Norcold freezer cold, refrigerator not so much

[BarryLS]

Alright, a bit more added to the pile of understanding.

I checked the heating coil resistance. The spec is 40.3 ohms and I'm right at it, 40.6, so the heating coil is eliminated.

"Blocking" is not an issue per the service manual test. After 45 minutes of running, the absorber coils are hotter at 130 than the flue canister at 105, so that issue is eliminated.

While checking the heating coil it dawned on me that since the only thing required for the cooling to occur is that coil heating up, then directly connecting it to 120vac would bypass everything else, control board, thermistor, etc.

So at 2:15 I connected the coils directly. The inside temperature of both compartments was 81 and the ambient temperature is 81.

At 3pm the freezer is 69 and the fridge hasn't changed. I expect the freezer to have to drop quite a bit before the refrigerator begins dropping.

At 3:30pm we have 48 in the freezer and the fridge is now dropping and down to 78.

I'll let it run this way and see what we get.

Also, I'll note that reading the install specs from Norcold and examining the install from Winnebago suggest Winnebago also read the manual. The installation looks proper, including a baffle in the chimney to direct the airflow correctly.

Bob, I did check the thermistor and it's fine assuming the connections are good when it is connected. I don't know how cold the fins get. I don't want to open it to find out but I will when I get to whatever end this test has. I've read through all the norcoldguy stuff but see no answer to my issue given everything I check says "good to go".
That thread is appropriate to my problem. I'll read through it but think I already have. Appreciate the link.

If I see that same problem then it means the control board is fine. And if not it may just mean it's not as hot today.

If the problem persists I see two more things to check/do, requiring the removal of the Norcold to access -
1. Clean the flue and baffle
2. Check the sealing and attachment of the cooling unit to the rear of the unit. At 24 years old who knows if that is intact.

And, I need to get some propane or connect one of my small tanks and see how it does on gas.

[BarryLS]

5pm update:
We have 22 in the freezer and 68 in the fridge. Ambient is 84 this afternoon.

I'm happy with the freezer dropping that much in a bit under three hours. And the refrigerator is at least going down.

[Morich]

That sounds like you may be headed to "OK" but it takes time. Getting the propane may let you speed up testing as it does do things quite a lot quicker.

When doing the thermistor back, look at how it connects on th efins as it helps make it more accurate if it reads the temp better.
But the book is far better info on how to do that than my memory!

[dkoldman]

Originally Posted by 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?

Originally Posted by 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.

I got a Galanz fridge that has been sitting in our Dining room for few years now. My wife bought it for our son and we haul it all the way to school for him, but they lived in condos so after a year he did not want it. Bring it back home and it sits for a year and we repeat with our daughter, after one year she brings it back I tried to set up in our formal living room but I never want to go in there to get a drink. We have outdoor kitchen fridge in RV already. So one day I will figure what to do with it. Not worth trying to sell or ship, but too good to throw away. I wish I had the OPs problem; so I could put it to use

[BobC]

I never asked or saw anything about it but have you tested it on LPG?

In any case, complete cool down can take at least 24 hours an is quicker on LPG than on 120V AC.

Step by step, you're getting to a solution.

[dkoldman]

Originally Posted by BarryLS

5pm update:
We have 22 in the freezer and 68 in the fridge. Ambient is 84 this afternoon.

I'm happy with the freezer dropping that much in a bit under three hours. And the refrigerator is at least going down.

This is very consistent with what I reported in post #5

I got to 32 in 2 hours for freezer. I believe your ambient temperature is about the same (83 for me). My money says you will hit 45 degrees in the fridge at abut 10:00 pm your local time. You Freezer will be at 4 degrees.

[BarryLS]

7:15, 5 hours of operation with no door openings and the 110vac connected to the heater coil directly. We are now at 11 on the freezer and 59 in the refrigerator. Started at 81 so we've dropped 70 degree's in the freezer.

Since I have thunderstorms predicted overnight I'll have to stop around 11pm to recover my roof. I have the area above the refrigerator vent pulled back.

Bob, no, haven't tested on gas but I've mentioned it above. I think I'll get what I need to connect a 20 pound tank temporarily, just for testing.

dkoldman, I hope your prediction is right. I could live with 45 in the fridge. The question will then be why it's better than the other day. Could be the bypass of the control board but I'd be surprised if so. I already know it's not the thermistor since I ran with it disconnected and the fridge still didn't get cold enough. Just have to wait and see what she does this evening.

Richard, I've eliminated the thermistor as "the" problem since disconnecting it causes the control board to operate on all the time. I've also checked the resistance and it's good. At the moment it has no bearing on the temperature since the heating coil is connected to my extension cord.

Pictures!
1 is the 2:15 starting temps
2 is the 7:15 temps
3 is the heating coil hooked directly to my extension cord with a plug cutoff just to show how it's done for someone that would like to test this way
4 is a pic of the control board with cover removed and wires disconnected. The 110 plug had to be moved to get to one of the cover mounting screws (lower right)

[dkoldman]

Originally Posted by BarryLS

7:15, 5 hours of operation with no door openings and the 110vac connected to the heater coil directly. We are now at 11 on the freezer and 59 in the refrigerator. Started at 81 so we've dropped 70 degree's in the freezer.


