Dometic Refrigerator no cooling when plugged into electric

[7138]

I have a 2003 Travel Supreme motorhome. I'm having a problem with my Dometic refrigerator, model NDR1062. It's not affecting the freezer, which is working fine, just the refrigerator. Both refrigerator and freezer work fine on propane. But, when plugged in to electric, the refrigerator portion does not get cool or cold.



Any ideas? Has anyone else had this issue?

Thanks,
Jerry

[Fridge Defend]

Originally Posted by 7138

I have a 2003 Travel Supreme motorhome. I'm having a problem with my Dometic refrigerator, model NDR1062. It's not affecting the freezer, which is working fine, just the refrigerator. Both refrigerator and freezer work fine on propane. But, when plugged in to electric, the refrigerator portion does not get cool or cold.



Any ideas? Has anyone else had this issue?

Thanks,
Jerry

If the fridge works fine on LP gas, you should discontinue use on 120VAC because you can damage the fridge.

It sounds like your electric heater has failed, the ohms of the heater need to be tested. We have that information posted on our website, just ask and we can send you to find that info.

Here to help

[kewag]

There is a fuse in the control board. Also heating elements in the stack. Download the manual and see what ohms the heating elements should be.

[Old-Biscuit]

Your NDR1062 uses One 325W 120VAC Heater Element 2.7A when energized with 44ohms resistance


Verify you have 120VAC at the outlet
Verify you have 120VAC J5 (Hot) & J6 (Neutral)
Verify you have 120VAC to/thru the 5A Glass Fuse (above J5)
Verify you have 120VAC at J7 (Neutral) & J8 (Hot) terminals on Lower circuit board WHEN fridge calling for heat cycle (Food compartment warm)


Dometic 3850644422 (new part number for a 325W 120VAC Element)
https://www.dyersonline.com/dometic-...g-element.html

[7138]

I appreciate the replies! I am a bit confused though. If the heating element is bad, then why does it work on propane? And why does the freezer work on both propane and AC? I would think if the heating element was bad, then the freezer wouldn't work either?



Someone suggested it may be a clogged line, and it works on propane because that's hot enough to get thru the clog. What do you think?


I don't really have the skill to check the ohms myself


Thanks,
Jerry

[Capacitor]

Can you test for 120vac at the locations old biscuit indicated?

[Old-Biscuit]

Originally Posted by 7138

I appreciate the replies! I am a bit confused though. If the heating element is bad, then why does it work on propane? And why does the freezer work on both propane and AC? I would think if the heating element was bad, then the freezer wouldn't work either?

Propane and Electric are 2 Separate heating sources. So electric could work and propane not or as in your case, propane works but electric doesn't.

Freezer COLD but food compartment not on Electric......due to element not generating enough heat to boil sufficient ammonia vapor to cool BOTH freezer and Food Compartment.
*Freezer is First in process ----so there has to be enough absorption available after freezer in order to cool food compartment.



Someone suggested it may be a clogged line, and it works on propane because that's hot enough to get thru the clog. What do you think?


Obstruction/blockage.........NO cause propane cools both freezer and food compartment and there is only ONE cooling unit regardless of heat source

I don't really have the skill to check the ohms myself


Thanks,
Jerry

Ohms Test
Turn fridge OFF
Unplug the AC Heater Element Leads from Lower Circuit Board
*J7 & J8 terminals
Set the voltmeter selector dial to Ω.
Place Red Probe on end of one of the leads
Place Black Probe on end of other lead
Observe the readout window to obtain the Ω reading.

44ohms

[7138]

Thanks so much. That's is very helpful - and makes sense!

[Fridge Defend]

Originally Posted by 7138

I appreciate the replies! I am a bit confused though. If the heating element is bad, then why does it work on propane? And why does the freezer work on both propane and AC? I would think if the heating element was bad, then the freezer wouldn't work either?



Someone suggested it may be a clogged line, and it works on propane because that's hot enough to get thru the clog. What do you think?


I don't really have the skill to check the ohms myself


Thanks,
Jerry

Hi Jerry, great questions:

1) "I am a bit confused though. If the heating element is bad, then why does it work on propane?"

The fridge boiler, which produces the refrigerant is powered by heat.
Both the heating element and the propane do the same thing, they provide the correct amount of heat to power the boiler in your fridge.

2) "And why does the freezer work on both propane and AC?"

The boiler is producing enough refrigerant to cool the freezer in booth modes of operation. But the heating element has an issue that results in low heat to the boiler. This low heat not only does not produce enough refrigerant, it will over heat the boiler eventually, thereby destroying the fridge.

Click on the below post, this person had the same issue, but it was on propane rather than electric:

But who can explain the following?

We are here to clear up misunderstandings about Dometic and Norcild refrigerators.

It is by knowledge that we can fix stuff

[wopachop]

Originally Posted by Fridge Defend

But the heating element has an issue that results in low heat to the boiler. This low heat not only does not produce enough refrigerant, it will over heat the boiler eventually, thereby destroying the fridge.

How does the low heat issue eventually end up overheating?
Does it have to do with not cycling off? A constant low heat instead of a short blast of high heat followed by turning off.

[SeaBreazer]

Low heat cause the liquid in the boiler to boil but not vaporize.
The best wat I can describe it is a pot of water on the stove. If the pot of water is brought to a slow boil it has small bubbles very low steam or vapor coming off the pot.
If you bring that same pot to a rapid boil it produces a lot of steam or vapor coming of the pot.
So to put in the the refrigerator system as in the rv fridge. If the heater does not got hot enough to truly vaporize the solution in the boiler to the smallest vapor particul possible it builds pressure in the boiler and causes the boiler to expand and crack the seams and leak the solution which is a potential for a fire due to the gasses it will emit.
That is the best I can explain in layman terms.

[Fridge Defend]

Originally Posted by wopachop

How does the low heat issue eventually end up overheating?
Does it have to do with not cycling off? A constant low heat instead of a short blast of high heat followed by turning off.

The following in on the right track, but the science needs to be tweaked a little for accuracy:

Originally Posted by SeaBreazer

The best wat I can describe it is a pot of water on the stove. If the pot of water is brought to a slow boil it has small bubbles very low steam or vapor coming off the pot.

If a picture is worth 1000 words, a video is worth 1 million

In the video below, please note that when the Norcold or Dometic boiler starts operating properly, the boiler pump starts the refrigeration process by boiling the ammonia. This would be with the correct heat input, not too little and not too much. I think we should call this the "Goldilocks Boiler Syndrome" (there, I coined another term like "quality of heat".)

This is where boiler operators get confused, the Goldilocks Boiler Syndrome will never occur in a ship or power plant boiler for example.

This is because the Dometic or Norcold boilers basically preform two tasks, where ship and power plant boilers only preform one task.

If the boiler does not have enough heat, the boiler pump never starts. See this thread: PRESSURE TEMPERATURE VIDEO. This is shown in the video below.

If the boiler has too much heat, well we do not need to go into too much detail, but the failures that destroy your fridge also occur. This is why one needs to control the boiler temperature on an absorption fridge, which the recalls and subsequent measures do not address.

https://www.youtube.com/watch?v=3JB0QyPvEAo