Norcold 842-IM Cooling Needs to Be Set Higher Than Normal

I have the Norcold 842-IM Refrigerator in my coach. When I bought it 3 years ago, the refer operated perfectly when set on 5.  But for the past two seasons I have had to set it on 8 (with 9 being the highest setting) in order to maintain proper temps.  I seem to recall reading somewhere that the placement of the sensor clip on the fin inside the cooling compartment affected the setting.  This summer I checked mine and it appeared to be a bit rusty so I removed it from that fin and after cleaning up the clip as best I could put it on another fin that did not have any markings but I am not sure the clip itself is completely free.

Question:  I have checked all of the other possibilities behind the unit and the roof exhaust and see no problem.  Is is possible that the clip connection to the fin is the problem and that I should just try to replace the clip?  I also read that by moving the clip up or down the fin, the temp can also be affected.  Not sure about that one though.  I have the owners manual and it is pretty detailed but I can find no mention of the clip to the cooling fins or anything about moving it up and down to adjust cooling.  Advice please.

Bill

The clip is called the thermistor and by raising it up cooling might improve. Also I bought some 2? pvc couplers and put a couple on each shelf for better ventilation

Bill N said:

but I am not sure the clip itself is completely free.

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Bill what do you mean by "completely free"?
Yes moving it up or down does change things but I'm not sure which way. Can you see where the clip was originally?  If you can, put it back there and see what happens.

Lucky Lou said:

The clip is called the thermistor and by raising it up cooling might improve. Also I bought some 2? pvc couplers and put a couple on each shelf for better ventilation

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1st, welcome to the forum. Can you explain what are 2" pvc couplers and how do they improve circulation by placing them on a shelf?
Is this what you're referring to?

https://www.homedepot.com/p/Charlotte-Pipe-2-in-PVC-Sch-40-S-x-S-Coupling-PVC021001600HD/203811391

I have no idea what the couplers are and my post was so long ago that I am trying to remember why I said completely free.  Darned old age is showing. Anyway, I read somewhere else that if you put a small piece of one of those foam coffee cups between the fin and the thermister (place it inside the thermister clip) it would make the fridge work harder to get the thermister cool and solve the problem.  Haven't tried that yet but it would seem to work the opposite - by making the cooling unit work harder you would need to jack up the setting and since I am already on 8 that may not be the answer for me.

Bill N said:

Anyway, I read somewhere else that if you put a small piece of one of those foam coffee cups between the fin and the thermister (place it inside the thermister clip) it would make the fridge work harder to get the thermister cool and solve the problem.  Haven't tried that yet but it would seem to work the opposite - by making the cooling unit work harder you would need to jack up the setting and since I am already on 8 that may not be the answer for me.

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While I'm not sure if the little trick would work.....I don't think it going to make the reefer work "Harder"....Just run longer until it senses the set temperature.

Put the thermistor back on the fin it was originally on.  It was calculated and designed to be on that fin.  By moving it closer to the middle of the heat exchanger you made a change in the wrong direction.

Moving the thermistor UP on that fin will lower the temperature of the refrigerator.  I don’t know about your refer but mine works best on setting 3 or 4.  Anything higher seems to make it warmer.

As the ‘inventor’ of the Muddypaws Mod I have seen many refrigerators work better with the coffee cup foam between the thermistor and the fin.  If you search for ‘Muddypaws Mod’ on this forum you’ll find detailed instructions.  It’s free.

8Muddypaws said:

Put the thermistor back on the fin it was originally on.  It was calculated and designed to be on that fin.  By moving it closer to the middle of the heat exchanger you made a change in the wrong direction.

Moving the thermistor UP on that fin will lower the temperature of the refrigerator.  I don?t know about your refer but mine works best on setting 3 or 4.  Anything higher seems to make it warmer.

As the ?inventor? of the Muddypaws Mod I have seen many refrigerators work better with the coffee cup foam between the thermistor and the fin.  If you search for ?Muddypaws Mod? on this forum you?ll find detailed instructions.  It?s free.

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Thanks.  I will give that a try when the coach comes out this spring.  I think there was also a spot of rust or corrosion on the thermistor too but not on the aluminum fin.  I tried to clean most of it off before moving it around but I can't see where I will lose anything trying your Muddypaws Mod.  Now to find a foam coffee cup....LOL

Bill N said:

I have no idea what the couplers are and my post was so long ago that I am trying to remember why I said completely free.

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For some of us, yesterday was long ago.  ??? : :-[ :-\ :'(