Dometic RM2190 fridge won't stay lit

[austinado16]

Popped on the new (and full) propane bottle today and got the burner on the fridge to light, but it won't stay lit for more than a few seconds.  The thermo-couple is working because I could use a BBQ lighter to keep relighting the burner and after a few seconds I didn't have to hold the thermo-couple "button" pushed in any longer, I could just keep relighting the flame.

I pulled off the black air supply chimney and blew through it.  But, it wasn't blocked.

I pulled the sheetmetal housing off from around the burner, took the gas pipe off at the burner's jet.  It wasn't plugged.

The gas pipe from the thermo-couple also wasn't plugged.

With the gas pipe off, I can light the gas coming out of the thermo-couple and it stays lit.  I can put the gas pipe back on and light the gas coming out of the end of the pipe that would normally go into the jet...and it stays lit.  But, hook it back up to the jet on the burner and all I get is a few seconds of blue flame, and the flame sputters and pops itself out.

I've got the trailer parked slightly nose down thinking this would help the gas come "up" out of the burner end.  But the trailer is not level side to side.  Does it need to be perfectly level in order to stay lit?  Or is having it level just a factor in the fridge running and not damaging itself internally with chrystals building up?

Could I have a bad dual pressure regulator?  In other words, I've got enough gas pressure to get gas out of the pipe, but not enough pressure to get past the jet at a volume that will burn once mixed with air the burner?

Any help would be appreciated.

[austinado16]

It works!  Appears the temp control knob isn't as happy as it could be.  Turned it to "max" and finally the burner lit and the flame stayed steady.  Just checked the temp and it's down to about 52*F in the fridge and maybe in the high 30's in the little ice maker portion.  I put a little plastic ice try in it, so we'll see if it'll make ice.

Man, what a relief!  It's been the one thing I was dreading since buying it because I was told the fridge didn't work.

Now I need to hook up the OE heater and t-stat and get that working.

[austinado16]

Been cooking away for about 3hrs, but hasn't made ice yet.  The center "core" of the cooling fins is at 16*F and frosting up a little.  So far, so good.  I have one of those little battery powered RV fans, so I just popped a fresh set of D-cells in that and put it inside.  

Will check it again in a few hours.

[austinado16]

Well, my bubble got burst yesterday when I found the flame out, and it was back to sputtering when I tried to keep it lit.

I gave up on it and found a link to this great refrigerator website http://www.rvmobile.com/ and did a bit of reading last night.

Armed with a much better understanding of the system, I adjusted my regulator on the propane tank, turned the thermostat dial on the fridge to "max" and lit the burner.  It lit pretty easy, the flame is steady and blue, and responds to the thermostat dial being moved to a warmer setting by dimming down to only a pilot light, but still staying lit.  In fact, I used that function to adjust the regulator.  I turned the pressure adjustment screw counter-clockwise until the pilot function didn't work, and then turned the screw clockwise, until it did.  

I'm going to let it run all day now and see if it'll make ice and then I'll see if I can either borrow a manometer or make a simple pressure gauge if I can find a gauge head that'll read down to .6psi (11" of water).

[austinado16]

Well, in just 1-1/2hrs it's cooled down to 45*F.  That's much better than yesterday!  I think I'm getting somewhere.

[AustinBoston]

Armed with a much better understanding of the system, I adjusted my regulator on the propane tank...

...then I'll see if I can either borrow a manometer or make a simple pressure gauge if I can find a gauge head that'll read down to .6psi (11" of water).

If you are not able to confirm the pressure with an accurate gauge, be *very* careful the first time you light your stove.  It is possible to get a clog in the line that an inappropriate pressure increase can overcome.

Also, you're not out of LP, are you?

Austin

[AustinBoston]

Well, in just 1-1/2hrs it's cooled down to 45*F.  That's much better than yesterday!  I think I'm getting somewhere.

If you don't get below 40

[austinado16]

AustinBoston, I appreciate your input.  Trying to learn as much as possible here and bring my self up to speed on these refrigerators, so any help is great!

40*F and the flame is doing great.  On that website in the tech pages he shows some diagrams about how to get better airflow over the coils at back of the fridge......the steel coils, not the aluminum fins inside the fridge.  I looked at my set up, and just as he describes, there's about a 2-1/2" gap between the trailer's wall and the coils.  Plenty of room for the rising airflow to simply bypass the coils completely and go right out the top set of louvers.  So, I cut a 19" x 2-1/2" piece of the 1/8" ceiling board, and screwed it into position under the wood frame just at the top of the bottom access door.  Now all the air that comes in through the bottom door louvers has to go up through the big spiral of metal coils.

I'm at 40*F right now, so we'll see if it continues to drop over the next few hours.

To answer your question:  It's a brand new propane tank, properly purged and filled.

I'm making a manometer right now to test for pressure.  Photos in a while.

[austinado16]

"Houston,we have ice cubes!!!.........over"

[austinado16]

Manometer photo as promised.  Turned out I had the pressure a tad high at about 12.5" water column.  Not bad though considering I was eyeballing it.  Dialed the regulator back to exactly 11".

[austinado16]

Update:  After 23hrs I had low 30's inside the refridgerator on a calibrated thermometer this morning.  So, it appears I've got good cooling.  

I had the thermostat set on "max" the entire time.  After checking the temp, I slowly turned the thermostat down until I heard the flame start to die down.  That put the thermostat at around position #7. But, the flame wouldn't stay lit at the lower setting.

I have a partially clogged thermostat passage.  I've had the little screw with the pilot hole out of the thermostat.  It was clean and looked great.  But I haven't removed the themostat and blown through it (yet).