Fridge not cooling properly, Freezer normal

docwade87 · 09-05-2020, 05:58 PM

My fridge won’t get much colder than 40 anymore. The freezer is keeping things at 0 degrees as it should. What am I missing? The temps aren’t an issue and haven’t been in past. It’s actually much cooler today (70s) and the fridge still won’t cool past 40. Have checked thermostat inside and made sure it was adjusted in fins properly and it is. No dust around flue or anything out of the normal from the outside side vent. Heading for week long trip Monday. Any help appreciated. If anything I’ll keep meats in cooler so they don’t spoil and get fridge serviced once I get back.

Mwoods321 · 09-08-2020, 09:31 PM

I'm having same issue. I've read could be a circuit board, could be a heating element, etc. All look easy to replace, but how do you know which part needs replacing. Would love to hear if you find an answer.

Customer1 · 09-09-2020, 05:11 PM

The most common refrigerator problem is poor installation. Read the installation manual and then examine your refrigerator installation. The clearances are critical.

Pull Toy · 09-10-2020, 05:30 AM

If the freezer is working, but the fridge won't cool, check your owners manual for troubleshooting tips. If it did work, but now doesn't it's probably something minor, and probably not an installation issue, in my opinion.

I haven't had problems in several years, but if it is an RV type, as opposed to residential, you will probably find a temp sensor clipped to the cooling fins at the rear wall of the refrigerator section. By sliding this up or down, you should be able to solve your issue. In one instance many years ago, I accidentally un-clipped it completely while cleaning. You may have knocked it out of position too.

This would be my first attempt at a fix, before I spent any money on parts.

Good Luck,

docwade87 · 09-10-2020, 06:12 AM

The sensor in the fins is and has been in correct position for over a year. Even verify it’s where it should be every trip. I’ve looked at manual and there are no “trouble shooting tips.” Only tips is to contact a trained professional to service unit if there are issues. It stays cold (42) but not as cold as a refer should.

MarkEHansen · 09-15-2020, 07:11 AM

You say the sensor is in the correct position, but it's a sliding position - allowing you to adjust the temperature. There should be a sticker which shows that when you slide it one way (I think lower) the temp gets warmer and sliding the other way, the temp gets colder.

Did you try sliding it further in the cold direction?

**JRTJH** · 09-15-2020, 07:42 AM

Quote:

Originally Posted by docwade87

The sensor in the fins is and has been in correct position for over a year. Even verify it’s where it should be every trip. I’ve looked at manual and there are no “trouble shooting tips.” Only tips is to contact a trained professional to service unit if there are issues. It stays cold (42) but not as cold as a refer should.

It's not clear which refrigerator brand or model you have, but both Norcold and Dometic use the thermistor technology to control refrigerator temperature. There is "limited to no troubleshooting advice" in the owner's manual... In the service manual for both, there is a bit more troubleshooting information, but even that manual doesn't fully address the "refrigerator is too warm" condition...

The thermistor "recommended location is on the far right side of the cooling fins and it is moved up or down to adjust (or fine tune) the "lower box" temperature. Occasionally there's a refrigerator that doesn't respond correctly for some "known or unknown reason"... One step that is not clear in either manual is that you can "move the thermistor to the left a fin or two" and often improve temperature regulation...

Have you physically checked that the thermistor is in the correct position in the holder? It should be "centered vertically in the bracket" and the bracket should be centered on the far right fin. THIS IS ONLY A STARTING POINT FOR TEMPERATURE ADJUSTMENT

Once that is confirmed, try the refrigerator. If it's too cool, adjust the bracket down slightly on the fin. If it's too warm, slide the bracket up slightly on the fin.

HERE'S THE IMPORTANT PART: If the refrigerator can not be adjusted to a suitable temperature with the bracket on the far right fin, then move the entire bracket/thermistor to the left ONE FIN and try again....

Just as there are some shoes that the correct size fits every foot, there is an occasional foot that won't fit the "standard size".... Your refrigerator may be one that needs "a bit more fine tuning" than most....

Keep moving your bracket/thermistor up and down and one fin to the left until you get the desired result.... For many (not all) refrigerators, there's a "sweet spot" for the thermistor location....

BUT FIRST: BE SURE THE THERMISTOR IS CENTERED IN THE BRACKET. IF IT'S TOO HIGH OR TOO LOW IN THE BRACKET, THEN THE BRACKET PLACEMENT WILL BE INCORRECT CAUSING YOU TO THINK THE REFRIGERATOR IS NOT WORKING PROPERLY......

wiredgeorge · 09-15-2020, 08:05 AM

I am not sure I understand this thread. Fella said his refrigerator was 40F. That is the optimal temp as far as I know. He could slide his thermistor a bit as suggested to get the fridge temp to come down a degree or two but sounds to me it is working as it should.

docwade87 · 09-15-2020, 08:18 AM

Quote:

Originally Posted by JRTJH

It's not clear which refrigerator brand or model you have, but both Norcold and Dometic use the thermistor technology to control refrigerator temperature. There is "limited to no troubleshooting advice" in the owner's manual... In the service manual for both, there is a bit more troubleshooting information, but even that manual doesn't fully address the "refrigerator is too warm" condition...

