HELP: Fridge issues and trip tmw!

[BurbMan]

Dometic fridge, we always keep a bag of ice in the freezer to help even the temps between trips. Last night went to put food in the fridge and it didn't feel very cold. Digital thermometer reading reveals fridge at 57* while freezer is at -15*! Control panel on top is set to #4 setting.

I also noted that the thermistor in the fridge slid down to the bottom of the fin. Would that cause the temp difference between fridge and freezer or is there something else I should check?

I raised the thermistor as much as I could but the cord is only long enough to get it about halfway up on the fin.

[BurbMan]

Looks like vent fan is DOA, but aux fan running doesn't help either. Current temps are 3* freezer and 60* fridge. Fortunately have an appt with National RV Refrigeration in Shipshewana, IN tomorrow at 8am. Will be a slight detour from our trip, but have used these guys before and they are the best!

I like to DIY stuff when I can, but you have to know when to call in the pros...will report back on what the fix was.

Disappointing part was that fridge was running on our maiden voyage last month, so went shopping for this trip thinking fridge was fine. Wound up tossing $150 of groceries in the trash because they sat all night at 57*. Hate to do it, and especially hate to waste food like that, but better than missing out on a $1000 trip due to food poisoning on the first night.

[BurbMan]

1. The Evap fins will be 10 degrees colder than the actual items in the refer. Where did you install the probe for your thermometer you purchased?
The fridge probe is stuck to the left side wall of the fridge between the 1st and 2nd shelf. Not too close to the fins, not to close to the bottom.

2. 120 elements either work or they do NOT work. No in between/partial operation.
Got that, thank you.

3. WAIT 24 hours before getting a reading
Would love to, but don't have a lot of time to get this diagnosed.

4. Have you verified that the unit is level, now, and when you started loading it up for your trip?
Yes, the trailer is parked in a level spot on my driveway, both side to side and front to rear.

5. If you have a Gas Pressure problem(to low), then Gas is not the way to test operation. Without a Manometer, you cannot verify gas pressure. Just 1 inch low will cause cooling problems.
No gas pressure problems that I am aware of, everything else works just fine. I switched the fridge back to "auto" so it's running on AC now.

6. The 120 wired direct is the best way to go for the 24 hour check. IF after 24 hours and the freezer is NOT below 10 degrees and the refer NOT below 38 degrees (AND THE REAR VENTILATION IS NOT RESTRICTED BOTTOM TO TOP BEHIND THE REFER), Then your cooling unit is probably shot.
I'm unable to verify if the vent fan is working or not.

7. LAST, you don't state if the refer is in a slide room. If it is and you do not have the rear cooling fans operating you will have diminished cooling.
It is located in a slide room.

Right now I am unable to verify that the vent fan is running behind the fridge, it's pouring rain here. I have this cordless fan that I placed behind the fridge blowing up on to the cooling unit. Going to let this run for a few hours and see if it drops the temps, if so the fan likely needs replacement. If the fan doesn't bring the temps down, then I likely will need a cooling unit.

[bgum]

I would move your thermistor to the second fin from the right and then slide it to the top. Make sure you a getting good airflow in the back of the unit.

[dougrainer]

1. The Evap fins will be 10 degrees colder than the actual items in the refer. Where did you install the probe for your thermometer you purchased?
2. 120 elements either work or they do NOT work. No in between/partial operation.
3. WAIT 24 hours before getting a reading
4. Have you verified that the unit is level, now, and when you started loading it up for your trip?
5. If you have a Gas Pressure problem(to low), then Gas is not the way to test operation. Without a Manometer, you cannot verify gas pressure. Just 1 inch low will cause cooling problems.
6. The 120 wired direct is the best way to go for the 24 hour check. IF after 24 hours and the freezer is NOT below 10 degrees and the refer NOT below 38 degrees (AND THE REAR VENTILATION IS NOT RESTRICTED BOTTOM TO TOP BEHIND THE REFER), Then your cooling unit is probably shot.
7. LAST, you don't state if the refer is in a slide room. If it is and you do not have the rear cooling fans operating you will have diminished cooling. Doug

[2oldman]

BurbMan wrote:
I appreciate the help guys! Yes an IR thermometer is not the most accurate but was enough to confirm I have a problem. .