Pictures!
1 is the 2:15 starting temps
2 is the 7:15 temps
3 is the heating coil hooked directly to my extension cord with a plug cutoff just to show how it's done for someone that would like to test this way
4 is a pic of the control board with cover removed and wires disconnected. The 110 plug had to be moved to get to one of the cover mounting screws (lower right)

I hope you stocked it with enough beer for all of us. I will be sure to get mine before it freezes or before 11:00PM; whichever comes first

I think it may all be related to ambient temperatures and humidity.

[BarryLS]

Heh, the wait is over, the final results are in, the roof is recovered. I just hope we get some rain, it's dry as heck around here.

11pm: 6 degree's in the freezer and 53 in the refrigerator. The fridge cooling fins are low 40's on the right side to high 40's on the left side. Ambient temperature is 75.

So, freezer is fine, fridge not quite what I'd like. Perhaps if I left it running a bit longer... but really not that useful if you're going to open and close it a few times. I expect that when using in high ambient temperature the results would be better if the AC were running and the MH inside temperature was in the low 70's.

It's close. Another 5-6 degree's in the fridge and I'll be OK with it as is.

I have to travel to see a customer tomorrow but will continue on Thursday. I'll connect the board back up and just make sure I can get the same result without the control board bypassed. The next step will be to remove the unit and clean the flue and baffle and check the fitting/sealing to the back of the unit. That may be a while but I'll come back and update this thread with the results. While it's out I can design a compressor retrofit if I decide to roll my own, which is highly likely should I decide to go for more/faster cooling. I like the size and design of the built in.

I sure appreciate all the help. It does make a difference and this forum is great.

[Morich]

Maybe as a smaller job but to get better performance, a computer fan up top to pull venting air up and out would be fairly simple? One good thing about them is they come in all sizes to fit the space and all voltages (12DC or 110AC?) to fit whatever power source you have best. They are quite, use little power and often cheap or free if there are old computers setting around on the curb!
Or maybe we have one back in the closet, just hanging around? I used to use several to cool fish tanks!

[BarryLS]

Richard, yes excellent idea. I had thought of it earlier to help when outside temps were high but had misplaced that thought. Should be simple to add.

[BobC]

I wonder if part of the problem is an empty refrigerator. Norcold recommends pre-refrigerating food before you load it. You might want to try cooling down some jugs of water and putting them in your Norcold and see if it can then keep up.

[BarryLS]

Could be. It's always better to have a full freezer / refrigerator when opening and closing to limit the amount of air that spills out and replaced with air that has to be re-cooled.

OTOH, the flue cleaning is part of the maintenance that is supposed to be done but I bet doesn't happen when it should. Norcold says once per year or after any prolonged shutdown. I'd bet this is almost never getting done.

[Morich]

Got a leaf blower handy?
I found one handy for sucking/blowing things like wasp nests out of the vents on furnaces!

[BarryLS]

Hey Richard, leaf blower I have!

However, the flue stack apparently gets soot from the propane building up and has to be cleaned with a flue brush and the baffle with a brush or emery cloth. It's not stated but I suspect the buildup inhibits heat transfer, which would be in line with the problem I have. I hope it's as simple as that, clean it and pick up another 10 degree's or so

[Mikeknapp]

Inexpensive try. Replace the thermistor. A little sensor clipped to the silver cooling vanes. My fridge had a similar issue. We sensor did the trick. Good luck!

[sgtstriker]

Okay, you have apparently done all of the tough stuff, now let's go with some simple suggestions;


1. Pour some water down the the drain at the rear of the refrigerator section until you see water coming out of the drain hose on the exterior. These refer drains, like household drains, have "P" traps in them. If your rig has sat a while it's likely that the water sitting in the trap has evaporated and warm outside air is entering your fridge...
2. Put your thermistor at the highest point that you can on the fin farthest to the right in the frig.
3. Place a small battery operated fan in the fridge to circulate the cooler air.
4. Expect up to 2 days for the frig to get down to desired temps......



Sometimes it's the simple stuff....


Good Luck...

[JohnTex]

At 90 degrees and above, there is not sufficient temperature differential to get effective air flow through the chimney. Consider adding fans to help move air through the chimney

[2lgdterrier]

Hi all. I have a Norcold N3150 my unit is a 2016 so the fridge is 2014 or 15. it does exactly as you describe freezer adequately cold, refrig not so much, high 50’s low 60’s after days, yes with ore cooled contents. No fridge should be checked empty zi think. They need a heat/cool sink the contents help even out. I have checked everything suggested here. The odd thing is last year on way home, final trip both area’s cooled wonderfully. So I thought ahhhaaa fixed, not so this year. I keep getting hints, comments to check the fan, that makes sense, what fan though? I cannot find one and think there should be one either inside or on the back. Sooooo? All info helps. Thank you.

[Morich]

I don't see a fan on that model and do find mention of adding one.

This is a site which I found but before recommending it, I would say it is not the "official" Norcold site and seems meant to sell their product!!! Beware those who might trick us? We have had about all the tricks I can stand, so be alert!

It DOES show how to add a fan, however and that might be something of interest to you.

https://www.viewnavionmotorhomes.com...ications-1.pdf