Dometic Fridge not cooling properly on LP mode

[billyray50]

Recently my Dometic fridge model DMR 702 has not been cooling at the same temps as on AC mode. It was manufactured in 2013 for 2014. AC mode the fridge temp is between 36 and 38 degrees. Freezer at 0 degrees. On LP fridge temps are around for 47 with high reading at 53 later in day. Daytime temps have been averaging between 79 to 82 degrees with average humidity here in upstate New York.






Things I did was to check the fridge pilot, burner assembly, and 12 volt fan. All seemed to be working fine.

[ernie1]

Thanks Doug I'll just go out and buy a new regulator and be done with it. It was probably the source of my original problem to begin with.

[dougrainer]

ernie1 wrote:
dougrainer:
Is the 11 1/2" you're referring to at sea level? I was at 7,000 ft elevation and only had about 5" and the refer didn't want to light. Rv tech set the pressure to 16" and said at sea level it should be okay. What do you think?

I think you have a dangerous set up. You never change the LP pressure and never go higher than 12 inches. You either change the LP appliance orifice jet or do other modifications if needed but never change the LP pressure. BTW, most LP ranges/Stoves have their own internal LP regulator set at 10 inches. They run at 10 inches not 11.5. Doug

[billyray50]

Thanks for tips. I drove truck/TC for over 4 hours yesterday watching Grandson's baseball game and doing errands. Checked thermostat in freezer and is was reading zero degrees. Going to pick another thermostat for fridge but everything was real cold. More ventilation while driving? Will clean the burner assembly for sure. Did a leak test on all propane connections a week ago and no apparent leaks but will leak test the regulator again.

[ernie1]

dougrainer:
Is the 11 1/2" you're referring to at sea level? I was at 7,000 ft elevation and only had about 5" and the refer didn't want to light. Rv tech set the pressure to 16" and said at sea level it should be okay. What do you think?

[32_Chev]

A friend of mine had the exact same problem Clean the burner slots . The frigd will cool much better and the propane smell will go away.

[enblethen]

OPs refer is in a slide. He is going to have a difficult time pulling the baffle out without bending the hell out of the support wire.

[stickdog]

SidecarFlip wrote:
Forgot to add (getting old and forgetful), when you remove the top outside cover, look at the top of the boiler stack and you'll see a wire sticking up, clipped into a sheet metal securing clip. Pop it out and pull the baffle out and put it back in and pull it out..couple times.

Then clean the carbon off the baffle and vacuum up all the carbon and **** that has fallen from the tube the baffle is in. You need the chamber clean for the burner to heat the boiler properly and they all get carboned up after a while.

Working better on 110 than propane tells me the chimney tube is carboned up. Propane runs hotter than the 110 volt heating element, but the element is in next to the boiler tube and protected from the flame.

I agree.

[Old-Biscuit]

YOUR picture of propane flame.....





Picture of a properly burning fridge propane flame





YOUR flame is anemic.....
either blocked burner slots
OR
low propane system pressure



LP Regs have vents.......
1st stage has a small pin hole vent and 2nd stage has a larger screened vent.
Both vents allow 'air' to move in/out of top of diaphragm as diaphragm moves to control pressure/flow.
Should be NO propane coming out of either vent unless diaphragm is torn/cracked.
Simple 'bubble' check....spray bottle full of water with several drops of liquid dish soap.

Should not be any bubbles are either vent or crimped body of reg.

Reg if not leaking may need adjustment.

Remove and clean burner and also remove clean orifice (soak it in alcohol then blow out with LOW pressure air)

[red31]

Betting on low propane pressure.

No, it should not smell from adjusting to ambient temperature, it is sealed. The vent is to allow the diaphragm to move freely.

[billyray50]

Thanks for all the advice. Will look into extra fans, extra insulation, sheet metal baffle. I will also check the spiral baffle, saw it earlier but did not remove it yet to clean.

[SidecarFlip]

Forgot to add (getting old and forgetful), when you remove the top outside cover, look at the top of the boiler stack and you'll see a wire sticking up, clipped into a sheet metal securing clip. Pop it out and pull the baffle out and put it back in and pull it out..couple times.

Then clean the carbon off the baffle and vacuum up all the carbon and **** that has fallen from the tube the baffle is in. You need the chamber clean for the burner to heat the boiler properly and they all get carboned up after a while.

Working better on 110 than propane tells me the chimney tube is carboned up. Propane runs hotter than the 110 volt heating element, but the element is in next to the boiler tube and protected from the flame.

[SidecarFlip]

I get the odorant smell in my compartment as well. Not a worry. It's the regulator adjusting to ambient temp. I passes very little.

[SidecarFlip]

One wimpy fan is marginal at best. Add another or buy 2 new ones (cheap on Flea Bay) and move them to the upper cavity right in front of the condenser 9on the top of the tubing) blowing out the upper vent panel and optionally, a curved aluminum sheet baffle fitted behind the condenser fastened to the inner-outer framing (Suburban supples that baffle or you can make your own). That will solve your warm fridge issue. In reality, the only place you need to artifically transfer heat is the condenser at the top. The tubing is inconsequential.

You still need to practice efficient cooling essentials, like parking where the afternoon sun isn't on the fridge side.

You already have one thermostatically controled fan so the thermodisc and wiring is already in place. Just move the fan(s) to the upper cavity blowing out and you'll be good.

Additionally, check the insulation between the fridge and the outer cabinet as well and add additional insulation if needed (probably is). R12 unfaced insulation is cheap. Stuff the space all around the fridge full

[dougrainer]

Level not a concern if it cools correctly on 120. Ventilation not a concern also if it works on 120. IF the burner and flue are clean, the LP Gas PRESSURE needs checked AT the refer. Slightly lower than 11.5 inches pressure can have dramatic affect on LP cooling performance. Doug

[DaveG39]

check chimney stack and baffle inside chimney for carbon plugging. Check the cooling fans to make sure they are working.