I don't know what accuracy these folks are expecting.

Did you pull the back and check for leakage in the coils?

[ferndaleflyer]

I had that same problem once and Doug walked me through it...never replaced the cooling unit and everything has worked ever since....I may have reprogrammed it!

[BurbMan]

I appreciate the help guys! Yes an IR thermometer is not the most accurate but was enough to confirm I have a problem. I installed the AccuRite wireless fridge and freezer thermometer and it's confirming my readings. Amazon same-day delivery is a great innovation, but save that for another post. Ordered at 10 am and was delivered by 1:30pm.

I set the fridge to "GAS" and dialed the temp control up to "5".


I double checked the thermistor, and this is as far as it will go up on the fin:


Here's the readings I'm getting on the Accurate sensors after being installed for about an hour. These were close to the same readings I was getting with the IR thermometer (the -15 must have been wrong, Doug).


So it looks like the cooling unit is bad? I thought switching over to gas would rule out a weak heating element but that doesn't appear to be the problem.

[Grit_dog]

Let’s try to stay on task kids. Stop arguing about thermometers. Pretty sure OP could tell his fridge was way to warm

[dougrainer]

Joe417 wrote:
The thermistor won't cause that much difference in temp. I had the same issue with our Norcold. Freezer worked but fridge didn't. I had to replace the cooling unit last fall.

The test to prove cooling unit operation, disconnect the AC heating element from the control board and connect the AC heating element directly to AC power and allow it to run overnight. Next morning, it should be below freezing in both the fridge and freezer.

I replaced ours with a Dutch Aire and it seems to be a more efficient unit than the Norcold.

Like you, we discovered our fridge problem as we got ready to take a trip. Fortunately, we have a 12V chest cooler and it didn't stop our trip.

Good Luck

Joel, An IR thermometer is NEVER used for refer and AC cooling temp measurements. The ONLY accurate temp measurement is a small glass of water left inside the refer for 24 hours and then taken with a metal probe type thermometer. You can argue all you want but you are plain wrong. Your testing procedure is spot on and that is what is needed for this OP's testing.

[Joe417]

The thermistor won't cause that much difference in temp. I had the same issue with our Norcold. Freezer worked but fridge didn't. I had to replace the cooling unit last fall.

The test to prove cooling unit operation, disconnect the AC heating element from the control board and connect the AC heating element directly to AC power and allow it to run overnight. Next morning, it should be below freezing in both the fridge and freezer.

I replaced ours with a Dutch Aire and it seems to be a more efficient unit than the Norcold.

Like you, we discovered our fridge problem as we got ready to take a trip. Fortunately, we have a 12V chest cooler and it didn't stop our trip.

Good Luck

[BurbMan]

I did use an IR thermometer

[dougrainer]

1. What KIND of digital thermometer? Did you place the Thermometer in a glass of water that had been in the refer 24 hours without opening the doors? There is NO WAY your freezer read -15 degrees. That -15 is interpreted as BELOW 0 degrees by 15 degrees. Or do you mean the temp was 15 degrees?
2. I hope you did not use a IR thermometer. These will not give correct accurate temps for refer readings
3. There is NO temp adjustment on RV refers for the freezer. The Temp system only adjusts the lower refer section and since you have an adjustable temp setting do not worry about the slider on the fins. Moving the slider is an option for Auto temp refers that have NO adjustable tstat. And that only changes the set temp by about 4 degrees.
4. Your normal temps shopuld be 0 to 10 degrees in the freezer and 28 to 36 in the refer.
5. Is it possible you were not completely level when loading up? That would degrade the ability to cool correctly. Doug

[pianotuna]

Unfortunately, there may be a blocked tube.

[bgum]

You should have some play in the cord. Try pulling it out some. I use a clothes pin to keep ours at the top of the fin.