Norcold N821 takes FOREVER to get to cool temps

[Ron_Nielson]

I have a 2008 model Norcold N821 2 stage refer in my 5th wheel that up until a week ago was flawless - on both electricity and gas. We parked at Prescott AZ last year all summer until late August; temp control set at 7 would freeze the lettuce (though the beer was really great), so had to reduce to 5. Trailer sat unused until about two weeks ago, turned on the refer to cool down prior to a trip. It was on electricity part of the time and on gas the balance of the time. After 3 days of being on (and empty), freezer was at 27, fridge was at 50. Days were at 90 and nights 75 with high humidity. Loaded the frozen and cold food overnight and temp came down to 40 in the fridge and freezer still at 27. Left to go on the trip and 2nd night out the overnight outdoor temp was in the high 40's, fridge was at 35 by the morning. Daytime temps in the 70s. Came home on 4th day and now at day 5 freezer is at 0 and fridge is at 34 with temp setting on 7.

So what's going on with this refer? Definitely not normal to take 5 days to cool down in moderate temps (79* outside now, about 60 last night). Not a gas problem, or an electric supply problem - they both have the same result. I have 2 large computer fans blowing up thru the back of the fridge and it's as clean as can be up there - no blockage. I have 2 small computer fans attached to the fins inside to circulate the air. Tried removing the thermister from the fins to see if that might be the problem, but no real change.

The refer definitely cools, is just takes a REALLY LONG TIME. Trailer is stored very level and we level pretty precisely when we're out using it. I don't THINK it's a cooling unit problem.

I have heard of a main board electrical 'reset' but do not think this is likely to help my situation. Can someone explain what this reset does and what it's purpose is? Any suggestions to determine what the problem might be?

[jcpainter]

Ron Nielson wrote:
There is a document that exists on the internet titled 'publication 631361a' Google that and you will find one choice under Bryant RV named Norcold Electronics Troubleshooting, which is a .pdf file with all the instructions and information.

to Start, press and hold TEMP SET and MODE at the same time, release when you see a 1 on the display. Pressing the mode button will get you to the next selection. To get to out of this, turn refrigerator off, and then back on. You really need to look at the .pdf file, and have knowledge of the board number for your refrigerator. Mine was 628661 and it's printed at the edge of the board.

Thanks!

[Ron_Nielson]

There is a document that exists on the internet titled 'publication 631361a' Google that and you will find one choice under Bryant RV named Norcold Electronics Troubleshooting, which is a .pdf file with all the instructions and information.

to Start, press and hold TEMP SET and MODE at the same time, release when you see a 1 on the display. Pressing the mode button will get you to the next selection. To get to out of this, turn refrigerator off, and then back on. You really need to look at the .pdf file, and have knowledge of the board number for your refrigerator. Mine was 628661 and it's printed at the edge of the board.

[jcpainter]

Ron Nielson wrote:

Old-Biscuit wrote:

Ron Nielson wrote:

Old-Biscuit wrote:

What day did you mess with thermistor and change temp setting from 5 to 7?
Day 3 day 5?

DO the direct electric element test.

Have you checked the 'diagnostic screens'?

What day did you mess with thermistor and change temp setting from 5 to 7?
Believe that was day 3. Not absolutely certain.


Diagnostic Screen Results:

#1 - Diagnostic mode active- Results OK all segments lit
#2 - Led Segments Reliability Check - OK
#3 - Thermistor Fin Temperature - OK - 62*
#4 - Stored Faults - OK received Door Ajar and Ignition Fault
#5 - Stored Fault History - Thermistor Failure (possibly because I removed thermistor from fins?)
#6 - Erase Fault History - done
#7 - Power Board Inputs - thermistor sensing fin temperature
#8 - Power board outputs - AC power to AC heater and DC power to divider heater
#9 - Power Board DC Voltage Status - DC voltage normal
#10 Power Board AC Voltage Status - AC voltage normal

Will do the AC direct power tomorrow.

Ron, how do you get get these diagnostic results on the N82? We have the same model and are having similar problems.

[jcpainter]

Skid Row Joe wrote:
FWIW, propane fired absorption RV refers cool much better on propane than 110AC. However, in a perfect weather scenario - either mode; propane/110AC would do equally as well. Good luck!

I'm a bit confused on this statement. The first sentence says that the frig will cool better on propane, the next sentence says that the frig will cool the same on either propane or 110. Perhaps I'm having a senior moment and reading it wrong.

Does one cool better than the other?

[Old-Biscuit]

So new thermistor and fridge is cooling down almost the same temps on electric and propane.....GOOD!

