RM 2454 Problem Heading into SE Colorado Boondocking

[Geronimo John]

June and I are wrapping up a family wedding week in Denver.  Next we will be heading out to the high country for some boondocking.  Will for sure need our Dometic RM 2454 refrigerator for a couple of weeks.  Could use some guidance:   

WHAT I THINK I KNOW

o   Refrigerator works normally on 12 Volt power supply.

o   Refrigerator works normally on 120 Volt .

o   Refrigerator does not work on propane regardless of outside temperature.  It seems to hover a bit above 60 degrees in the main area of the unit when using gas mode.  Likely about what ambient has been inside our Ollie due to nighttime cooling temps.

WHAT I HAVE OBSERVED

o   The thermistor that activates cooling is operating normally only when using 120 and 12 Volt power.

o   Control board appears to be operating normally for all power sources though.

o   When switched to gas, the Control Board is trying to strike.  Sends three strikes and then seems happy. 

o   The striker appears to be igniting a dribble of gas at the propane orifice, however, it is less than 5% of what is necessary for heating the absorption unit. 

ANALYSIS:   Leads me to believe that I have a gas problem.  Ok, I set myself up for that one......  Thinking it is likely either:

o   A 95% plugged gas orifice.

o   A defective gas control valve.

o    A safety thermistor that would shut off gas flow if no flame is sensed. 

INVESTIGATE:  Thinking I should:

o   Pull the gas orifice and see if clear.  If contaminated, clean in a non-destructive manner.

o   Pull the gas tube after the orifice to see if any issues there.

o   Test the gas control valve and mother board:  .  Is it possible to spoof the main control valve with voltage to determine if it’s operational?  If yes, what voltage should I see from the mother board?  Can I spoof it to see if it is functional or if the mother board is weak?

o   Remove gas tube downstream of orifice and look for mud daubers or other such inclusions. 

o   Does the igniter/striker also act as a safety to shut off gas flow if the strike process is not successful?  If not how is that safety feature accomplised?

Any thoughts, suggestions, recommendations or part numbers would be greatly appreciated.

Thanks,

Geronimo John

[Steph and Dud B]

Sounds like altitude to me. Gas appliances often need a different orifice to work at higher altitudes. You might be able to get a high altitude one at a local RV repair shop.

[jd1923]

1 minute ago, Steph and Dud B said:

Sounds like altitude to me. Gas appliances often need a different orifice to work at higher altitudes. You might be able to get a high altitude one at a local RV repair shop.

I believe we have the same model Dometic fridge. Ours has worked fine several times camping in CO outside of Telluride and on the White Mountains in AZ, both above 9K ft. Also, it reads like GJ is still in Denver just over 5K ft.

GJ, you're getting the 3 clicks, so all electrical controls are fine. You certainly have a gas issue. I have no experience there but believe your "analysis and investigate" lists are right on. Best wishes, JD

[Geronimo John]

JD:

Correct on both.  Still in Denver and it always works perfectly for months up at King Mountain where we basecamp at 5,300.  I think that well over that elevation we would need the other smaller orifice to reduce gas flow due to lack of O2 higher up.  Not the case with ours in Denver now.  Currently, we don't get anywhere near the gas flow to even heat the ammonia hot enough to flash to cool.

Hopefully one of the owners can respond with info about the gas valve voltage and possible test procedure for it.  It's a long shot, but worth a try.

I have heard others have had mother board issues, but never heard of the refer gas valve going south.  

Along the gas thread:

I'm also wondering if there is a screen that keeps trash from tank insides or junk from bad propane that could clog or plug the oriface?  If so, where would it be located?

GJ

Edited 25 minutes ago by Geronimo John

[Townesw]

@Geronimo Johnsee if you can find any answers in this service manual

 

https://fourwheelcampers.com/NewDometicRefrigeratorManual.pdf

 

I had trouble getting my RM2454 to cool in Ashland VA last week after working fine for 3 weeks. It was just too hot there at 97F for the absorption cycle to work well. I temporarily added a double bladed window fan from Lowes. Still wouldn’t work even at night. Turns out that too much air movement is as bad as not enough. I turned the temporary fan off and the refrigerator started working again. 
 

Bill

Edited 11 minutes ago by Townesw

[Geronimo John]

6 minutes ago, Townesw said:

in this service manual

GOLDEN!  Many Thanks!

Will digest it this afternoon.  

🙂

GJ

Owners:  Suggest saving this document if you have an older frig.