Dometic 2193: Amazing on 120v, sucks on propane

Sinyk

Member
Jul 8, 2015
88
I just got back from another weekend of camping and on this trip, i noticed that my fridge basically failed at its job. I filled it with frozen water bottles before we set off and when we arrived at our site, i fired up the propane. Within the day, the fridge got to between 66-68F where it stayed for the entire weekend.

When I got home, I decided to do some testing on the fridge. I first used my compressor and cleaned out everything really well. I then hooked it up to 120V to see how cold it got. Ambient temp was around 68F. With an empty fridge, it took 1 hour and 39 minutes to get all the way down to 33F. Once it was cold, i turned off the 120V and fired up the propane. after 1 1/2 hours, it was already up to 46F and it kept climbing.

It seems like the propane just isn't cutting it, but I don't know what the problem could be. Thoughts on what could be causing my fridge to suck on propane or what i should do to diagnose/fix it?
 

Jkoht

Active Member
Aug 10, 2020
164
Propane takes anywhere from 12-24 hours to get down to temp. When I run either my popup fridge or my trailer fridge on propane I turn it on the day before I leave to get cold. When I just took my trailer put for 5 days boondocking in warm temps I had to turn the coldness up higher to like 6 rather than 3-4 when it's on 120 v.
 

Sinyk

Member
Jul 8, 2015
88
The propane does not have a thermostat that can be changed. The thermostat is only for 120v operation. I figured after 4 days of running on propane, the temp should have dropped as well as switching from 120v to propane, it should have been able to maintain the temp if everything was already warmed up.
 

bupkis

Howdy!
Mar 3, 2006
7,934
N. TX
They need to be level, enough heat to get the fluid to circulate properly and ventilation.

You've proved propane is not supplying enough heat and/or poor ventilation. Why? low pressure, crap in the burner, unclean, improper install with regard to how close it is to the back wall/added baffle, etc.

Finding the install/maintenance info might be helpful.

folks add baffles and fans to help, some insist propane works the best - not in your case!
 

Sinyk

Member
Jul 8, 2015
88
I found the manual online and I think I'm going to take it one part at a time. I can handle the cleaning of the burner and the burner jet myself. if that doesn't cut it, I'll have to decide if i want to remove the fridge to try and clean the flue tube and baffle. In the mean time, I know a gasfitter who should be able to do a pressure test for me to see if my regulator is the issue.
 

Sinyk

Member
Jul 8, 2015
88
Interesting. Propane in ours can get things cold. Ours does have a thermostat on propane. It's just a little dial from 0-7 I think. I have to keep it on 5 because stuff actually freezes.

I've never even tried 120 before.
in page 9 of the manual, it states "On AC operation, the temperature is controlled by a thermostat. The thermostat knob (D, in FIG. 8) should be set to position 4-5 in normal working conditions." On propane, the knob does nothing to control the temperature, the only thing that does is the gas knob that goes from low to med to high.
 

Dave Fro

Member
Sep 21, 2020
62
Interesting. Propane in ours can get things cold. Ours does have a thermostat on propane. It's just a little dial from 0-7 I think. I have to keep it on 5 because stuff actually freezes.

I've never even tried 120 before.
That actually isn't a thermostat, it just sets the output of the unit, and needs to be raised if it is hot outside. A thermostat controls to a specific temperature, but since there is no temperature sensor, and no modulation of the flame or capacity of the unit, it isn't a thermostat. It is more of a "set it to what you want it to run at, and it will keep running at that" but it will not control to a specific temperature by modulating any of the components of the system.

ah, i see that it does function as a thermostat in 120v mode, but not in propane mode. My model doesn't have a temperature sensor in the actual fridge so mine must be different from yours.
 

rob.mwpropane

Active Member
Aug 11, 2021
367
in page 9 of the manual, it states "On AC operation, the temperature is controlled by a thermostat. The thermostat knob (D, in FIG. 8) should be set to position 4-5 in normal working conditions." On propane, the knob does nothing to control the temperature, the only thing that does is the gas knob that goes from low to med to high.
I'll have to take a picture. I'm pretty sure on mine there are 2 "control panels". 1 is for LP and is located in the lower part. It has a knob with off, pilot, and on. There is also a "thermostat" that's from 0-7 (or maybe 1-7).
That actually isn't a thermostat, it just sets the output of the unit, and needs to be raised if it is hot outside. A thermostat controls to a specific temperature, but since there is no temperature sensor, and no modulation of the flame or capacity of the unit, it isn't a thermostat. It is more of a "set it to what you want it to run at, and it will keep running at that" but it will not control to a specific temperature by modulating any of the components of the system.

ah, i see that it does function as a thermostat in 120v mode, but not in propane mode. My model doesn't have a temperature sensor in the actual fridge so mine must be different from yours.
On the top vent there is another control for 12v / 120v. It also has a "thermostat" that has #'s on it.

