Refrigerator Not As Cold As It Ought To Be

[buylow12]

Hello everyone, back again after a while(Believe it or not I've been able to fix some stuff on my own 😉 Anyways my Domestic Americana is not cooling as well as it should, particularly the fridge. The freezer is still keeping things frozen but my ice cream is soft, always a sign it's not as cool as it should be. However the refrigerator is only mildly cool and I'm going to have so food going bad if I can't figure this out. I switched it over to propane as I usually find that works better but it didn't make much difference. I also just removed both exterior vents and everything looks clear.

When I took them off though it occurred to me that I haven't heard the fan run in a while. Usually when it's hot out I can hear the little buzz of it running and I can't remember the last time I heard it. Is there a way to confirm the fan isn't working? Any particular fan I should replace it with? Is the fan being broken enough to cause this? I read the fan can increases efficiency by 40% somewhere so if that's true I'd think it could. Will leaving the vents off in the meantime help?

Well thanks as always for all the help and if you have anything else you think it could be or anything I should check please fire away 😉

[BJean]

Thanks for all info. My factory fan and switch were working but as I have
the ref in slide it was not able to cool properly. Added new fan and switch
at top vent and freezer is now 0 or below. Will add a 12V fan to inside to
keep ref temp steady.

[Larryect]

dougrainer wrote:


I guess I did not explain it correctly. The FREEZER has NO way to control its temp. It will get to 0 to 10 degrees regardless of the Temp set. The design of an RV absorbsion refer is such that the Freezer coils are the FIRST coldest section of the tubes. Then it goes down to the lower refer section. This lower section is what is controlled by the tstat. Both Dometic and Norcold operate the exact same way. This is what confuses novices. They buy a used RV and the seller shows how COLD the freezer is and they assume the refer is at operating spec. They go home and then find that the lower section does NOT get below 40 degrees because the refer is partially blocked. A defective/blocked refer will still get the freezer below 10 degrees because the blockage is past the freezer coils. If you are having a problem with getting the freezer below 10 degrees, then you either have a incorrectly sealed cooling unit to the box or there is a lack of the correct amount of Transfer Mastic on the freezer coils. That is why I asked if the Cooling unit had ever been replaced. Long shot would be a defective freezer door seal, but those are rare. Doug

I have a Norcold N811 which is about 3 years old, never rebuilt. Mounted in the slide. Currently 100 degrees outside 80 inside.

The freezer is at 6 degrees and the fridge is running 43. Temp selector is at 5. Sounds like fans are running. Have not visually confirmed. Added a small 110 desk fan blowing up inside the back of the unit - don't think it is helping. Last night the fridge got down to 31 but not the really doing well when 95+ outside.

Any suggestions?

Edit to add: I have a small internal fan (e-bay) blowing over the coils at the thermistor.

[pnichols]

marcsbigfoot20b27 wrote:
In short you cant change the delta of the fridge and freezer.
Well, not in terms of setpoints anyhow. You may be able to change it by using an internal fridge fan increasing efficiency, but the fridge temp thermister and control board cycles the whole unit on and off.

When on, your freezer gets full "Coldness" or heat absorption for lack of better explanation, what is left goes to the fridge compartment. Working as designed you probably see a 30-35 delta so 0 freezer and 30-35 in the fridge on a good working unit. If you want it colder you can fool the thermister by thinking it is warmer, (I have a Dometic adjustable thermister box) and the cooling unit AC or propane will stay on longer. Then the freezer will get a few degrees colder and so will the fridge, mostly at the same delta.
The experts can chime in if Im wrong.

Note, mine is a Dometic Americana Rm2652 that is not "adjustable" there is no numbers to select, just the fin thermister.

Thanks for your excellent clear and detailed explanation!

Using the highest setting on our refrigerator ("5"), our freezer section is around 0 degrees and the refrigerator section is indeed 30-35 degrees ... so it looks like our Norcold is working as it should. Using a setting of "5", I wish I could raise the refrigerator section's temperature a bit so, for example, milk doesn't freeze with the freezer section still kept around 0 degrees at a setting of "5".

[marcsbigfoot20b]

pnichols wrote:
I know what the temp control does.

Some (many in the forums) say that sliding the thermistor up or down on the fin does something. Some say it doesn't. Neither have explained the why of their position ... they just want us to take them at their word or spend the time to run our own experiments.

I prefer to do neither without an explanation of the why of what's going with sliding of the thermistor.

What myself and many other RV propane refrigerator owners would like to know is: Can I use the temperature control to adjust the freezer temperature to what we want and then use the thermistor to then adjust the refrigeration section to the be as close as possible to the temperature that we want. It doesn't take a rocket science answer.

