Norcold N8X freezer cold, refrig hot

toolman.dustin · 07-08-2020, 08:26 AM

Last week I installed window screen over the air inlet of my refrigerator compressor panel to stop the mud daubers from gaining access. The refrig and freezer were working just fine. Now, the freezer is working but the refrigerator is actually hot. A little hotter than the inside air temperature.

I've read a few online articles about how Norcold units operate. Apparently my window screen has diminished cooling air flow enough to cause the cooling ability of the unit to fail.

I'll remove the access cover with the screen and see if that resolves the problem.

Is this thing designed so close to tolerance that disrupting air flow just a little is enough to make it fail?

Also, do I have to remove the refrig to gain access to the back of the unit? I don't see any way to actually gain access from the outside.

Ramn4ver · 07-08-2020, 08:57 AM

I've been working on this issue for 6 years. Here's my fix. Ducted top fridge with aluminum. (4th pic) to help get hot air out. (2nd pic) two 12volt fans on top vent to vent out hot air. (Pic 3) 12 volt fan too push in cool air at the bottom. (1st pic) 12 volt thermostat to set temp to have fans come on at 72°. Found thermostat on Amazon, along with q2 volt fans.0305201051_HDR.jpg 0305201213.jpg 0729180732.jpg 0709170750.jpg

toolman.dustin · 07-08-2020, 09:36 AM

Ramn4ver - thanks for the reply: ok, need way more air flow and still block the mud daubers. The hot air trapped between the back of the unit and the outside of the trailer transfer heat into the refrigerator making it hot inside the refrig. Get the heat out and it should start working again.

Thanks again.
Dustin

**Lloyd** · 07-08-2020, 09:58 AM

This was on the bottom of our forum page. It kind of goes along with your situation.
https://www.doityourselfrv.com/rv-refrigerator-tips/

Russb · 07-08-2020, 10:02 AM

Quote:

Originally Posted by toolman.dustin

Ramn4ver - thanks for the reply: ok, need way more air flow and still block the mud daubers. The hot air trapped between the back of the unit and the outside of the trailer transfer heat into the refrigerator making it hot inside the refrig. Get the heat out and it should start working again.

Thanks again.
Dustin

This should help. It has a larger mesh for less air flow restriction. Screens are also available for water heater and furnace.
https://www.etrailer.com/Accessories...10-1310VP.html

**dagst1** · 07-08-2020, 10:35 AM

The holes in the window screen are too small to allow ample air flow. Use a larger mesh or one designed for the refrigerator vent and that should help. Also remove the screen to see if proper temperatures return. On your camper the only access to the rear is thru the side vent and the roof vent. Otherwise you will have to remove the refrigerator.

You have a heat absorption refrigerator so there is no compressor. It does not make "cold" but absorbs heat leaving behind cold. On very hot days try to limit opening the door too often. So make sure you have ample air flow for it to work correctly. In the old days we would remove the lower vent and blow a electric fan in the opening on very hot days.

toolman.dustin · 07-08-2020, 08:14 PM

Quote:

Originally Posted by dagst1

The holes in the window screen are too small to allow ample air flow. Use a larger mesh or one designed for the refrigerator vent and that should help. Also remove the screen to see if proper temperatures return. On your camper the only access to the rear is thru the side vent and the roof vent. Otherwise you will have to remove the refrigerator.

You have a heat absorption refrigerator so there is no compressor. It does not make "cold" but absorbs heat leaving behind cold. On very hot days try to limit opening the door too often. So make sure you have ample air flow for it to work correctly. In the old days we would remove the lower vent and blow a electric fan in the opening on very hot days.

Found this Youtube video that does a good explanation of how absorption refrigerator works.
"

https://www.youtube.com/watch?v=b2J61TkKsJ8

"

harley · 07-09-2020, 07:09 AM

Take off the outside vent and put a regular fan pointing into and upward the opening. Give it a few hrs and see if air flow helps. If so add a couple compute r fans.

toolman.dustin · 07-09-2020, 08:19 AM

Quote:

Originally Posted by harley

Take off the outside vent and put a regular fan pointing into and upward the opening. Give it a few hrs and see if air flow helps. If so add a couple compute r fans.

That's what I did. Removed the outside cover, defrosted the freezer for 6 hrs. Installed a fan to ram air up through the vent opening and behind the refrig. Restarted the refrig. Took about 9 hours but the refrig and freezer are both now cold. I've ordered the insect screen for RVs, less air flow restriction.
Still looking into this but I may install one of these bilge pump blowers. They move higher volume of air than computer fans.

" https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1 "

Thanks for the help from everyone.

Dustin

toolman.dustin · 07-09-2020, 11:59 AM

Here's the root cause of the reduced air flow when I installed window screen.
I went out to take measurements for installing a fan. Turns out the screen I installed was 100% blocked!. I ordered a roll of adhesive backed window screen screen 2" width. After removing the backing material and sticking it in place I failed to notice the clear film of adhesive that was stuck to the screen. It did not get removed with the backing material. So the entire screen was 100% blocked with adhesive.. This makes sense now. I was really struggling with how the temp in the refrigerator could climb to 120 degrees.

I've already ordered RV screen mesh and I'll probably go ahead and install a fan. Certainly couldn't hurt.