The thermistor "recommended location is on the far right side of the cooling fins and it is moved up or down to adjust (or fine tune) the "lower box" temperature. Occasionally there's a refrigerator that doesn't respond correctly for some "known or unknown reason"... One step that is not clear in either manual is that you can "move the thermistor to the left a fin or two" and often improve temperature regulation...

Have you physically checked that the thermistor is in the correct position in the holder? It should be "centered vertically in the bracket" and the bracket should be centered on the far right fin. THIS IS ONLY A STARTING POINT FOR TEMPERATURE ADJUSTMENT

Once that is confirmed, try the refrigerator. If it's too cool, adjust the bracket down slightly on the fin. If it's too warm, slide the bracket up slightly on the fin.

HERE'S THE IMPORTANT PART: If the refrigerator can not be adjusted to a suitable temperature with the bracket on the far right fin, then move the entire bracket/thermistor to the left ONE FIN and try again....

Just as there are some shoes that the correct size fits every foot, there is an occasional foot that won't fit the "standard size".... Your refrigerator may be one that needs "a bit more fine tuning" than most....

Keep moving your bracket/thermistor up and down and one fin to the left until you get the desired result.... For many (not all) refrigerators, there's a "sweet spot" for the thermistor location....

BUT FIRST: BE SURE THE THERMISTOR IS CENTERED IN THE BRACKET. IF IT'S TOO HIGH OR TOO LOW IN THE BRACKET, THEN THE BRACKET PLACEMENT WILL BE INCORRECT CAUSING YOU TO THINK THE REFRIGERATOR IS NOT WORKING PROPERLY......

It is a dometic.

The thermistor is on the far right fin and has been. I have even adjusted the thermistor inside the bracket to be a the top of the bracket and even top of the range as shown on the reference guide to the right on the wall of the fridge to achieve better cooler temps, with no luck. The fridge used to hold at 36-38 no issue at all times even during the heat of the summer. Now I can’t get it below 42-44. Meats are spoiling within a couple day’s. I have adjusted the actual thermistor itself up and down. Yes it’s highest point is supposed to be coldest and obviously I don’t put it on the lower end. I used to keep it at 3/4 to the top to receive optimal temp. Now at the top setting, it won’t go below 42 and takes quite some time to cool past 45 once the fridge is opened and accessed to get food or beverage.

I’ll have to look again but if I remember correctly, the bracket will not fit on any of the fins that are in between the far right or left fins.

**JRTJH** · 09-15-2020, 08:29 AM

You may have a faulty thermistor ???? Or a faulty control board ???

You can buy either online. There also is a thermistor repair kit available from Dometic. Here are the instructions on how to repair/replace the thermistor system without removing the refrigerator from the RV: http://techsupport.pdxrvwholesale.co...307873.004.pdf

Javi · 09-15-2020, 08:52 AM

Quote:

Originally Posted by docwade87

It is a dometic.

The thermistor is on the far right fin and has been. I have even adjusted the thermistor inside the bracket to be a the top of the bracket and even top of the range as shown on the reference guide to the right on the wall of the fridge to achieve better cooler temps, with no luck. The fridge used to hold at 36-38 no issue at all times even during the heat of the summer. Now I can’t get it below 42-44. Meats are spoiling within a couple day’s. I have adjusted the actual thermistor itself up and down. Yes it’s highest point is supposed to be coldest and obviously I don’t put it on the lower end. I used to keep it at 3/4 to the top to receive optimal temp. Now at the top setting, it won’t go below 42 and takes quite some time to cool past 45 once the fridge is opened and accessed to get food or beverage.

I’ll have to look again but if I remember correctly, the bracket will not fit on any of the fins that are in between the far right or left fins.

I didn't read the entire thread...and probably won't

But I got a question.... Is this fridge in a slide? and if so.. are the cooling fans still working? OH, and did you by any chance find a piece of Luan in the top vent?

**flybouy** · 09-15-2020, 08:55 AM

Correct fridge Temps can be found here......
https://www.homebrewersassociation.o...ighter%20beers.

docwade87 · 09-15-2020, 09:11 AM

Quote:

Originally Posted by JRTJH

You may have a faulty thermistor ???? Or a faulty control board ???

You can buy either online. There also is a thermistor repair kit available from Dometic. Here are the instructions on how to repair/replace the thermistor system without removing the refrigerator from the RV: http://techsupport.pdxrvwholesale.co...307873.004.pdf

That’s what I’m hoping. Thanks for the help. Will start with this.

