NORCOLD N306 2-way trouble on LP not staying cold

[Coloradokev]

Fridge stays cold on electric. When on LP it gets cold (initial start up, cooling overnight) but through the next day it gets warmer in the fridge (up to 60F). LP has worked fine since camper was new in 2017, (even when traveling)(and up at 8500 Ft elevation) but last season, LP not working good. I cleaned the burner orifice but that didn't seem to make any improvement. (A new burner orifice is discontinued). Exterior vents are clear of and obstructions/debris. I did replace the main LP regulator (auto switch over style for dual LP tanks), located right at the two LP tanks. When double checking gas flow/pressure at the 2-burner gas stove, with both burners lit at same time, both go to high flame (just like normal). Slight "pulsing" of flame height (when on "high"), but this is the same as when new in 2017.
- A web-parts site said to replace thermostat (but isn't the thermostat for electric only??) (and any tutorial on how to do it (if needed to be replaced?)
- another web-parts site said no fridge works well on LP above 5,000 Ft elevation, but my fridge always has works fine (until now)
- Another comment was to replace the (very basic) control board (If a correct suggestion, where can I find a control board for this discontinued fridge?)(and a tutorial?)
- Another comment was to replace the LP pressure regulator in the fridge, but there is NO regulator in the base of the fridge. Main copper gas line comes into base of fridge, connects to aluminum fridge line that goes up to gas control knob (at fridge "dashboard"), then gas line goes down to burner orifice.
Your experienced suggestions are greatly appreciated.
Thanks!

 

[d23haynes57]

The thermostat is active for both LP and propane operation. Check if the fridge has a condenser fan or fans and that they are working. The cooling is needed more for propane due to thar extra heat. In theory it should work better on propane than electric.

 

[Coloradokev]

There never were any fans on this fridge. It worked fine for years on LP, but not anymore.

 

[Coloradokev]

So if it cools fine on Electric, then it's not the thermostat (since thermostat controls both LP and electric)?

 

[TheLooks]

Both methods cool by boiling a mixture of ammonia and water. If the LP is not boiling it as well as the electric is the problem is in the boiler or gas delivery system. Something is interfering with gas flow or clean burn.

 

[Coloradokev]

OK, so reading between the lines - it is not the thermostat?
I'll re-clean the LP burner/orifice.
Could the control board (circuit board) be a problem (lowering flame height) like someone suggested?

 

[Kevin D Pem]

How does the fridge do on propane while still plugged into shore power?

If not on shore power what is the battery voltage when it is not cooling properly.

Do you hear the sparker when you try restarting the fridge?

I first would look for the house battery condition before throwing parts at it.

 

[TheLooks]

It is all or nothing on the flame.

 

[Coloradokev]

I have 1-season-old deep cycle batteries (2 batteries). One reads 12.70V, other 12.72V.
I pre-cool the fridge on electric (shore power) the night before leaving on a trip. Before departure, I switch to LP and camper is plugged into my Jeep's 12V system (house batteries are connected and being charged by the Jeep during travel). Fridge interior temp stays cool (on LP) for several hours and gradually warms to about 60F. The LP flame never goes out, (I can hear the flame through upper vent and feel the heat coming from the upper vent). I have never needed to re-start the LP flame, since flame never goes out. Though, I have not looked at flame height when fridge was at 60F. I have never run the fridge on LP while on shore power. I've always done it this way since the camper was new in 2017. The fridge on LP worked fine for many years.
- the burner orifice hole is so small, it's hard to tell if it's clean since I can't find something small enough in diameter to gently slide through the orifice hole. last cleaning (last season) I used a can of pressurized carb cleaner to squirt through the orifice.
- "Meter - flame indicator" #638632 quit many years ago but never affected LP cooling. Now I just listen for the flame noise and heat to know the flame has lit. The sparker is working

 

[Kevin D Pem]

So if the flame never goes out, your problem is likely the burner assembly.

It is not recommended to clean orfices with anything other than an orfice cleaner. Visit someplace like blue flame and purchase what you need. Make sure the orfice is aligned with the venturi.

Your solenoid may have a blockage.

If the burner is staying lit and the striker is doing it's job, the controller board is not a problem.

 

[Coloradokev]

Original Burner orifice assembly is discontinued. Burner Kit retrofit assembly is discontinued. I have searched online for an orifice cleaner and all I have found is carb jet cleaner or torch tip cleaner. All these are way too big in diameter. The orifice hole in my fridge is very small (not much bigger than a human hair). I'll phone Blue Flame on Monday (but I'm not very optimistic)
Where would the solenoid be located on my fridge - https://www.thetford.com/app/uploads/2024/10/PL_N305N306_637106_20200218-1.pdf

Thank you so much for your help!