4kids2dogs&RV · 07-09-2020, 02:47 PM

Ouch, glad you figured it out now, you would have had a lot of head scratching going on after installing the fans.
I do appreciate the discussion though, hopefully it will help others that have cooling issues in the future. I know i learned a few things.
Cheers!

**dagst1** · 07-09-2020, 03:21 PM

You may want to pull the cover on the roof vent for the refrigerator just to check for a obstruction. Things like to build nests there and you should check there every year when you de-winterize. Also while it is off look down in behind the refrigerator and see if there is a fan from the factory. Our cruiser has one but the refrigerator is in a slide. The camper before this one had one and the refrigerator was not in a slide. They are on a thermostat so they do not run all the time so you may never hear it.

toolman.dustin · 07-09-2020, 08:46 PM

Quote:

Originally Posted by dagst1

You may want to pull the cover on the roof vent for the refrigerator just to check for a obstruction. Things like to build nests there and you should check there every year when you de-winterize. Also while it is off look down in behind the refrigerator and see if there is a fan from the factory. Our cruiser has one but the refrigerator is in a slide. The camper before this one had one and the refrigerator was not in a slide. They are on a thermostat so they do not run all the time so you may never hear it.

I'll do that. I found an electrical schematic online for my model and it says there's a fan and that fan is wired to the thermister inside the refrigerator. So when the refrig says it's time to cool it turns it on the cooling process along with this fan (assuming it's actually there).

Thanks everybody!

toolman.dustin · 07-12-2020, 11:22 AM

I hate to re-activate this post but I have a new question:
I took the cover off the top of the refrig at the roof and there's no cooling fan anywhere. After studying the schematics and reading the online service manual for my model refrig: I've determined the cooling fan is an option (which I don't have) and the cooling fan is controlled via a thermostatic switch located on the first condenser and turns the fan on at 130 deg F and turns it off at 115 deg F. My plan is to install cooling fans at the roof top to pull cool air through the entire back of the refrig unit.

My question is to those of you who have expertise in absorption refrigeration; is the thermostatic switch necessary? What happens if I have the fans come on anytime the unit is cooling regardless of temperature and have them shut off when the cooling cycle is completed? I wouldn't think there was such a thing as "too cool"?

**Lloyd** · 07-12-2020, 11:26 AM

The only part of your question I can answer, is yes, there is such a thing as to cool for the absorption fridge.

They don't do very good in cold weather.

Ramn4ver · 07-12-2020, 12:01 PM

Took me a triple check to find the original fan behind our fridge. It is very small and in the middle of the fridge, on the back wall.
Yesterday was 99° outside. Both fridges stayed right at 37°. I'm so happy not having to deal with anymore fridge issues.

toolman.dustin · 07-12-2020, 02:03 PM

Quote:

Originally Posted by Ramn4ver

Took me a triple check to find the original fan behind our fridge. It is very small and in the middle of the fridge, on the back wall.
Yesterday was 99° outside. Both fridges stayed right at 37°. I'm so happy not having to deal with anymore fridge issues.

I'm catching up to you. Actually, if you recall this was a problem with mud daubers. I didn't have a problem until I tried to stop the mud daubers. But, anything worth doing is worth overdoing so here I am fixing a cooling problem I didn't have. I don't have a fan. My controller would turn the fan on/off using pins 1 & 6 of the controller board. There are no wires attached to pins 1 & 6. And, I'm not certain pins 1 & 6 are active on my controller.
So, I've decided to install a thermal switch to turn the fans on at air temp of 90 degrees and off at 70 behind the refrig. Picked those numbers at random. And I can lock the mud daubers and wasps out as well. I'll post a couple of pictures when this is all done. This thread might help someone else some day.

And..... while I had access to the top of the refrig via the vent,, I pulled a 12 volt power wire to the kitchen vent about 30 inches. Now I can install a reversible Fan-Tastic vent fan.

Thanks again to all:

toolman.dustin · 07-15-2020, 03:30 PM

So installed 4 vent fans (computer fans) at the top of chimney. Turned on the refrig about 24 hours ago. I put two thermometers in, one in the freezer and one in the refrig. The freezer is now -4 deg F and the refrig is 16 deg F. The front panel control is set to the warmest setting. In the refrig I slid the thermocouple all the way to the bottom of the fins. It's 96 degrees outside and 102 degrees inside the trailer.

Surely I'm not going to have to disconnect these fans to warm up the refrig?

Any ideas?

toolman.dustin · 07-15-2020, 06:04 PM

Update:
Never mind --- I decided to swap the thermometers around and see what happened. So the refrig now reads 45 (was 16) and the freezer now reads 16 (was -5). So I have a defective thermometer. All is fine after all.

Stan · 07-15-2020, 10:23 PM

I have been following this thread and am glad you are getting your situation back to normal. I will say that on my rig, the fans didn't really come on at the correct temps so I disconnected the thermal switch and added a manual switch to turn the fan on/off as the outside temp dictates. When I replaced my fridge a few years ago I really studied the manufacturers directions and found out CR did NOT install the fridge correctly. There is a lot of ducting requirements that were not adhered to. My new fridge works great. I wrote a long informational post on what I did and should be searchable on this forum if interested.

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