Norcold freezer cold, refrigerator not so much

[BarryLS]

I have a model 9162 Norcold that has been sitting for some time. On AC the freezer is down to 10 degree's F, but the fridge is only 55 or so. The chimney area is clear, I have disconnected the thermistor, the thermostat setting is at the highest, the doors close properly. Today we are experiencing cooler temperatures at about 85-90

The coach is level within 1 degree both directions.

I understand the ammonia absorption cycle. Perhaps, as I have read, the unit works better on propane than electric when we have high temperatures. OTOH, I am not understanding the freezer working quite well while the refrigerator poorly.

Anyone have an idea? I've searched without any real success.

My restoration thread:
https://www.winnieowners.com/forums/...on-363346.html

[Morich]

Sounds like you have done the major things to check, so some questions on details may be needed.
One of the big things you mention is that the temp in the freezer is good. So that means the cooling is working, just not getting top and bottom as there is only one system for gas/cooling flow.

Sounds like you may have already looked at the manual but this is the link I looked at for info:
http://techsupport.pdxrvwholesale.co...ser-Manual.pdf

No odd lights and they seem okay?
What about anything blocking cold air from getting down to the lower section?
Not frosted up too much, no covers, etc on the shelves to block air flow?
If I'm not missing something, the cooling is done for the top and the bottom just getsthe cold as the air drops, so look for air flow problems like too much stuff packed near the back?

I'm not seeing any other quick ideas.

EDIT:
A better manual for trouble here:
http://techsupport.pdxrvwholesale.co...rts-Manual.pdf

Possible hint if the colling unit is blocked is on page 30? Doesn't sound right but posssibly something to check?

[BarryLS]

Hi Richard,

That service manual is not one I found, so big thanks for that. I'll read through it and see if it helps.

Lights are normal, I don't have anything in the unit, no frost, door seals check good. From my reading the freezer gets the cooling first, then the fridge. I don't see a way for the freezer air to "drop" to the refrigerator section as there isn't a connection between the two as far as I can see.

It's baffling since it seems to be "working" so well in the freezer.

One thing, no where have I found any indication of what temperatures to expect. I got the freezer to 10 and the refrigerator to about 55 and it held steady at those points this afternoon.

I've turned it off for now. I'll get back to it later, and read the manual you found.

Thanks!

[BarryLS]

I read the service manual which is quite useful for everything but my problem, with the possible exception of the "blocked" problem Richard mentions above. I'll check that tomorrow afternoon or the next day.

I find it rather odd that Norcold doesn't ever state a normal operating temperature, in the owners manual or the service manual. Perhaps on a hot day, on AC, the refrigerator just isn't going to get colder... But it seems like it should at least get to the low 40's.

[dkoldman]

I have seen my Norcold get as cold as -4 in the freezer and 36 in Fridge. It may have been colder but that is what I can recall. I have thermometers in both and how I track when to turn off to conserve batteries or propane if boondocking.

I have at times had water and/or beer starting to freeze in the fridge. I float between 3 , 4 or 5 snowflakes dependent upon outside temp. 5 snowflakes will freeze my beer if is under 80 outside.

Did you say how long you allowed the fridge to cool? My Freezer can get to 32 in 2 hours but may take 6 hours for fridge to get to 48. Otherwise I tend to agree with Morich, you may have some blockage of air flow, or simply missing an issue with the seal.

[BarryLS]

Thanks for the info, dkoldman. Do you know if you get those temps with operation on 110VAC?

The temperatures today were with the unit running over 24 hours, probably near 30 hours. The freezer seems to drop pretty quick but then takes quite a while to get down to the range of 10. It's also hot here, 95 or so yesterday when I started and 85 today. Norcold states that ambient temps above 90 will reduce the cooling, they just don't give any indication of how much (nor do they say what temps you should get).

Airflow is good through the heating area, I've checked it and it's clear. The "blocking" problem mentioned in the manual is an internal blocking issue I believe, perhaps from crystal formation. Anyway, I'll check that and see what I get.

