Refrigerator Performance & Unusual Control Issue

[SmackIt]

I have a Norcold Model N8V refrigerator in my 2021 Surveyor trailer. It's pretty much a typical American made garbage product the industry loves to dump into today's RV's. We've camped about 30 days this year. It's a rare occasion this fridge will perform adequately. I've read dozens of threads, and watched plenty of videos. I've put fans on the inside and fans on the outside. Typical performance for this unit on a 80ºF day with the fridge side of the camper shaded is 22ºF Freezer / 43º Fridge.

Let's get the obvious out of the way.

• This unit has a grand total of 1 control button and a resistor on the cooling fins. That's all you get to fiddle with for adjusting the temperature.
• We now have family meetings and planning sessions on when to open the door to extract items from the fridge. It's rare the door is open more than 10 seconds.
• Nothing is ever put into the fridge that hasn't been pre-cooled.
• Fridge is packed to about 65% capacity. All items are arranged in strict airflow patterns to avoid any chance of uneven cooling.
• The dealer insists the fridge is operation "within spec" and seems to think my request for a freezer below 10ºF and fridge at 35º is "not the way RV fridges work".
• I know about the "secret modes" of High/Medium/Low you access with a 30 second press of the power button.

I've got 540 Ah of LiFePO4 batteries and 900 Watts of solar. This fridge devours 300+ watts all day long, so running it on electric is not a great option. I only share this info as it is an option I've tried, and the performance is roughly the same on both gas and electric.

Issue #1
I'm in the middle of some advanced fan integration in the exterior compartment. I'd like to know if it's possible to "overcool" any parts of the cooling system on the exterior of the fridge under normal use with outdoor temps between 65ºF - 90ºF. Is there anything on the back of the fridge in that compartment that shouldn't have cool air running over it?

Issue #2
The default logic of the fridge is...
If AC electric power is available = Run on AC electric power.
If no AC electric power is available = Run on Gas.
You can force the unit to run on Gas when it's plugged into AC electric by long pressing the power button. That is the mode we generally run in because our inverter is always running from the solar and batteries when we camp. On two occasions, the fridge was running on gas and quit for no reason. There was plenty of gas in the tanks (over 70% full), I suspect a strong wind might have blown the flame out. Both of these occasions resulted in temps going above 55º in the fridge and the loss of food. On both occasions, the fridge did not try to restart on gas. Is there any way to force the unit to go back to electric if the gas mode fails? Remember, it's running in forced gas mode, so it doesn't want to switch to electric.

[JimChow]

Try this "My RV Works' channel on YouTube. Many helpful videos. You may find your answer here.

https://m.youtube.com/c/MyRVWorksInc/videos

[SmackIt]

Originally Posted by JimChow

Try this "My RV Works' channel on YouTube. Many helpful videos. You may find your answer here.

https://m.youtube.com/c/MyRVWorksInc/videos

I stumbled on that channel a couple weeks ago, a lot of good information. My take away after watching a lot of his videos is that the RV industry, along with Dometic and Norcold, knowingly play a role in the early death of hundreds of thousands of refrigerators. These fridges need air movement. Either put in the necessary fans, or build the compartments with proper airflow.

One item I can't seem to find information on is over cooling. Is it bad to constantly run air over the condenser fins, or does it even matter? When does too much air start to have a negative effect on the system?

[pgandw]

There were some write-up of over-cooling on an Airstream forum a couple of years ago. There is an ideal temp range for the ammonia mix coming out of the heater. And at other points in the cycle. However, instrumenting your fridge to determine if you are meeting that range is more work than I want to do.

I do have some issues with my Dometic 3 cu ft not cooling as well while towing on propane as when dry camping. It's good enough (generally no higher than 41) that I tolerate it without figuring out whether the propane flame is blowing out (not enough heat) and having to restart, or I'm overcooling with the 75mph tow wind. I have no failure codes of any kind.

Fred W
2019 Flagstaff T21TBHW A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

[U.S.ArmyVeteran]

Our previous trailer had a propane/110 vac refrigerator. It was adequate. Not as bad as yours.

Our 2020 Surveyor has a 12 VDC 10 cubic foot Refrigerator. We love it. It cools as well as our big home fridge.

When boondocking it will run from 9 pm to 9 am and not kill our one cheap OEM battery.

Sold!

[hollywood91]

I have a similar model Norcold fridge that came with the same one button control. We replaced it with a new Optical Control board from Amazon. This control board offers 5 temperature settings and was plug and play for our fridge. There is a link below, but know that the price is in Canadian dollars. I'm sure that would be under a $100. from Amazon.com. Over the years we have had better luck with Norcold fridges than with Dometic. Ours has no problems holding 36 to 38 f with ambient outside temps of 80f.

https://www.amazon.ca/Norcold-628979...s%2C284&sr=8-1

[SmackIt]

Originally Posted by U.S.ArmyVeteran

Our previous trailer had a propane/110 vac refrigerator. It was adequate. Not as bad as yours.

