Norcold N611 Cooling issue

[duck1973]

Hello Everyone!

I have a Norcold N611 refrigerator/freezer unit in my RV. This past year it started having cooling issues. Earlier this year I took it to the local RV repair shop to have it looked at. About a week after dropping it off they called and said my power converter was bad. They replace that and said all was good. I had my doubts.

$351 later I brought the RV home, plugged it in and unit cooled like normal for a couple days then without having the doors open the temp rose to 35 degrees in the freezer and fridge was in the 50s. I left it and later that day it cools back to normal of -3 to 0 degrees in the freezer and normal fridge temps. This is exactly the same issue I had before.

After reading online and doing some troubleshooting I bought and installed a new thermistor. Everything operated normal for 5-6 days and then again the temps rose again.

Today I followed Norcolds flow chart for troubleshooting. Checked the fuses in the power board. Everything seems good. I decided to disconnect thermistor and now my freezer is at -7. That's the coldest I have ever seen it.

Anyone have any ideas? Thermistor checks out good.

Thanks in advance!
duck1973

[Old-Biscuit]

BFL13 wrote:
https://norcold.com/wp-content/uploads/2018/07/636355B_SM_N611vN811.pdf

That LINK is for the N611 'V' series...slightly different then OPs n611 Model


OP....
With thermistor unplugged you should have a 'Fault Code' (ON LED Light FLashing)
That would indicate bad thermistor/unplugged thermistor and fridge cooling cycles would be controlled by the 'Backup Operating System (BOS)

BOS continues to allowing heating cyles to ocurr but instead of being based on FIN Temp they are based on 'Time' durations
You can adjust temp set point to change time duration
-10*F/freezer sounds like you have temp setting at '5' (Max cold)

What temp is food comaprtment running at?????

Thermistors can 'test' good (resistance) and still be faulty
Connection at lamp assembly/leads etc can cause issues with temp feedback

Freezer & food compartment temps COLD w/o thermistor plugged in means cooling unit is capable & functioning

Thermistor leads clean, plugged into clean sockets at lamp assembly and making good contact on 10th fin from right should allow for proper temp control

If Not........replace with another OEM thermistor OR an aftermarket Rheostat type such as Snip The Tip (for Norcold)
Norcold Snip The Tip


Norcold N6/N6 Series Service Manual

[BFL13]

https://norcold.com/wp-content/uploads/2018/07/636355B_SM_N611vN811.pdf

[duck1973]

Let the unit run over night with the thermistor unplugged and this morning freezer is at -10 degrees. I have never seen it get this cold.

I feel like something with the new thermistor still isn’t right.

[DFord]

Give the tech at Dinosaur Electronics a call:
https://www.dinosaurelectronics.com/
They're good people and can give you advice about what to do next.
There boards have a longer warranty than Norcold's.