Dometic Fridge not working

[motc777]

Hello:

Came back from out of town, and the fridge and freezer portion were not working. Now, I do have power, in that the light comes on. Typically we run on electric power. So on electric, I do not have a check light, but when I switch to Propane (which I've never run in that mode before) the check light comes on.

I do not smell ammonia. Prior to this, I was having problems with the fins freezing up, and I think that is the sign of a bad thermistor on the fin. I have checked fuses on the front panel and the rear fridge, but none are blown.

I can tell you it looks like this may have just gone out in the last 24-48 hours because the freezer portion had frost still in it.

Do I just have a bad thermistor or what?

Model: RM2652

[jkwilson]

Any chance you got the wrong element? I believe yours should measure 44ohms.

[dougrainer]

motc777 wrote:
OK about an hour ago, I decided to try Propane mode. I checked outside and sure enough, the burner fired right up. After one hour, I checked the pipe stack and the coils on the back. Both are warm. With the unit on electricity using the heating element, only the stack got warm, and never the coils on the back.

It's been close to 1.5 hours, and in the freezer, what little water drops have frozen.

I guess the real test ill be in the morning after it's run all night tonight. But, for the sake of argument, if this unit runs on propane, but will not work on electricity only (i.e. Auto) and reminding everyone I just put in a brand new element, what could it be?

Control board?

NEVER a control board. All they do is switch between LP and 120 and monitor the cold for the Thermister. ARE you POSITIVE you put the correct wattage Heat Element in? They are not all the same. In extreme rare cases the heat element tube is not attached securely to the burner flue. NO problem on a Dometic as Dometic has 2 heat element sleeves. If you suspect this you just move the heat element to the other sleeve. To verify the Heat Element wattage you either look at its stamped display on the element or you do a AMP check. The amp check will tell you the wattage. Doug

[motc777]

OK about an hour ago, I decided to try Propane mode. I checked outside and sure enough, the burner fired right up. After one hour, I checked the pipe stack and the coils on the back. Both are warm. With the unit on electricity using the heating element, only the stack got warm, and never the coils on the back.

It's been close to 1.5 hours, and in the freezer, what little water drops have frozen.

I guess the real test ill be in the morning after it's run all night tonight. But, for the sake of argument, if this unit runs on propane, but will not work on electricity only (i.e. Auto) and reminding everyone I just put in a brand new element, what could it be?

Control board?

[tewitt1949]

I just replaced my with a house fridge. So far happy.

[MEXICOWANDERER]

Need numbers to help diagnose please

[motc777]

OK I replaced the heating element. Note: The previous one, there was zero heat coming from the pipe. Well, I put the new one in, instantly, it's getting hot. Then I noticed that the freezer portion was starting to get cold. I left it overnight thinking this was going to be resolved.

However, I woke the next morning and the freezer is somewhat cold, but not normal cold. The fridge portion, the fins feel cool, but not cold like normal.

The thermistor is slid all the way up on the fin.

I do not smell, nor see any ammonia on the back coils. What's my problem? Bad unit?

[wa8yxm]

Just had a member in another group "Fuses good. No lights. No cold"

Had her unplug and replug everything in the black box on the lower left outside and on the "Eyebrow" (The light panel just pulls off toward you) and .. Back in business. NOTE this is a "NO LIGHTS" situation.

NOTE low battery will do it too.

[dougrainer]

1. Fins freezing up is NORMAL. The fin temp will be 10 degrees colder than the refer. So, if the refer is 36 degrees the fins are 26 degrees which will cause ice on the fins depending on the humidity.
2. Check light, You need to cycle the refer 7 to 10 times to remove any air in the LP line to the refer. The refer should light unless your burner is extremely dirty which should be cleaned.
3. What fuses on the front panel????? There are no fuses on the front panel
4. AS others have stated, if the flue cover is COLD. Starting on 120 and wait 1 hour. The flue cover will be warm/hot. If so the element is GOOD. No other testing of the element is needed. They either work or do NOT work. No middle ground. Doug

[Old-Biscuit]

Turn fridge ON in AUTO with AC Power hooked up

GO to outside compartment and feel 'stack' area where the 2 leads go into shield
Area should warm up noticeably IF element is working


The element leads (black) connect to circuit board at J7 & J8 terminals

[garym114]

Video for testing, checking fuse and replacing element.
https://www.youtube.com/watch?v=7KMHamcidMo

[MEXICOWANDERER]

BE CAREFUL!

Disconnect shore power, shut off propane

Get a handheld multimeter

Select RESISTANCE OHMS 1,000 ohms scale

Disconnect pair of wires that go into insulation on the vertical tube on the right side. These two wires are the AC power wires that go to the heater.

Disconnect the harness at the plastic disconnect coupling.

Turn meter on. and double check ohms again.

Touch the red and black test lead points together

Meter scale goes from blinking "1" to solid "0" right?

Touch red wire to one of the two wires LEADING TO THE HEATING ELEMENT

Touch the black wire to the OTHER wire leading to the heat element

What reading do you get?

Keep testing

Set meter to AC (NOT DC!) volts.

Reconnect shore power insure you do have shore power inside the rig.

Go to refrigerator. Do you now have power to the refrigerator? Good

Take meter with you. Remember it is to be set to AC volts 200 volt scale.

Remember the 2 connections you tested with the ohm meter?

This test has nothing to do with those 2 wires.

This test has to do with the other side. The twin wires you did not test.

BE CAREFUL you are working around live 120 volts AC

Keep your fingertips AWAY from the test lead metal points

Same type of test

One meter probe to one wire the 2nd meter probe to it's twin.

How many volts do you see?

Check back on the forum with the results of your meter testing.

[2oldman]

Coils get warm when working.

[motc777]

Old-Biscuit wrote:
Display panel lights, interior light etc....ALL 12V DC

Electric doesn't use the 'check light'---that is only a function of propane side

If you have fridge in AUTO it will select AC as priority
No AC available it will swap to 'gas'...if gas fails to light/prove 'Check' Light comes on

In AUTO and fridge remains on AC the AC power is available, AC Fuse on circuit board is good BUT electric element is bad cause no cooling is happening
OR the cooling unit has fail (blockage)

If thermistor/preset thermostat fail then fridge goes into LIMP Mode....CONTINUOUS cooling which will freeze both freezer and food compartment

Sounds more like the electric element has failed
325W element.....44 ohms....2.7A when energized

Ok where or how do you replace the electrical element?

[motc777]

2oldman wrote:
You do not smell ammonia, but have you opened the back and looked? Are the coils warm/hot?

Coils are doing nothing. Not warm nor hot.

[Old-Biscuit]

Display panel lights, interior light etc....ALL 12V DC

Electric doesn't use the 'check light'---that is only a function of propane side

If you have fridge in AUTO it will select AC as priority
No AC available it will swap to 'gas'...if gas fails to light/prove 'Check' Light comes on

In AUTO and fridge remains on AC the AC power is available, AC Fuse on circuit board is good BUT electric element is bad cause no cooling is happening
OR the cooling unit has fail (blockage)

If thermistor/preset thermostat fail then fridge goes into LIMP Mode....CONTINUOUS cooling which will freeze both freezer and food compartment

Sounds more like the electric element has failed
325W element.....44 ohms....2.7A when energized