Good Sam Club Open Roads Forum: Moving fridge thermistor up = warmer??
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Moving fridge thermistor up = warmer??

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Next
wopachop

Who run bartertown

Senior Member

Joined: 11/17/2006

View Profile


Offline
Posted: 06/21/20 06:54pm Link  |  Quote  |  Print  |  Notify Moderator

Came across this link where the guy explains how moving the thermistor higher on the cooling fins actually creates a warmer fridge temperature. Which is the opposite of what the little sticker inside the fridge directs us to do.

If you read the 1 comment there is a reply that explains his reasoning.

Second question if i unplug the thermistor from the back of the fridge will that make it cool 24/7? I accidentally turned my fridge off yesterday and didnt catch it till this morning. Got to 60F in there darn it. Its down to 45F now and leveled off for a couple hours. I pulled the thermistor completely off the fins. Any advice on that topic is appreciated as well.

https://rvrefrigeratorrepair.com/uncateg........icking%E2%80%9D%20the%20control%20board.

DrewE

Vermont

Senior Member

Joined: 08/23/2014

View Profile


Offline
Posted: 06/21/20 07:12pm Link  |  Quote  |  Print  |  Notify Moderator

I'd trust the sticker put there by the makers of the fridge over the opinion of some random guy (or gal) making a web page somewhere on the internet as to which direction to move the thermistor to achieve some particular end. For that matter, I'd trust the fridge maker's directions over anything suggested by a random poster possibly called DrewE on some RV related web forum, too, all other things being equal.





dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 06/21/20 07:18pm Link  |  Quote  |  Print  |  Notify Moderator

Moving the Thermister is for AUTO temp refers that have no adjustable tstat. That is why the OEM(refer maker) installs that sticker. If you have an adjustable tstat on the control panel moving does nothing. As the link stated, you only get about 4 to 5 degrees colder difference. Doug

wopachop

Who run bartertown

Senior Member

Joined: 11/17/2006

View Profile


Offline
Posted: 06/21/20 09:12pm Link  |  Quote  |  Print  |  Notify Moderator

Now if I pull the thermistor completely off the cooling fins, shouldnt I see fridge temp get very low before it cycles off and allows temps to rise?

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 06/22/20 09:31am Link  |  Quote  |  Print  |  Notify Moderator

wopachop wrote:

Now if I pull the thermistor completely off the cooling fins, shouldnt I see fridge temp get very low before it cycles off and allows temps to rise?


Possibly, Some Control boards react differently. There is a resistance/Ohm signal from the Thermister and if out of normal range may cause malfunction of the Cooling cycle. On Norcolds, if you disconnect(unplug) the Thermister, it will cause a BOS cooling cycle. This causes the refer to alternate between cooling and shutting off at timed intervals. But, for a lot letting it hang down will cause 24/7 operation, until the refer Thermister gets cold enough if that is possible. Remember, The Thermister senses the FIN temp, not the air temp. The fin temp will be 10 degrees colder than the actual refer temp. No harm in trying, post what happens. Doug

30sweeds

Iowa

New Member

Joined: 03/24/2018

View Profile


Offline
Posted: 06/23/20 07:46am Link  |  Quote  |  Print  |  Notify Moderator

Mine was inadvertently pulled off the fin and was hanging loose inside the unit.Temp went from 38 to mid 50's and probably still climbing.Reattached,back to 38....top of fin.

wa8yxm

Wherever I happen to park

Senior Member

Joined: 07/04/2006

View Profile


Offline
Posted: 06/23/20 04:07pm Link  |  Quote  |  Print  |  Notify Moderator

I have read many posts and even watched a few Videos from people who seriously gotten it wrong.. In fact I've had to apologize for getting it bass ackwards a few times myself.
(The difference between me and many is that apology) IN fact I think I'm about to type one elsewhere.

The it is not that heat rises but that all other factors being the same warmer air is LESS DENSE thus it rises to the top of the chamber.. So the warmest air is at the top of the chamber

Since the thermistor on the fins is measureing the air temp. the higher it is the hotter it is.. (ok so perhaps 1 degree hotter at most) so since it will report a higher temp to the control board the controller will try to make things COLDER.

This may confuse some.


Home is where I park it.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times


wopachop

Who run bartertown

Senior Member

Joined: 11/17/2006

View Profile


Offline
Posted: 06/23/20 07:24pm Link  |  Quote  |  Print  |  Notify Moderator

wa8yxm wrote:

I have read many posts and even watched a few Videos from people who seriously gotten it wrong..
You are still getting it wrong. At least there is consistency!!

DrewE

Vermont

Senior Member

Joined: 08/23/2014

View Profile


Offline
Posted: 06/23/20 07:30pm Link  |  Quote  |  Print  |  Notify Moderator

wa8yxm wrote:


Since the thermistor on the fins is measureing the air temp. the higher it is the hotter it is.. (ok so perhaps 1 degree hotter at most) so since it will report a higher temp to the control board the controller will try to make things COLDER.

This may confuse some.


The thermistor is mainly measuring the temperature of the fin, and not of the air. If it were sensing the air, then the fridge would not behave much differently if the thermistor were removed from the fin and placed elsewhere in the compartment, but that does indeed happen. (Indeed, if they were interested in measuring the air temperature in the fridge, it would make far more sense to not mount it on the cooling fin at all, but rather someplace more representative of the air temperature.)

The fin temperature varies a little from top to bottom since the coolant flows downwards through the system at that point in the refrigeration cycle.

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 06/24/20 10:05am Link  |  Quote  |  Print  |  Notify Moderator

wa8yxm wrote:

I have read many posts and even watched a few Videos from people who seriously gotten it wrong.. In fact I've had to apologize for getting it bass ackwards a few times myself.
(The difference between me and many is that apology) IN fact I think I'm about to type one elsewhere.

The it is not that heat rises but that all other factors being the same warmer air is LESS DENSE thus it rises to the top of the chamber.. So the warmest air is at the top of the chamber

Since the thermistor on the fins is measureing the air temp. the higher it is the hotter it is.. (ok so perhaps 1 degree hotter at most) so since it will report a higher temp to the control board the controller will try to make things COLDER.

This may confuse some.


Trust me, YOU do a good job of confusing people with your lack of knowledge[emoticon]

PS, The Thermister senses the Temp of the metal evap fin. AND you did not have to watch a Video to learn this

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Next

Open Roads Forum  >  Tech Issues

 > Moving fridge thermistor up = warmer??
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.