The door seals are good.

I cannot try it with propane since the tank is empty. I have read multiple places (but not from Norcold) that the unit works better/faster with propane operation. Beats me why unless the AC heater is sized such that it doesn't get as hot as the flame.

[dkoldman]

Originally Posted by BarryLS

Thanks for the info, dkoldman. Do you know if you get those temps with operation on 110VAC?

The temperatures today were with the unit running over 24 hours, probably near 30 hours. The freezer seems to drop pretty quick but then takes quite a while to get down to the range of 10. It's also hot here, 95 or so yesterday when I started and 85 today. Norcold states that ambient temps above 90 will reduce the cooling, they just don't give any indication of how much (nor do they say what temps you should get).

Airflow is good through the heating area, I've checked it and it's clear. The "blocking" problem mentioned in the manual is an internal blocking issue I believe, perhaps from crystal formation. Anyway, I'll check that and see what I get.

The door seals are good.

I cannot try it with propane since the tank is empty. I have read multiple places (but not from Norcold) that the unit works better/faster with propane operation. Beats me why unless the AC heater is sized such that it doesn't get as hot as the flame.

I am pretty sure those tests were done at home and on AC. I actually posted pictures with some actual data results. I don't recall if it was thread I created or in response to another thread where the cooling of Norcold was called into question. I was just wanting to see what mine could do because it was always ice cold for us. I bet some searches with words like Norcold, dkoldman, temperatures with attachments may surface it? I may look too, as I will still have the pictures with the exact readings. The pictures show outside temp, inside temp and time of day. They may be on another RV forum?

Outside temperature and humidity will affect the results. Location of fridge and ventilation will also affect results. I have heard of some making some modifications in the rear, but thought that strange to be required. But if you are getting down to 10 in freezer your fridge should at least drop to 40s.

I know you have checked seals, but only time I have seen my fridge warmer than normal was due to the détente on the door not being snapped shut, it was closed. In fact the reason why I bought the temperature gages was to make it easier for my wife to see if door was completely sealed. I think I had 1 or 2 hot beers when I decided that we needed to fix that problem There is alarm on the gauge so it will beep if it gets to warm. The fix is ALWAYS, #1 make sure it has a active power source or #2 shut the door firmly.

UPDATE: I found where I had posted this about a year ago on another forum. At the time, the focus was on how long it took to get cold NOT that it did not get cold enough. I am convinced now that your issues may just be ambient temperatures?

4 Snowflakes is my personal favorite for ice cold beer, here is my setting one morning at 7:40 AM with only 3 Snowflakes. Sensor 2 (top) is Refrigerator and Sensor 1 (bottom) is Freezer. Both sensors are inside the Norcold so door never opened.

FWIW the Freezer hit 27 degrees in 2 hours; while the fridge had barely moved to 71 degrees (Makes sense if you think about how it works)

My unit is 2 years old so maybe they just make them better now, or maybe it will go bad or not cool as good in due time? But for right now, today; I don't get the Norcold as never cool criticism; nor the need to cool down the fridge a full day or two in advance? I think that is myth more so than a need, and/or just a convenience thing for some; but it should NOT be required unless their Norcold is defective? As you can see in 4 hours I was at 3.9 degrees for freezer and 48.7 degrees for fridge with ONLY 3 Snowflakes

[BarryLS]

That is more good information and much appreciated!

I'll run the test on the blocking, but it may just be the ambient temps, especially since it was above 90 the first day, and the inside of the MH is that temperature. I am in the shade at least.

I made sure the door was closed and latched. I do know that with the refrigerator being empty, opening the door causes a big temperature rise, so a door with leaking seals or not latched would certainly be a problem.

Thanks again for the help.

[dajo]

https://www.ebay.com/itm/40372919865...evt=1&mkcid=28 I use well worth the money and you don't have to open the door. Opening the door to check temps will not give good results.
The bottom of my freezer I have seen -3, the top shelf of freezer reads 10 degrees higher than the very bottom. Lower was reading 38. Temp was recorded on the lower shelf, not on the solid bottom shelf. Temps are the same on gas or electric.
All of the cooling for the bottom comes from the large fins in top rear of lower section. I don't see any way the freezer can be cool and the bottom not cool.

