Dometic DMR702. No error codes. On shore power or propane, fridge\freezer cools down. Seems to work great during the day. Temps 34'ish and -2.5'ish, right on target. Overnight, the temps go up a bit.. 42-45, 8-10. As the day warms up, the fridge gets going to bring the temps back down. - I did the "unplug from controller board, 120v directly plug in the AC heater" test - brought the temp right in line.- I replaced the tank pigtails and the switching propane regulator (it was not putting out enough propane to support all devices). Tests out fine now.- I replaced the igniter\thermocouple.. was time to replace it.- The flame is a nice blue quarter sized -- looks great.It seems something is telling the controller, the temp is good. Any thoughts are greatly appreciated.

Did you uplug the thermocouple to see if the fridge goes into the emergency cooling mode?

Could it be related to the auto defrost setting? Do you have a little thermometer in there tracking temps? The graph could tell you a lot about how often and how long the cooling cycles last.

That model does not have 'defrost' modeThat model is equipped with an automatic Low Ambient Control (LAC) function *turns food compartment light ON when ambient air temps drop below 50*F ---- no on/off switch (light causes a heat load so thermostat calls for longer heat cycles/colder tempsThat model only has 3 temp setting.....narrow range controlYou have proven cooling unit functions properly (Direct wiring of element)SO......Unplug the thermistor leads from lower circuit board (P2 connector at J3 --- S/B white leads)Run fridge overnight w/o thermistor sensing and fridge temps should go down and stay downIf they do replace the thermistorSnip-The-Tip Rheostat thermistor replacement

For $29, I'm just replacing the thermistor. New snip the tip on the way. Back to you all soon. Thanks for the advice.. FWIW, I installed Fridge Defend by Arp with internal and external fans to provide more safety\control of the burner... lovin' that device

I would be inclined to think the outside coils and stack need cleaning. This is described more or less in your owner's manual. I've never done it. Sun heat on the outside increases air flow up through the coils is my guessI'd remove upper and lower covers, blow air DOWN (Carefully and straight) to clean the coils Make sure the coils do not end and close off. Stack cleaning is described in the manual I hope.

Fridge warming up overnight | Good Sam Community

MalibuDave42
Explorer
Sep 25, 2020
Old-Biscuit, a question about your Thermistor test. When you unplug the Thermistor, the control must be reading the temp as "too warm, keep running." Is this correct? If yes, does this mean the boiler\refrigerant runs continuously until there is manual intervention (aka it's manually turned off)?

How will this test answer the question about not staying cold overnight?

WRT to Snip-the-tip. It will be no problem to install. But, how will I know if it is working? Should I monitor the temp, keep adjusting the dial until the temp is correct?

Thanks for your insights
Old-Biscuit
Explorer III
Sep 22, 2020
wa8yxm wrote:
I would be inclined to think the outside coils and stack need cleaning.
This is described more or less in your owner's manual. I've never done it.

Sun heat on the outside increases air flow up through the coils is my guess

I'd remove upper and lower covers, blow air DOWN (Carefully and straight) to clean the coils Make sure the coils do not end and close off.

Stack cleaning is described in the manual I hope.

OP posted fridge works great during daytime BY+UT warms up at night
*night ---sun goes day ambient air temps drop

Re-read OPs 1st post
wa8yxm
Explorer III
Sep 21, 2020
I would be inclined to think the outside coils and stack need cleaning.
This is described more or less in your owner's manual. I've never done it.

Sun heat on the outside increases air flow up through the coils is my guess

I'd remove upper and lower covers, blow air DOWN (Carefully and straight) to clean the coils Make sure the coils do not end and close off.

Stack cleaning is described in the manual I hope.
MalibuDave42
Explorer
Sep 21, 2020
For $29, I'm just replacing the thermistor. New snip the tip on the way. Back to you all soon. Thanks for the advice..

FWIW, I installed Fridge Defend by Arp with internal and external fans to provide more safety\control of the burner... lovin' that device
Old-Biscuit
Explorer III
Sep 21, 2020
That model does not have 'defrost' mode
That model is equipped with an automatic Low Ambient Control (LAC) function
*turns food compartment light ON when ambient air temps drop below 50*F ---- no on/off switch (light causes a heat load so thermostat calls for longer heat cycles/colder temps
That model only has 3 temp setting.....narrow range control

You have proven cooling unit functions properly (Direct wiring of element)

SO......
Unplug the thermistor leads from lower circuit board (P2 connector at J3 --- S/B white leads)
Run fridge overnight w/o thermistor sensing and fridge temps should go down and stay down
If they do replace the thermistor

Snip-The-Tip Rheostat thermistor replacement
wopachop
Explorer
Sep 21, 2020
Could it be related to the auto defrost setting?
Do you have a little thermometer in there tracking temps? The graph could tell you a lot about how often and how long the cooling cycles last.
rrupert
Explorer
Sep 21, 2020
Did you uplug the thermocouple to see if the fridge goes into the emergency cooling mode?

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