In short you cant change the delta of the fridge and freezer.
Well, not in terms of setpoints anyhow. You may be able to change it by using an internal fridge fan increasing efficiency, but the fridge temp thermister and control board cycles the whole unit on and off.

When on, your freezer gets full "Coldness" or heat absorption for lack of better explanation, what is left goes to the fridge compartment. Working as designed you probably see a 30-35 delta so 0 freezer and 30-35 in the fridge on a good working unit. If you want it colder you can fool the thermister by thinking it is warmer, (I have a Dometic adjustable thermister box) and the cooling unit AC or propane will stay on longer. Then the freezer will get a few degrees colder and so will the fridge, mostly at the same delta.
The experts can chime in if Im wrong.

Note, mine is a Dometic Americana Rm2652 that is not "adjustable" there is no numbers to select, just the fin thermister.

[pnichols]

I know what the temp control does.

Some (many in the forums) say that sliding the thermistor up or down on the fin does something. Some say it doesn't. Neither have explained the why of their position ... they just want us to take them at their word or spend the time to run our own experiments.

I prefer to do neither without an explanation of the why of what's going with sliding of the thermistor.

What myself and many other RV propane refrigerator owners would like to know is: Can I use the temperature control to adjust the freezer temperature to what we want and then use the thermistor to then adjust the refrigeration section to the be as close as possible to the temperature that we want. It doesn't require a rocket science answer.

[SidecarFlip]

The Thermister controls the cycling of the control board which controls the propane delivery or the heating element(s). The temp control set the control board parameters to run longer, thus getting colder.

I think Doug is tired of your abstinence. Told you do. If, in fact you heed his advice is up to you....

[pnichols]

Well Doug ... you never did explain in detail what the thermistor controls and how that control is affected by it being lower or higher on the cooling fin. You also never acknowledged whether or not the temperature control switch merely sets the cooling unit's ON/OFF duty cycle.

Maybe that's why you felt that your responses were not getting anywhere.

[dougrainer]

pnichols wrote:
Doug,

Here's a cut-and-paste quote from Page 6 of the owners manual of our Norcold Model 611 2-Way propane RV refrigerator:

"The temperature switch (2) controls the temperature adjustment
of the freezer and the fresh food compartment."

This tells me that low numbers of the 5-position temperature switch mean average warmer temperatures for both sections of the unit and high numbers of the 5-position temperature switch mean average lower temperatures for both sections.

Then ... what does sliding of the thermistor do ... over-ride the switch settings, OR MORE LIKELY, change the refrigerator compartment temperature in relation to the freezer compartment temperature?

Thanks I appreciate this:B 38 years and still an RV tech, and both Dometic and Norcold factory training and I have to be schooled by an RV'er:h I wonder, If you move your HOUSE(residential home) Wall Tstat UP 2 feet or DOWN 2 feet, will the house get warmer or colder, regardless of what you set the Tstat at????????? Just wondering,I KNOW the answer:) NO CHANGE that you could measure. I am done with this thread. You can do and believe what you want. Your mind is made up. AWW, the wonders of the Internet. Cheers, Doug

[pnichols]

Doug,

Here's a cut-and-paste quote from Page 6 of the owners manual of our Norcold Model 611 2-Way propane RV refrigerator:

"The temperature switch (2) controls the temperature adjustment
of the freezer and the fresh food compartment."

This tells me that low numbers of the 5-position temperature switch mean average warmer temperatures for both sections of the unit and high numbers of the 5-position temperature switch mean average lower temperatures for both sections.

Then ... what does sliding of the thermistor do ... over-ride the switch settings, OR MORE LIKELY, change the refrigerator compartment temperature in relation to the freezer compartment temperature?

[pnichols]

buylow12 wrote:
If it was blocked though wouldn't the refrigerator be warmer not cooler?

I don't know anything about how your Norco works but generally you slide the thermistor up for colder and down for warmer. Just slide it down and see what happens. I mean what's the worst that can happen? That it does nothing?

Thanks!

From what I have read in these forums over the years concerning RV propane refrigerators, we are one of the fortunate ones to have an excellent refrigerator so far. I has always served us well in high or low outside temps and when partially full or full. I just want to tweak it for better balance between the temperatures in both sections. As I said earlier I haven't called Norcold yet but from what you say above, probably just sliding it's thermistor down a bit on the fin will give me a refrigerator section averaging close to 38 degrees while at the same time a freezer section averaging close to 0 degrees if use a temperature switch position of 4 or 5.

