Cold Weather Fridge Troubleshooting Need Some Help

[jtrader]

I have a Norcold N611 Fridge/Freezer in my 2013 Grey Wolf and It's giving me some fits. Have had no problems in the colder weather for the last three winters and temps would get at or below zero for days at a time.

First sign of trouble was 3 days ago we noticed everything was thawing out in the freezer and getting warm in the fridge. Outside temp was still in the mid 20's or higher. Went outside and took off the access/vent panel and heard a faint high pitched tone. I immediately thought my motherboard was fried so I looked there first. Found a stink bug cozied up right across the two wire connections on the motherboard. I immediately unplugged the fridge, got rid of the bug and decided I'd better check the two fuses under the motherboard cover. Both of those were fine. I went inside and turned off the breaker and also pulled the DC fuse for the unit. I waited a good ten minutes then turned everything back on (plugged the fridge back in, turned on the breaker, replaced main 15amp fuse) with the fridge set to the coldest setting. No high pitched noise and the fridge began cooling again. Overnight cooled everything down back to normal.

The next day temps started to drop outside. we had single digit lows overnight and the fridge didn't seem to be up to speed. I turned it to gas to see if that would help with more intense heat. Seemed to do a good job but not what it should on the coldest setting. Temps were only going to drop from there so I went back to the access panel and closed off 90% of the vent holes in the panel with aluminum HVAC tape. I also cut a scrap piece of 3/4" foam panel and covered 80% of the backside of the panel closest to the burner to insulate it a little. I made very certain to give it enough air to breath as well as made sure the foam wasn't close to anything to cause a problem. After the mods everything worked 100% so I switched it back to AC and it held temperature.

We had -8 degree temps that night with the fridge on AC and the next day everything was just fine. Last night was warmer but the wind really picked up out of the West which is the fridge side. This morning things were doing fine at 17 degrees but wind at about 20mph. Just noticed ice cream was almost completely thawed. We're at 9 degrees with a wind chill at -6 coming from the West again.

I switched it back to gas. It seems to be cooling down again but won't know for sure until tomorrow. I'm thinking it might be the AC heating element giving out after 2 1/2 years of continuous use. Could that be the issue or do I need to look at the thermistor too? I don't think the cooling unit is bad as there are no signs of a leak or any type of ammonia smell and from my limited knowledge it doesn't sound like the mother board has quit just yet or it wouldn't work on gas either.

Sorry for the long post, just wanted to make sure you guys new what I had already done. Any help would be much appreciated.

[arpipeliner]

Have heard of people closing off both panels on electric. Something about the freon not working right in the extreme cold.

Have seen a post on here before about this. Haven't experienced it myself yet to know for sure. Sure others can help and know more than me.


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[youroo]

First off when using the (Propane) side (NEVER) close off any vents!! That trick can (KILL)! Now run on elect.if this is not doable use a cooler. Are you trying to live in this unit at these Temps? These units are (NOT) made for Temps in this range! Youroo!!

[jtrader]

I normally run it on AC 100%. When I did reduce air flow I made sure there is still plenty of ventilation for using on LP if needed (roof vent still 100% open and bottom vent probably 20-30% open). Main goal is to block the wind from sucking out all the heat to allow the ammonia and hydrogen to boil. I think I've done that by shifting the draft farthest away from the heating tower.

My wife and I are full timing in this trailer while saving to start a homestead. Over time I've made some modifications to beat the cold. Takes a little work but is proven doable comfortably and safely.

My main concern is the motherboard after hearing that faint high pitched tone. If I have to replace the motherboard I think I'll scrap the whole thing and install a residential 4.3cu ft AC unit. If it's the element or thermistor that's a more reasonable not to mention affordable fix.

[bruane]

I assume that this is in degrees F not C. If that is the case i would venture that this fiidge is not designed to run in an ambient temperature of -8F and requires it to be in the range that a habitable room would exist in. A domestic fridge will not run outside in the cold as its sensors tell it that the heating/cooling cycle required for it to cool internally is not needed.

[jtrader]

Yes F not Celcius. At first I thought it could be the cold but when the problem occurred originally it was in the 20's-30's. I have never had a problem in those temps before. Last winter we had a cold spell with high temps never getting out of the teens and lows every night below zero for two weeks and the fridge worked fine the whole time. Last night we had lows in the teens and night before in the single digits but the fridge worked fine. The high pitched noise is what bothers me and I can't get it to repeat the problem.

[bruane]

I had this problem with a fridge installed in a cold area. The trick to finding out if the frige is working OK at the cold temperature it is in is to warm the thermostat (just put your hand around it) and if it kicks into life the fridge is working ok and its ambient temperature is too low. I would say that 20F to 30F ambient is in the marginal range for this kind of operation with a normal fridge.

[jtrader]

I'm sure you're right about the marginal range. I know these cold temps are pushing it. The measures I've taken to keep the wind out of the cooling unit area seem to have helped considerably though. I'll try your suggestion with the thermistor tonight. It seems to be working fine the last two days. Thanks for the suggestion.

[bruane]

Good luck with cold work! You should try going to the Web and looking for the specs on this fridge. They should give guidance on installation environments

[Flybob]

The fridge works by the small heating element boiling the liquid in the boiler to cause it to evaporate. If it is very cold, ( especially if it is windy) the electric element may not generate enough heat to sufficiently boil the liquid and the cooling will be compromised. The propane generates a little more heat and hence can extend the operating temp range a little.

[RamblerGuy]

I think you found the main problem by restricting the air flow.

Ford's RV Training and Service specializes in RV refrigerator repairs and training for repairmen. They have videos online that are very informative. Two of the videos discuss heating elements.

http://rvrefrigeration.com/training-videos/

In one of the videos they said that during very cold weather there's too much air flow through the chimney and it doesn't properly heat the refrigerant. To test a unit, they taped cardboard over the lower access panel to cover about 80% of the opening.

As for the A/C heating element, electric heating elements seem to either work or not work, not deteriorate over time. If you can remove the element, it should have the wattage stamped on it.

If you can’t test the wattage of the element in place while it is operating by measuring the amps and volts, you can at least check the resistance, which should tell you if it is good. With the power off, disconnect the wires to the heating element and measure the resistance. It will be directly proportional to the wattage that the element puts out.

To calculate the resistance, use this formula: R = V squared divided by the wattage. I don’t know the voltage that they use for the wattage rating, so I’ll assume they used 115 volts to get a number. For our Dometic with a 325 watt element and 115 volts, R = (115 X 115) / 325 = 40.7. If the resistance isn’t close to this, the wattage it’s putting out won’t be close enough to properly operate the refrigerator, especially with cold outside temperatures.

As a side note, considering how you are using your RV, I fully agree that if you can’t get it fixed quickly for a reasonable cost, just buy a small residential refrigerator and worry about the RV refrigerator later.