Got a spare relay?

[Ron_Nielson]

Freezer -5, fridge 32 morning after start. I'm calling it good. No improvement needed. No more parts to buy.

[Ron_Nielson]

New thermister installed today. Still pulling 289 watts, 2.45 amps at the 120v receptacle for the fridge. So fridge is not pulling all 300 watts, although very close, that the heater itself should draw. Will see how long it takes to cool.

[Ron_Nielson]

Ron Nielson wrote:

dougrainer wrote:
But, you still have a 120 volt supply problem. UNLESS, you have an aftermarket 120 element or an Element that is NOT the correct wattage for your refer. That is why I would want to know the amp draw of the element. Doug

Doug

The 120V heater is original to the refrigerator. When tested independent of the control board, the refer works just fine at ~114 volts. So I am fairly certain that the problem is not (primarily) the heater, and that's why I think it IS the control board.

Just to satisfy those who say 'replace the thermistor', I have one on order and will test again with a new thermistor. As pointed out, it's only $15 (and less work than replacing the board) and a board is $100. I'll wait to buy the control board until I've tested with the new thermistor, just to be sure.

I forgot that I had a plug in meter (Kill a Watt) to test volts, amps, etc on a 120V circuit. So I plugged it into the receptacle and the refrigerator into the meter and at 118.0 volts, it indicated 2.45 amps. That comes to about 289 watts (I forgot to look at the watts indicated on the meter) which is just a hair short of the 300 watt rating of the a/c heater itself. I just did this to check the draw for about 30 seconds. The fridge had been turned off for several days and was quite warm.

[Ron_Nielson]

Relay ordered.

[wnjj]

Ron Nielson wrote:
Yes, the picture is the exact number of the board in my trailer. I got the number from the board, went to Amazon, selected the board and put in in the cart, then marked it 'save for later'. I did not check to see the labeling of the relay, k1 k2 etc to compare to the picture or a wiring schematic. The trailer is a 2009 model but was built in 2008, August, IIRC.

Do you want me to remove the board cover so that I can visually see the board? Maybe I'm looking at the wrong relay?

Here's an Omron replacement available (but backordered a little) on digikey. It has the same footprint, 5VDC coil voltage and current as the Goodsky one. The only difference is a 16A AC contact rating instead of 15A (more is better but the contact need only support a couple amps for the heater anyway.

http://www.digikey.com/product-detail/en/G5LE-1A-E-36%20DC5/Z5217-ND/1815659


Here are the two datasheets for reference:

Omron datasheet

Goodsky datasheet


Apparently Norcold did change the board design some so the schematics I linked may be off a little. The manual I found has a 16-pin connector which apparently they changed to separate 10-pin and 6-pin ones in recent designs. If your board matches the Amazon one, the Omron relay will work.

[Ron_Nielson]

Yes, the picture is the exact number of the board in my trailer. I got the number from the board, went to Amazon, selected the board and put in in the cart, then marked it 'save for later'. I did not check to see the labeling of the relay, k1 k2 etc to compare to the picture or a wiring schematic. The trailer is a 2009 model but was built in 2008, August, IIRC.

Do you want me to remove the board cover so that I can visually see the board? Maybe I'm looking at the wrong relay?

[wnjj]

Ron Nielson wrote:
The relay appears to be a Goodsky rwh-ss-105dmf-u

RELAY

I don't see that one nor K2 on the Digi-key website. Must not be doing something correctly on their search.

Does your board look just like that one on Amazon? The reason I ask is the Goodsky relay on there is labeled "K1" on the board but the schematics here show K2 as the relay for the AC heater (page 48). The pictures of the boards on page 45 also look different than the Amazon one. The manual is from 2003 but your 2008 shouldn't be that different.

The relay in question is a 5V coil, switching 15A/120V AC. I couldn't find an exact replacement on digikey either but before I spend more time I want to be sure yours is that one.

[Ron_Nielson]

The relay appears to be a Goodsky rwh-ss-105dmf-u

RELAY

I don't see that one nor K2 on the Digi-key website. Must not be doing something correctly on their search.

[wnjj]

Ron Nielson wrote:

wnjj wrote:

So it is looking more likely that the relay and/or control board is bad. I'd follow Chris' advice to see if you can catch it in the act. A relay is cheap compared to a whole new board.

I agree, and easier to install. If only one could be found for purchase! I looked, but didn't find anything available, other than mounted on a board. If there is a source, please post.

If you can get the part number or specs, digikey.com will have it. If there are any markings on it, take a photo of the relay and post it here. I think it's relay K2.