[buylow12]

If it was blocked though wouldn't the refrigerator be warmer not cooler?

I don't know anything about how your Norco works but generally you slide the thermistor up for colder and down for warmer. Just slide it down and see what happens. I mean what's the worst that can happen? That it does nothing?

[dougrainer]

pnichols wrote:
Doug,

I actually had a test going that I started yesterday and that had slipped my mind when I wrote my response above.

Early yesterday I had turned our RV's refrigerator temperature switch to it's max position 5. Outside temperatures have been in the upper 80's for several days here and today and tomorrow will be in the 90's. Our RV is sitting in the back yard plugged into an external outlet on our house. The refrigerator is on electric - which may make it be a bit less efficient than when on propane.

A couple of hours ago the freezer section read slightly under 0 degrees and the refrigerator section read slightly under 30 degrees. So ... it looks like I was correct in that the 5-postion temperature switch controls the entire unit's ON/OFF duty cycle - thus lowing the temperature in both sections simultaneously as the switch is set higher and higher. This makes sense as to how it should have been designed to operate.

What this means is .... in order to maintain the industry recommended standard for household refrigerators of 0 degrees in the freezer section and 38 degress in the refrigerator section ... I have to increase the temperature difference maintained between the two sections so that with the freezer at around 0 degrees, the refrigerator is raised up to around 38 degrees.

Do I slide the thermocouple UP or DOWN on the cooling fins to increase the refrigerator's temperature in relation to the freezer's temperature?

After I get that delta/difference to be about 38 degrees I can then, based on outside temperatures, tweek things merely by using the 5-position ON/OFF duty cycle switch ... just as I'm guessing that the designers intended. The only thing "wrong" with our propane refrigerator so far was that the factory-set position for the cooling fin thermocouple was not quite correct.

Sorry, but sliding the Thermister up and down has no bearing on the freezer OR the lower section. That is for AUTO temp refers ONLY. The Thermister reacts to the fin temp. The fin temp will be about 10 degrees COLDER than the temp in the refer. Now the ONLY way to test refer temps is by a glass of water, NOT the interior temp of the refer itself. Now, YES, the LONGER the refer runs the COLDER the freezer will get by those few degrees. That is why some models have an ambient temp switch that turns the interior light ON and that small heat keeps the lower section from freezing items. But your basic premise is wrong. The fact is, you might have a partially blocked cooling unit that is working pretty good but has enough of a blockage to prevent the lower section from operating correctly.
LINE 120 voltage can make a difference in optimal operation. WHAT is the 120 voltage in the RV? If less than 110, run the refer on LP. Doug

[pnichols]

Doug,

I actually had a test going that I started yesterday and that had slipped my mind when I wrote my response above.

Early yesterday I had turned our RV's refrigerator temperature switch to it's max position 5. Outside temperatures have been in the upper 80's for several days here and today and tomorrow will be in the 90's. Our RV is sitting in the back yard in the sun plugged into an external outlet on our house. The refrigerator is on electric - which may make it be a bit less efficient than when on propane.

A couple of hours ago the freezer section read slightly under 0 degrees and the refrigerator section read slightly under 30 degrees. So ... it looks like I was correct in that the 5-postion temperature switch controls the entire unit's ON/OFF duty cycle - thus lowing the temperature in both sections simultaneously as the switch is set higher and higher. This makes sense as to how it should have been designed to operate.

What this means is .... in order to maintain the industry recommended standard for household refrigerators of 0 degrees in the freezer section and 38 degress in the refrigerator section ... I have to increase the temperature difference maintained between the two sections so that with the freezer at around 0 degrees, the refrigerator is raised up to around 38 degrees.

Do I slide the thermocouple UP or DOWN on the cooling fins to increase the refrigerator's temperature in relation to the freezer's temperature?

After I get that delta/difference to be about 38 degrees I can then, based on outside temperatures, tweek things merely by using the 5-position ON/OFF duty cycle switch ... just as I'm guessing that the designers intended. The only thing "wrong" with our propane refrigerator so far was that the factory-set position for the cooling fin thermocouple was not quite correct.

P.S. Of course the reason for the "soft ice cream" propane RV refrigerator complaints is that the freezer sections in them are not being kept at an average of 0 degrees or less. My test has proved that, for at least our Norcold model and the way Winnebago installed it, an RV propane freezer is capable of maintaining 0 degrees in it's freezer section.

[buylow12]

Speaking of the light in the refrigerator, mine has never worked. I bought another bulb to see if that was the problem even though it appeared fine. That wasn't it. Any advice to track down what the problem is?