Refrigerator Too Warm

[JRMunn]

After the knuckle busting task of changing a furnace motor, I have tried not to be learning something new about my 2004 Sunnybrook 5th wheel for a while. But I have been putting up with a refrigerator problem that needs to be taken care of before the summer heat arrives. There is no shore power where the trailer is parked, so I have the refrigerator running on propane. It has separate freezer and refrigerator compartments. The freezer part seems to work fine, but the refrigerator is too warm. I have tried moving the temperature sensor up and down on the refrigeration fin without seeing much change in temperature. The refrigerator is a Dometic model no. RM2862 with a product no. of 921 14 60-96. Any suggestions about how to solve this temperature problem would be greatly appreciated.

JR Munn

[ReneeG]

I'm not wopachop, but am the one who mostly monitors the fridge performance and starts it up for a trip. Running it on shore power, it takes longer to cool than running it on propane. On propane it runs much colder and cools down quicker. We have a Dometic.

[JRMunn]

wopachop - Jugs might be an option if my return schedule was more certain. But my experience with drained batteries (which shut off the refrigerator and take a long time to re-charge) and propane use advises otherwise, and I don't even want to think about mold. Is it your experience that it takes longer than overnight for the refrigerator to cool down?

JR Munn

[wopachop]

Dang might be cheaper just to leave it running? If i was in your situation i would fill up some 1 gallon water jugs and put them in both the fridge and freezer. Turn off the fridge when you leave but keep the fridge doors closed and let the water jugs maintain temp.

The fans are a very small power draw. I personally would avoid the battery powered stuff. Waste of money when you have 12v all over the trailer and even inside the fridge. My fans are powered off the fridge light circuit.

[JRMunn]

Wopchop - Thanks for advice about fans. I hope I don't end up with 4 fans - sounds like significant draw-down on the battery. My routine is to turn refrigerator off when I leave (with doors cracked open and without anything in it that spoils or melts) then start it up as soon as I return, which could be a few days. I found a couple of thermometers at home to see starting temperature, will look again after it runs overnight, then switch thermometers to see if I get similar results. With this as a baseline, I can start following up on the many suggestions for sources of problems.

JRMunn

[wopachop]

Yup bring a square tip on the roof and remove the cover to check that there is not a big gap of open space next to the fins. My fridge ran warm and it turned out my clearances were OK.

Problem for me was lack of airflow behind the fridge. It comes with a tiny fan but its not enough on hot days. My manual even has a section about adding another fan to help blow the hot air out of the roof vent.

I ended up with 4 12v fans.
1 large (4") fan is behind the fridge to blow the hot air out. I only use that in the summer.
2 fans blow at the cooling fins inside the fridge.
1 fan sits in the middle of the fridge to circulate that air.

Mine are Noctua brand and come with adapters to reduce the RPM. For me the biggest help was adding a fan to blow at the cooling fins inside the fridge.

[JRMunn]

Thank you enblethen for the Manual. It helps to see the instructions and diagram. I have put it in my trailer folder, both on the computer and printed a copy for in the trailer. I will check clearances. And I will check freezer and food compartment temperatures. I can move the temperature setting to 5, but figured that would be for hot climates in the summer instead of when the heater is needed.

JRMunn

[Old-Biscuit]

Temp setting is basically for food compartment temps

Freezer temps NEED to get to 10*F and lower in order for food compartment to effectively cool down

Freezer Coil is 1st in the cooling process so the colder the freezer is the more cooling capacity is available for the food compartment

[enblethen]

Many refers are not installed per manufacture manuals. Look on page 7 of this Manual
Area above refer should be blocked off. I used a piece of round metal duct to form a deflector. I did it while cleaning the flue.
I used foam board glued to outside of the rig to narrow spave between coils and exterior wall.

[JRMunn]

Thank you for all the helpful suggestions. I had not checked for coolant leakage, but I will, because the freezer seems to work fine and my experience with propane refrigerators has been with older models. I don't know about clearances and the trailer didn't come with a manual for the refrigerator. The refrigerator is original, so I hope it was installed correctly. The trailer is level, or very close to it. I am reasonably sure of the 12 volt source. Since I use propane, I think the DC line is for the control board and light. I have inspected the seal, but not tested it. How is this done? I have the adjustable temperature set at 4, but it has been long enough since I measured temperatures that I can't remember them - only that the refrigerator section seemed too warm. I hesitate to set the temperature adjustment lower since the freezer seems to be working fine - makes ice in just a few hours. I will measure temperatures again with a better thermometer and then see what happens when the thermistor is unclipped. I will also check to make sure I have a blue flame from the burner. Thank you again for the many suggestions.

JRMunn

[pianotuna]

JRMunn wrote:
But I have been putting up with a refrigerator problem that needs to be taken care of before the summer heat arrives. There is no shore power where the trailer is parked, so I have the refrigerator running on propane. It has separate freezer and refrigerator compartments. The freezer part seems to work fine, but the refrigerator is too warm. I have tried moving the temperature sensor up and down on the refrigeration fin without seeing much change in temperature. The refrigerator is a Dometic model no. RM2862 with a product no. of 921 14 60-96. Any suggestions about how to solve this temperature problem would be greatly appreciated.

JR Munn

Does it cool well on 120 volt shore power? If not, then you may have a blockage in the tubing.

You may, or may not have success by taking the fridge out and tipping it upside down, etc.

If that fails to improve cooling then the cooling unit may need replacement.

I would move to a compressor instead of an absorption fridge.

[Old-Biscuit]

1st off is fridge being operated LEVEL?

2nd thing is that Model (RM2862) has 'adjustable temp setting' (1-5) so thermistor should be in OEM position as that is where thermostat is calibrated for the temp setting range
**Fridges that use the 'Auto Temp Control' (no temp setting) you can move thermistor UP/DOWN for minor affect on overall temps

What temp is Freezer holding?
What temp is Food Compartment holding?

12VDC is needed for Controls, Display Panel and fridge functions on Electric/Propane

One simple test is to remove thermostat/clip from fin and let it dangle so it is just hanging
No temp sensing of FIN the thermostat will run fridge continuously
**Freezer/Food Compartment should get VERY Cold after 12hrs of running w/o thermistor sensing

Freezer getting COLD (10*F or lower) and food compartment NOT could be:
*Off level operation
*Thermistor
*Gas pressure/dirty burner
*Circuit Board
**CLOGGED Cooling Unit (between freezer coil and food compartment coil


SO
Answer the questions about temps
Try 12 hr run W/O thermistor

Post back

[bob213]

Have you done the door seal test? A fan in the frig section can help to move the air around.
Frig needs 12v all the time when on propane to run control board.

[ReneeG]

midnightsadie wrote:
you do need a good solid 12v to the frig at all times. take outside vents off look for yellow resado ,,nice bright blue flame.?

I'm not sure about the 12v to the frig at all times. It will draw what it needs for control power from the batteries and the rest from propane when set that way. We boondock or dry camp the majority of the time only using 12v (plugged in to 30amp) on the fridge when cooling it down when we're getting ready for a trip (or we run it on 12v powered by our solar en route).

[ReneeG]

I know you said you adjusted the fins up and down, but what about the temp setting control? Ours ranges from 2 - 5 and the higher the number, the colder the temp in the fridge. Freezer seems to be freezing no matter what temp. I panicked when I set the temp to 2 and it was getting warmer and not colder, on propane.