Norcold Refrigerator Issue

[KenS999]

Hello I have a Norcold model #n306rm8 refrigerator. I use two computer fans to draw air across the coils for more efficient cooling and have a circulation fan inside the refrigerator box. Lately cooling efficiency has been greatly reduced when running in LP mode. The flame meter normally in the middle of the green zone is now way back on the border of the white and green. It is necessary to turn the LP temperature dial to high in order to maintain 38F° in the refrigerator compartment. Every few days I get a large carbon deposit on the thermocouple that sits in the burner flame. Any help on how to correct this issue would be greatly appreciated. Thanks, Ken

[Skip426]

Welcome to iRV2

Sorry your first post is about a problem .

Questions .
How old is the fridge ?
Do you see any yellow powder around the base of the chimney ?
Does it cool properly on electric ?
What color is the flame ? orange/yellow or blue ?

[Fridge Defend]

Originally Posted by KenS999

1) #n306rm8 refrigerator. I use two computer fans to draw air across the coils for more efficient cooling and have a circulation fan inside the refrigerator box.

2) Lately cooling efficiency has been greatly reduced when running in LP mode. The flame meter normally in the middle of the green zone is now way back on the border of the white and green.

3) It is necessary to turn the LP temperature dial to high in order to maintain 38F° in the refrigerator compartment.

4) Every few days I get a large carbon deposit on the thermocouple that sits in the burner flame. Any help on how to correct this issue would be greatly appreciated. Thanks, Ken

1) The computer fans are not optimum, squirrel cage fans (blowers) generally draw less amperage and are quieter. They are better suited for this application because they produce pressure, the computer fans produce very little pressure and will stall with any back pressure such as wind.

2) This all adds up to the fact that your burner is not producing enough heat (more on this), and as counterintuitive as it sounds, the boiler in the cooling unit will over heat due to a lack of ammonia. You should discontinue use until you find the problem, that is unless you have boiler protection on the fridge.

3) By adjusting the temperature, you are just causing the fridge to run longer. Your boiler is not producing enough refrigerant, sooner or later the cycle will stop and the boiler will overheat.

4) This is a good clue, thanks for the input There are a number of things to check, I will list them, not in order, always try the simplest thing first:

a) Did you just fill your propane bottles? Butane has less BTUs than propane, in addition it will soot like you described. Get a refill from another source and see if the issue goes away?

b) Check the propane pressure, if should 11 inches water column (+/-1/2"). Load test, when burners on stove on should maintain the pressure.

c) The propane filter could be plugged, we have instructions on our website on how to clean.

Let us know if this helps?

[TandW]

Pull the burner tip and clean the slots.

[KenS999]

Thank you for all the great input. Refrigerator is 5 years old. Refrigerator runs fine and temp. is more stable on 110. Flame is blue and consistent. No yellow powder around chimney base. Will look into getting a propane pressure test and different fans when I get back to home base. Will also attempt to clean the burner tip. WShall purchase propane from a different source.

So the way I understood it, the burner flame is always on (peizo start) and by adjusting the temperature dial for running on LP, it increases the intensity of the flame. What does the recent change in the flame meter from needle in the solid green to the border of white and green denote? That the flame is not hot enough? Thanks, Ken

[TandW]

Clean the burner tip. It is producing soot because of poor mixing/reduced oxygen environment.

[KenS999]

Originally Posted by TandW

Clean the burner tip. It is producing soot because of poor mixing/reduced oxygen environment.

Will do and thank you for the tip! -Ken

[Old-Biscuit]

Originally Posted by TandW

Clean the burner tip. It is producing soot because of poor mixing/reduced oxygen environment.

EXACTLY^^^^^

Carbon is accumulating due to RICH fuel condition....not enough air mixing with the gas resulting in unburnt fuel

Dirty Burner/Orifice
Clean using alcohol....Do NOT Poe anything thru orifice

See pgs 20 - 22 for info
https://norcold.com/wp-content/uploa...M_N305N306.pdf

[KenS999]

Originally Posted by Old-Biscuit

EXACTLY^^^^^

Carbon is accumulating due to RICH fuel condition....not enough air mixing with the gas resulting in unburnt fuel

Dirty Burner/Orifice
Clean using alcohol....Do NOT Poe anything thru orifice

See pgs 20 - 22 for info
https://norcold.com/wp-content/uploa...M_N305N306.pdf

Okay removed the burner and cleaned burner/orifice with compressed air and alcohol. While it has improved the location of the flame meter needle, the refrigerator box temperature does not seem to budge below 35F when the flame control knob is set on "HI". Outside air temperature is 83° F. And refrigerator side of RV is in the shade.

[Old-Biscuit]

Dirty Flue/Flue Baffle
Low LP System Pressure..........11"WC measured using manometer
Gas Control should measure 16 - 30 milliamps at interrupter terminals\PG 36 in link above

[bentjm]

Originally Posted by KenS999

Okay removed the burner and cleaned burner/orifice with compressed air and alcohol. While it has improved the location of the flame meter needle, the refrigerator box temperature does not seem to budge below 35F when the flame control knob is set on "HI". Outside air temperature is 83° F. And refrigerator side of RV is in the shade.

37 is considered optimal in the refrigerator by most manufacturers.

How cold do you want it to be?

[SteveJ.]

Originally Posted by Old-Biscuit

Dirty Flue/Flue Baffle
...

Highly likely it has some soot up there seein's how soot was being an issue where one could actually see it. Soot can/will interfere with proper cooling.

[Old-Biscuit]

Originally Posted by bentjm

37 is considered optimal in the refrigerator by most manufacturers.

How cold do you want it to be?

On 'HI' and outside temp is only 83*F should be able to cool fridge section down into the low 30's

IF--IF
Flue is clean, LP System is maintaining 11"WC and gas control is functioning properly

[KenS999]

Thank you. Will look into getting the water column test performed and see if I can find a video on how to remove/clean the flu.