Our 2020 Surveyor has a 12 VDC 10 cubic foot Refrigerator. We love it. It cools as well as our big home fridge.

When boondocking it will run from 9 pm to 9 am and not kill our one cheap OEM battery.

Sold!

I was looking forward to the big 12v fridge in my 2021 Surveyor. Specifically remember discussing it with the salesperson. Got the rig home and noticed a few days later I was given the gas/electric. Called up the dealer to complain and got 3 different excuses. First was no inventory due to covid, second was Surveyor had too many problems with the 12v so they stopped installing them, third was that all Surveyors sold west of the Mississippi have gas/electric instead of 12v. The previous fridge in my Jayco never gave me problems, so I just shrugged it off and figured everything would be fine. Really wish I had insisted on the 12v fridge.

[LafIN]

Can you tell me more about the “Secret Modes”. And is this for a norco or is it true for a dometic too. Thanks

[SmackIt]

Originally Posted by LafIN

Can you tell me more about the “Secret Modes”. And is this for a norco or is it true for a dometic too. Thanks

I call them "secret" because they're buried in the service manual (not the owners manual that came with the unit) instead of having a switch or normal user interface one would expect.

Refrigerator Temperature Settings
The user interface (controls) has three (3) temperature settings. The temperature setting can be changed within the temperature set mode of the user interface (controls). To enter the temperature set mode (See Fig. 12):

• Touch and hold the ON / OFF button. The power ON indicator light will go out. Continue to hold the Power ON / OFF button. The power ON indicator light will come on after 20 seconds and go off again after 23 seconds. Continue to hold the Power ON / OFF button. The power ON indicator light will come on again after 30 seconds. Release Power ON / OFF button.

The color of the power ON indicator light shows the current tem- perature setting of the refrigerator:

• Green shows the COLD temperature setting.
• Amber shows the COLDER temperature setting.
• Red shows the COLDEST temperature setting.

Touch and release the Power ON button and the Power ON / indicator light will flash on and off, which indicates that the temperature setting can be changed.

I believe these are specific to the Polar 7 and Polar 8 series of Norcold fridges.

As is typical with Norcold, there's no indication of what the temperature values of COLD/COLDER/COLDEST refer to.

[JimChow]

On the subject of over cooling......our Domectic fridge never worked well in our 2019 TT. It is in the slide and I found out that fridges in the slide don't work as well. So I thought running the fans all the time was the answer. So I installed several fans and by passed the thermostat to have them run all the time. It didn't seem to help on the hot days. The fridge temps would be in the 40's. While camping in September the fridge would freeze everything.
After watching a My RV Works video that Darren did on a fridge that wasn't working well on an expensive rig I kind of copied what he did on our rig. I put the thermostat back in, got better fans, made sure the air was passing through the fins (not around them) and on our recent trip the fridge worked better than before. Granted the outside temps were in the high 70's low 80's but the fridge/slide were in the afternoon sun. The fridge maintained a temp around 37 degrees. I also rotate frozen ice packs from the freezer to the fridge to help.
The real test will be when the outside temps are high 80's/90's.

[SmackIt]

Originally Posted by JimChow

On the subject of over cooling......our Domectic fridge never worked well in our 2019 TT. It is in the slide and I found out that fridges in the slide don't work as well. So I thought running the fans all the time was the answer. So I installed several fans and by passed the thermostat to have them run all the time. It didn't seem to help on the hot days. The fridge temps would be in the 40's. While camping in September the fridge would freeze everything.
After watching a My RV Works video that Darren did on a fridge that wasn't working well on an expensive rig I kind of copied what he did on our rig. I put the thermostat back in, got better fans, made sure the air was passing through the fins (not around them) and on our recent trip the fridge worked better than before. Granted the outside temps were in the high 70's low 80's but the fridge/slide were in the afternoon sun. The fridge maintained a temp around 37 degrees. I also rotate frozen ice packs from the freezer to the fridge to help.
The real test will be when the outside temps are high 80's/90's.

Have you checked the air flow path for the entire cooling system? The Norcold installation manual has pretty strict guidelines for slide based fridges. The number one cause of problems appears to be turbulence which requires a baffle structure to be integrated into a slide based installation. The manual also states that side vented units must have a fan.

After a complete read of the installation manual and a total tear down of my Surveyor fridge compartment, it's obvious Forest River did not read the manual. Every spec shown for clearance around the fridge was ignored.

[Sunseeker16]

My Dometic double door fridge used to struggle so I put it a three fan system. Now even when temps are in the 90s and the rig is closed up sitting in the driveway it will get to 32 or 33 inside. I don't get frost build up on the fins now either.