I understand 100% that there aren't any sensors to read real temp. I take the knobs to be the same as in a fridge in the house, "cold to colder".

(At least this is how I remember it... but now you have me 2nd guessing my memory which isn't always the best).
 

Sinyk

Member
Jul 8, 2015
88
They need to be level, enough heat to get the fluid to circulate properly and ventilation.

You've proved propane is not supplying enough heat and/or poor ventilation. Why? low pressure, crap in the burner, unclean, improper install with regard to how close it is to the back wall/added baffle, etc.

Finding the install/maintenance info might be helpful.

folks add baffles and fans to help, some insist propane works the best - not in your case!
I looked up that fan mod and the various versions of it here http://bryantrv.com/docs2/docs/dometicventing.pdf. It looks like option 3B is the one i want. I looked inside the fridge compartment and the baffles look like they are already there (the middle one for sure and it looked like there was a curved metal plate behind the fins). I would just need to add some fans to vent out the grill and tap them into the 12v power supply at the back of the fridge. I have a bunch of unused silent PC fans that i could probably string together along the grate.
 

bondebond

Super Active Member
Aug 14, 2008
2,330
The fans, and I set them up on every PUP fridge I've touched, are a bit of a red herring for you at the moment IMO. You've established that the refrigerators works (ammonia evaporation is functioning when proper heat is applied) on 120v AC. If you can get to 33 degrees F on 120v, you're doing WELL.

From what I've read above, you have a problem with propane providing enough heat. Work on the baffles and fans and that whole track AFTER you solve why your propane is not getting hot enough. Clearly, that's just my opinion.
 

rob.mwpropane

Active Member
Aug 11, 2021
367
As promised.
 

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azwildcat

Member
Sep 19, 2021
42
Glendale, AZ
same thing happend to me this last weekend camping, when i switched to propane after i got setup the pilot light would not stay on, pup was level, we carry all of our food in coolers and the frig is only used for some drinks, time for some teardown and cleaning
 

rob.mwpropane

Active Member
Aug 11, 2021
367
I found the manual online and I think I'm going to take it one part at a time. I can handle the cleaning of the burner and the burner jet myself. if that doesn't cut it, I'll have to decide if i want to remove the fridge to try and clean the flue tube and baffle. In the mean time, I know a gasfitter who should be able to do a pressure test for me to see if my regulator is the issue.
I think a good cleaning would take care of your issues. If the other gas appliances are working then it's not a regulator issue. You can always borrow a regulator just to see if that's it.. takes 5 min to change out

The appliances in an rv are a lot like a fireplace. They sit, don't get used, get covered in dust and cobwebs and then when we go to use them they don't work as they should. I tell everyone that has a fireplace use it once a month for a few minutes. Will cut way down on service calls.

Maybe not practical on an rv, but it's either that or tear things apart every few years.
 

rob.mwpropane

Active Member
Aug 11, 2021
367
I will agree that if it works on 110, it should work on propane. I think its in the lines/ tubes or regulater.
I agree with this 100%, although I doubt it's the reg if other appliances are working as they should. You can test it by lighting the cooktop, then light the furnace and watch the cooktop. If the flames look different or even go out then it's stuff in the line or the reg.
 

Anthony Hitchings

Super Active Member
Silver Supporting Member
Mar 2, 2019
3,845
Oakland, California
That actually isn't a thermostat, it just sets the output of the unit, and needs to be raised if it is hot outside. A thermostat controls to a specific temperature, but since there is no temperature sensor, and no modulation of the flame or capacity of the unit, it isn't a thermostat. It is more of a "set it to what you want it to run at, and it will keep running at that" but it will not control to a specific temperature by modulating any of the components of the system.

ah, i see that it does function as a thermostat in 120v mode, but not in propane mode. My model doesn't have a temperature sensor in the actual fridge so mine must be different from yours.
your thermostat probe would be hidden behind the cooling fins at the rear on the inside of the frig, as mine is
 




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