[BarryLS]

Thanks dajo, that Accurite is exactly the one I bought. I also bought mechanical gauges as a backup. My reported temps are from the accurite without opening the doors except for when I put the sensors in around noon.

Do you know what the ambient temperature was with your readings?

My refrigerator reading is from the bottom shelf, figuring the lowest point would be coldest.

I'm pretty sure that with ambient I had yesterday afternoon, 10 is the lowest my freezer would do. It had stabilized there and wasn't changing over several hours, and that was with the thermistor disconnected so that it was constantly cooling.

[dajo]

Do you know what the ambient temperature was with your readings?

Used fridge most of the week with temps as high as 95. This is new fridge one month old, Now being checked out by Norcold service center for why on gas burner sputters some of the time. Cooling was still good even with the sputtering.

[Morich]

While it is not important on this problem,some info onthe difference in electric and gas may help some.
I find they both do the same level of cooling but in such different ways that the gas is much quicker.
Thinking of gas, we know it gets hot almost immediately when we start a fire! But if we think of something electric for heat like a room heater or even an iron, we know it takes much longer to heat up. That combined with the very limited amount of power we put into the electric heat system can show whay it takes longer to cool the frig.
One of the big things on electric use in RV is that we often want to limit the large amount as we often expect it to be limited. If we want a frig to work off an inverter, we don't give it a great big 1500 watt heater!
So if we have a fair amount of cooling liquid and coils, combined with a small heat system, it does take longer to get it all up to the right temp to make it cool, but once it gets there, the electrical heat is fine for keeping it cool.
But it will never be as quick as we get on a home frig when we can use a compressor that does take lot more energy but does it faster.
The book does say we should start on propane for the quicker cool, rather than the slower.

But for this, maybe a look at page 29 on install/ ventilation may help look for somethingthat may have slipped out of place to block some of the venting of the heat on one portion or antother?

http://techsupport.pdxrvwholesale.co...rts-Manual.pdf

Something like a heat shield or baffle dropped to the wrong spot?
My first thought was the way my wife tends ot push things to the back of the frig where it blocks the cold air moving around but if the frig is empty, that doesn't fit, so maybe look at the back side or top? While looking be alert to any signs of the ammonia leaking, etc to reduce the cooling as it doesn't sound like you are getting the really cold stuff in the freezer.

[BobC]

You mentioned that you disconnected the thermistor, but did you check it? From what I've read, it should never read zero or infinite resistance. It seems that disconnecting it would be equivalent to infinite resistance:

https://thenorcoldguy.com/norcold-te...oubleshooting/

https://thenorcoldguy.com/norcold-th...e-2118-models/

In any case, if you were to order a replacement thermistor ($22) from The Norcold Guy, you get free technical troubleshooting support:

https://thenorcoldguy.com/

[CJBROWN]

I was concerned mine wasn't cooling well enough so I got a wireless thermometer, a sender for each compartment. Freezer is 5*, refer is 35* on setting 5 - Norcold.
I run a ARP board and a fan on the coils in the refer.

If you get tired of fussing with the old gas-absorption refer, consider switching to a 12V compressor cooling unit:
https://jc-refrigeration.com/product-information/

[BarryLS]

Thanks to all of you. I've gone over it once again and everything is exactly like it should be - level, no obstructions, door seals are fine, doors are closed, the thermistor checks good*, the controller has no error and it's clearly operating, and my expectation is not a problem as I'm more than prepared for it to take a day if needed.

