Dometic Fridge Problem in a brand new unit

[sdtravis]

We have a 2021 Dynamax Isata 3 with a Dometic DMR-702 refrigerator that is acting up and could use some help from all of you experts on this topic. I have a request in to a warranty dealer to help with this, but did my own investigative work on this ahead of time in case they can't figure it out. (and dealer service is booked out months, so hoping to find a cure on my own and avoid the delay).

Here's the scenario: When refrigerator is on propane, the panel will eventually light up an error code and shut the refrigerator off. The error code is always the same -- two blinking lights, 1) LP AND 2) Temperature setting (important detail -- the error blinks whatever the setting is currently set to, not a specific LED). The troubleshooting manual calls out a series of error codes, but given that the LP light flashes AND the temperature led flashes, I'm thinking this is the warning condition where LP is not lighting.

This condition is not easily repeatable, and it oddly happens in the middle of the night, also when unplugged from shore power. When turning fridge off and on repeatedly it will relight flawlessly.

Fridge works on AC, no issue.

Batteries are 99% SoC throughout the night, BMV shows no voltage drop or issues.

Propane tank is full. Other gas appliances work perfectly.

Original thermal cutoff fuse has continuity.

Original thermistor tests resistance in spec.

As a last resort, I replaced the control board with a brand new board, no change, but at least now I have a backup board!

I ran one test to turn off the propane at the tank while the fridge was on -- this produced the same error condition on the display panel, leading me to believe this might be something related to propane flow or something along those lines.

What else should I test or consider? Bad propane regulator somehow killing the propane under cold conditions? Misadjusted regulator? Bad eyebrow board?

Specs:
Model: DMR702
Product: 936002904
SKU: 9600010870

[Old-Biscuit]

The error code is always the same -- two blinking lights,

One is LP
*Gas ignition failed. The gas flame has not been ignited after 45 seconds.

Other -- Temp Setting 1-3
1) *Disconnected gas valve or hardware fault in the gas operation system. (Check the Wire Connections ON Gas Valve and ground connection J1 Position on Circuit Board)
(Check the Spark Electrode wire connection/ceramic insulator for cracks and electrode position/gap over burner)
2) *A faulty temperature sensor device or a fault in the associated electronic circuitry has occurred. (that would be Thermistor connection or the circuit --- J3 Position on Circuit Board)
3) *DC voltage is out of range (drops below/exceeds the limit values approx. 8-18V DC). Very Wide Range on DC Voltage


Suspect #1
Spark Electrode is DUAL Function....provides High Voltage Spark for Ignition AND Return path for Flam Proving Signal (Current generated by flame ionization ---circuit board senses this current/keeps DC on gas valve. No signal/DC to gas valve dropped/error code triggered
Current is only a few milliamps so doesn't take much to stop it/go to ground

Installation & Operating Manual

[jkwilson]

Make a manometer and check your LP pressure. It’s a very useful tool and checking the pressure should be done annually and before a trip.

[wa8yxm]

I do not think this is your problem but.....
In the outside compartment is a ribbed, likely black but may be white, tube with a plug in the lower end.
This end is SUPPOSED to be put through one of the vent holes in the outside cover so it drip-drip-drips on the ground-ground-ground.

on mine, when new it was not. and as it happned right below the tube is an electrical terminal board (NOT the control board) where it Drip-Drip-Dripped on.

I put it out

Then there was a Recall on my unit (this is 15 years ago) so I returned to dealer and the Was telling the service consultant how I had to put it out as the techinican having finished the job returned my keys.. he said "I always put it out".... Guess what I found immed on return to RV.. Yup.. I put the tube out and returned to my travel .

Since you have a dometic. You need to know this. I doubt it's your problem but. Depending on just where it drip-drip-drips.. who knows.

[opnspaces]

Probably not related, but is there a bunch of yellow powder accumulating on the back of the refrigerator? Mind acted similarly when new and there was a leak in the cooling unit.

[2112]

Turn on the fridge and water heater on propane, light 1 stove burner and see if the stove flame level fades away. This should test the integrity of your regulator.

[2oldman]

newman fulltimer wrote:
Sounds like yOu have moisture in the propane line and at night its freezing up causing a no light issue.

Kinda doubt that if he's in Encinitas. Just out of curiosity, how does moisture get in a propane line?

[newman_fulltime]

Sounds like yOu have moisture in the propane line and at night its freezing up causing a no light issue.You need to purge your lines and get the moisture out of them

[2oldman]

Difficult to imagine a brand-new unit failing like this, but I think you're on the right track with the propane supply.

Propane regulators do fail. Replace it.