ChuckS · 09-16-2020, 04:53 AM

Disconnect thermistor and measure resistance of it compared to ambient temps..ohm reading will have a corresponding value to the temp...if not close to readings specified.. And you will find this in the Dometic service manual then leave thermistor disconnected for 24 hours...if fridge temp now good thermistor is bad...

Also check the condenser thru vent on upper level vent and make sure it’s clean.. if there is a baffle in place leave it in place...it’s there for a reason...baffle will be a piece of paneling, etc covering about 1/2 the condenser surface area...

wiredgeorge · 09-16-2020, 06:36 AM

Quote:

Originally Posted by ChuckS

Disconnect thermistor and measure resistance of it compared to ambient temps..ohm reading will have a corresponding value to the temp...if not close to readings specified.. And you will find this in the Dometic service manual then leave thermistor disconnected for 24 hours...if fridge temp now good thermistor is bad...

Also check the condenser thru vent on upper level vent and make sure it’s clean.. if there is a baffle in place leave it in place...it’s there for a reason...baffle will be a piece of paneling, etc covering about 1/2 the condenser surface area...

Chuck, Explain measuring the resistance compared to ambient temps. You measure the resistance of the thermistor in place in the fridge and removed when it is out of the fridge? What is a corresponding value to the temp mean? I understand resistance and how to use a multimeter and a good explanation would sure help me understand. TIA.

ChuckS · 09-16-2020, 07:12 PM

Measuring ambient temp with thermistor removed and reading corresponding ohms reading at ambient temp is just as good as measuring it in the fridge. It would give a relative point. You could then place in a Temp Meausured glass of cold water and again read the ohms of thermistor and compare to chart...

If you don’t know how cold the fridge is or isn’t then using that as your temp reference point is rather mute..

https://www.arprv.com/dometic-thermistor.php

Quickest way is to disconnect the thermistor and of fridge gets cold then you know thermistor is bad....

Everyone has their own way of testing ...
Mine was stated and will work

**JRTJH** · 09-16-2020, 07:58 PM

I haven't thought about it in probably 5 years or more and haven't "dug in the books to confirm what I think I remember", but disconnecting the thermistor at the control board "simulates an open thermistor" and puts the control board/refrigerator in "limp mode" which is "max cooling"... As Chuck said, disconnect the thermistor at the control board, if the refrigerator is cold in the morning, it's a bad thermistor... If the refrigerator is not cold, it could be the control board, a defective thermistor (not providing proper resistance to the control board) or a cooling unit/burner assembly issue.

I'd suggest foregoing the resistance checks and "cut to the chase" by disconnecting the thermistor at the control board and seeing what happens 12 hours later.....

wiredgeorge · 09-17-2020, 03:05 AM

Makes more sense now. You guys should do a youtube video as I have never heard about checking a thermistor in this way. First camper I ever owned had the thermistor unconnected to a cooling fin and dangling and i had no idea what it was.

xrated · 09-17-2020, 04:37 AM

A VERY important factor, as someone mentioned briefly, is the cooling fans on the rear of the fridge. I'm not familiar with the Dometic, but the Norcold that I have in my trailer actually has three fans in the rear.....one pretty small one and two larger fans. The Norcold fridge issues with not cooling properly are many, one of which is adding additional fans in the rear to help move more air over the heat exchanger. Check the fans in the rear (however many are back there on your model) and make SURE that they are running when the fridge is running. If they aren't, there is obviously an issue either with the fans or the controller that turns them on. I ended up adding two more fans on the upper vent, blowing outward, to help move more air across the heat exchanger and it made a world of difference on how the unit cools. BTW, all of my fans WERE running when they were suppose to be, but they simply were not moving enough air on the hot days. Good luck.

Javi · 09-17-2020, 04:42 AM

Quote:

Originally Posted by xrated

A VERY important factor, as someone mentioned briefly, is the cooling fans on the rear of the fridge. I'm not familiar with the Dometic, but the Norcold that I have in my trailer actually has three fans in the rear.....one pretty small one and two larger fans. The Norcold fridge issues with not cooling properly are many, one of which is adding additional fans in the rear to help move more air over the heat exchanger. Check the fans in the rear (however many are back there on your model) and make SURE that they are running when the fridge is running. If they aren't, there is obviously an issue either with the fans or the controller that turns them on. I ended up adding two more fans on the upper vent, blowing outward, to help move more air across the heat exchanger and it made a world of difference on how the unit cools. BTW, all of my fans WERE running when they were suppose to be, but they simply were not moving enough air on the hot days. Good luck.

YEP... I've seen several folks at the local COE campground who are complaining about the fridge not being cool enough and when you start asking questions.. the first thing they admit to is taking that piece of plywood out of the vent.. or disconnecting the fan because it made too much noise..

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