I have two things I will need to check - one is the blocking test in the service manual that determines if you have an internal blockage, and two, checking the heating coil resistance to make sure it's working properly. It *might* not be heating properly. I need to get some propane in it and test with propane as well. That might solve the problem

I suspect I have a system that is at less than optimum and with high ambient temperature, it struggles. In that case I can use the freezer which is working and a cooler as required or I can fix the problem by replacing the entire unit or replacing the cooling system. I went to bed last night thinking I might just design a small compressor based system (I can do that) and replace the ammonia absorption system. Years ago I built my own AC unit for my garage with some old parts I had. I used propane as my refrigerant Anyway, along comes CJBrown with the link to already designed systems. That may take some of the fun out of it, and cost a bit more (I could just get all the parts from a dorm/compact fridge for <$200), but it is an engineered and proven system that keeps the current built in unit that otherwise I like.

So, we'll see what I find and I'll report back here the results, probably tomorrow if the weather cooperates.

I do appreciate the help. This forum really is priceless.

*yesterday I disconnected the thermistor to eliminate it as a problem. When disconnected it cools all the time. I also checked it, but since it was cold and my hand was warm, it was changing as the temperature increased, a good sign. Once I shut it all down I checked again and the resistance is correct for the ambient temperature.

[Bones2003]

Other posts that I have read over the years about this problem mention three other things to investigate. These seem more critical if your refrigerator vents out the side wall rather than the roof.
1) There is a specific routing for the airflow over the hardware on the back of the outside of the refrigerator. It is not good enough that the opening to the top vent be wide open. There should be a baffle that is properly spaced to direct the airflow near the top. As I recall, the spacing is surprisingly tight to make sure the air flows over the proper fins.
2) Newer refrigerators have thermostatically controlled cooling fans mounted back there to push even more air through that area. There are aftermarket fan kits you can add if your refrigerator does not have those fans.
3) On the sides, the refrigerator should fit tight in the cabinet so that there is not much airflow around the sides of the refrigerator.

You might try to find an installation manual for your model number. I have a different model number but the install manual shows the proper spacing.

[BarryLS]

Mine is a straight shot , straight up through the roof. Fairly large area at about 5wX20L or so. The sides are standard Winnebago. This is the unit that came from them. I haven't inspected the sides but they have to be preety close given the enclosure width.

Thanks, adding fans is probably a useful thing, particularly in hot weather. I may try that on a temporary basis if my last two tests pass.

[Morich]

Since you mention small frig, now might be a prime time to get one cheap. It depends on where you live and I do live in a college area which certainly changes things but I find lots of small frig right now set out on the curb and listed on Craigslist.

That is a special situation as college folks who seem to be way over financed do not want to bother with dragging a dorm frig back home,so they set it out for free!
And then they complain when they graduate with tons of debt! Wonder if there is a connection between throwing money out on the stree and being in debt? HUMM?

Maybe a chance to pick one up for free! Wine coolers are a frequent flier here as well?

[BarryLS]

Good point Richard.I'll keep an eye out. It would be a good cheap source of parts should I decide to roll my own.

[BobC]

Originally Posted by BarryLS

*yesterday I disconnected the thermistor to eliminate it as a problem. When disconnected it cools all the time. I also checked it, but since it was cold and my hand was warm, it was changing as the temperature increased, a good sign. Once I shut it all down I checked again and the resistance is correct for the ambient temperature.

Even though it's OK at the ambient temperature, did you check the resistance at more of the temperature points, especially at 80 and 32 degrees?

https://thenorcoldguy.com/norcold-te...oubleshooting/

Even if it's OK, I think I'd order a replacement from the Norcold Guy for $22 just to get the tech support.

How cold do the main compartment cooling fins get? It seems to me that, if the thermistor is OK, and since we know your system's cooling function is OK (the freezer works), then the main compartment cooling fins, and/or the controller board are suspect. I suppose there could be some something preventing coolant flow to the fins.

I did notice that the thermistor appears to have three connectors. Could one of them be bad? I don't know their function, they may just be specific to different model refrigerators, but if all three plug in somewhere, any one could be suspect.

https://thenorcoldguy.com/norcold-th...0-9000-models/

Have you seen this thread on IRV2.com? I didn't go through it's 8 pages but there may be something in it that helps:

https://www.irv2.com/forums/f258/nor...es-454200.html