerator many times. It was not cooling enough. 27 degrees F. in the freezer and the refrigerator section in the 50’s depending on the outside temperature. The burner flame was about half the size of the full good working flame. The burner never shut off. The condenser fans never ran. The selected refrigerator temperature setting was never reached. The upper flue temperature was typically 350 degrees F. and lower. Not enough heat to push things around the closed system.
On one last start up of the refrigerator, the flame came on large and the flue temperature was around 400 degrees F. I left it running over night and in the morning, the refrigerator section was at 22 degrees F. and the full flame was still going. The blue LEDS in the refrigerator were flashing; do not know if it was too cold for them or the control system was having problems. I tapped on the refrigerator’s gas valve and the flame immediately dropped back to its half size with an eventual flue temperature of around 350 degrees F. The refrigerator settled back into its 50’s degree F. range; the failure mode.
Dometic would not let me talk to a technical person so that I could find out more about the gas valve assembly and how it is controlled.
Chuck Sorensen
Buellton, California
2012 PW Excel TS