[pgandw]

Originally Posted by SmackIt

After a complete read of the installation manual and a total tear down of my Surveyor fridge compartment, it's obvious Forest River did not read the manual. Every spec shown for clearance around the fridge was ignored.

Doesn't matter whether the fridge is a Norcold or Dometic - Forest River makes little attempt to comply with the installation instructions. Insulating the sides and top of the fridge, and filling the dead air spaces help. But the real key is getting baffles in the proper place to force the air through the cooling fins, and installing fan(s) to force air through the abominations Dometic calls "vents".

Fred W
2019 Flagstaff T21TBHW A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states on weekend at a time

[SmackIt]

A couple more mysteries I'm unable to locate solid information on.

I'm running the fridge on AC power to try and understand how often the system is running (actually boiling the coolant). My Victron shows the following data for the last 6 hours. This is data from 3-9:00 AM cool early morning temps around 50ºF.



The only thing drawing significant power in the trailer is the fridge at about 300 watts. This pattern seems to indicate the fridge is running about 10-15 minutes, then turns off for 5-10 minutes. Any fridge gurus out there know if this is normal? This seems like a lot of on/off activity to me, however, the fridge is currently empty, so I'm guessing that may have something to do with it.

The second issue I'm puzzled on, is the Norcold Factory Specification for the location of the resistor that attaches to the cooling fins in the fridge? I've found several thousand reference pictures and opinions on the internet, but I can't find an exact statement from Norcold on the proper location.

I found this guide, but can't find info on my N8V model.
https://www.arprv.com/norcold-thermistor.php

[LafIN]

Originally Posted by SmackIt

I call them "secret" because they're buried in the service manual (not the owners manual that came with the unit) instead of having a switch or normal user interface one would expect.

Refrigerator Temperature Settings
The user interface (controls) has three (3) temperature settings. The temperature setting can be changed within the temperature set mode of the user interface (controls). To enter the temperature set mode (See Fig. 12):

• Touch and hold the ON / OFF button. The power ON indicator light will go out. Continue to hold the Power ON / OFF button. The power ON indicator light will come on after 20 seconds and go off again after 23 seconds. Continue to hold the Power ON / OFF button. The power ON indicator light will come on again after 30 seconds. Release Power ON / OFF button.

The color of the power ON indicator light shows the current tem- perature setting of the refrigerator:

• Green shows the COLD temperature setting.
• Amber shows the COLDER temperature setting.
• Red shows the COLDEST temperature setting.

Touch and release the Power ON button and the Power ON / indicator light will flash on and off, which indicates that the temperature setting can be changed.

I believe these are specific to the Polar 7 and Polar 8 series of Norcold fridges.

As is typical with Norcold, there's no indication of what the temperature values of COLD/COLDER/COLDEST refer to.

Thank you!

[JimChow]

Having the baffle to allow the fans to blow air through and over the coils is critical. The My RV Works video stresses that and basically enclosing the area to force the air through the coils.

I forgot to mention that I got rid of the sliding thermistor and replaced it with Snip the Tip adjustable unit.

https://www.snip-the-tip.com/cgi-bin/articca.cgi

[wytravel]

Not sure I understand what you mean by the baffle. Put this inside the access panel on the outside? What would that look like?

Not new to trailer camping at all, but just got a new-to-me trailer and the fridge is having problems cooling. I think it's the thermistor so I'll start there.
I'd like to use the snip-the-tip rheostat but I don't think I'd get it in time before we leave on our trip. If we're having major problems with temperature control then I can order it later and have it sent to our camping location (we'll be there three weeks.)

[pgandw]

The baffle is critical to driving the air through the cooling coils of the fridge instead of around them. You can put all the fans you want on the fridge exhaust but without a properly place baffle, the fans accomplish very little.

Dometic fridge installation instructions contain very detailed measurements of where the baffle should be. These instructions are available on-line from Dometic.

Fred W

[SmackIt]

I'm bumping this thread again in the hopes that someone can answer my question about the power usage of this type of fridge. My unit draws 300 watts when it's running on AC power. I camped at sea level on the Pacific coast highway for 10 days at very mild temps of 50ºF ~ 65ºF most of the time. Is it normal for this type of fridge to constantly draw 300 watts?

What I expect is the fridge to draw 300 watts for a period of time to reach a certain temp. Then it should rest for some time, maybe 20-30 minutes before running again.

[pgandw]

How do you know the fridge is not turning on and off?

Reality is that the AC power consumed goes to power a heating coil - and that's it. Cooling performance of a propane/AC fridge is not quick - the coil has to come up to temp, and supply heat to the ammonia mix. The cooling side must cool the ammonia mix. I would look for cycle time to be much longer than 20-30 minutes, which is more typical of compressor type fridges.

Unless you have an AC power or current meter, there is no way of knowing when the fridge is cycling.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Kia Carnival minivan