Dometic 2193: Amazing on 120v, sucks on propane

rob.mwpropane

Active Member
Aug 11, 2021
367
I'm guessing your fridge is not actually a Dometic RM2193 though? That thermostat knob for the gas is like the one i have, but instead of numbers, it says high, med, low, off

It's not, it's an RM4223.

Does anyone know if the high, medium, low adjust the pilot flame?
 

bupkis

Howdy!
Mar 3, 2006
7,954
N. TX
It's not, it's an RM4223.

Does anyone know if the high, medium, low adjust the pilot flame?
yes, folks know this is not like the control in a household frig!
low is spec'd 293 BTU, high @ 635 BTU (both constant)
a 45 orifice

the 635 btu is more than the 115 watt (120v or 12v) heating element
293 btu is less than 115 watt
 

rob.mwpropane

Active Member
Aug 11, 2021
367
yes, folks know this is not like the control in a household frig!
low is spec'd 293 BTU, high @ 635 BTU (both constant)
a 45 orifice

the 635 btu is more than the 115 watt (120v or 12v) heating element
293 btu is less than 115 watt

The only thing I could find on mine states 1080 btu's with 43 orifice (for the RM4223). That's the equivalent of ~ 316 watts. I can not find anything that correlates the #'s on my dial to any type of btu rating, just the 1080 listed.

If that 635 btu is correct, then he's only getting 58% of the cooling that I can with mine on LP. As you said though, should still be better than 120v.

That's really interesting. You would think the btu's needed for a fridge would be the same for the same size fridge (12v and 120v haven't changed). It makes perfect sense why we prefer LP to 120v though.
 

bupkis

Howdy!
Mar 3, 2006
7,954
N. TX
The only thing I could find on mine states 1080 btu's with 43 orifice (for the RM4223). That's the equivalent of ~ 316 watts. I can not find anything that correlates the #'s on my dial to any type of btu rating, just the 1080 listed.

If that 635 btu is correct, then he's only getting 58% of the cooling that I can with mine on LP. As you said though, should still be better than 120v.

That's really interesting. You would think the btu's needed for a fridge would be the same for the same size fridge (12v and 120v haven't changed). It makes perfect sense why we prefer LP to 120v though.
4223 has a gas thermostat, 125 watt 120v/12v. 1.9 cu ft vs 2.5 cu ft!
 

Arruba

Super Active Member
Nov 28, 2014
866
Central Oregon
To the original poster. Based on your posting that your unit is a 2000 year mode, (I think I read that on your sig line) you don’t mention things like your stove not working, and you know you have propane, I’ll offer the following:

You have cleaned out the burn chamber, can you confirm the pilot is lit?

If the pilot is lit and it’s not getting cold, does your unit have a little bent wire coming from the top of the flue? Can you slide it up and down? That should clear the flue if it’s so equipped. The fridge on my truck camper has it, but to use it I have to pull the unit back towards the service door to slide it. Based on the year of your unit. and it’s getting gas and the pilot lights, I’ll guess the flue is plugged or restricted. I’m with the others, if the fridge doesn’t cool at all on propane, the fan mod isn’t going to fix it.

Good luck and know I feel your pain, these things are frustrating for sure.
 

Sinyk

Member
Jul 8, 2015
88
To the original poster. Based on your posting that your unit is a 2000 year mode, (I think I read that on your sig line) you don’t mention things like your stove not working, and you know you have propane, I’ll offer the following:

You have cleaned out the burn chamber, can you confirm the pilot is lit?

If the pilot is lit and it’s not getting cold, does your unit have a little bent wire coming from the top of the flue? Can you slide it up and down? That should clear the flue if it’s so equipped. The fridge on my truck camper has it, but to use it I have to pull the unit back towards the service door to slide it. Based on the year of your unit. and it’s getting gas and the pilot lights, I’ll guess the flue is plugged or restricted. I’m with the others, if the fridge doesn’t cool at all on propane, the fan mod isn’t going to fix it.

Good luck and know I feel your pain, these things are frustrating for sure.
The furnace works (it gets REALLY hot. I grilled my shin on it in the middle of the night a few weeks ago. My leg looks like a grilled steak... The stove also seems to work fine, though I don't have a good frame of reference for if it's not working up to snuff, but blue flames come out and things get hot. I find it takes a long time to boil water, but that could just be the way it is. I'll have to remove the top cover behind the fridge so i can get a good look in there and see what i can see.
 

Sinyk

Member
Jul 8, 2015
88
OK! I got in there today and cleaned out the burner assembly, jet, flue and baffle. The jet was soaked in 99% alcohol and blown out with air as per the directions. I cleaned out the burner assembly with a stiff pipe cleaner, carb cleaner, alcohol and compressed air. I also wiped down all the pipes and cleaned the fins off as well as took the compressor to all other places to get as much dust out. The flue baffle came out easily, looked clean but i gave it a wipe as well as scrubbed the flue. I didn't see anything that struck me as an obvious issue, but I'm sure a good cleaning can't hurt it.

The fridge assembly


The flame after cleaning (I should have taken a before picture)


The cleaned out flue (You DON'T have to remove the fridge to do this unlike what the manual says.)


Now to let it run and see if there's any difference. When i turned the fridge on, the ambient air temp in the trailer was 90F and the fridge was at 76F.
 

rob.mwpropane

Active Member
Aug 11, 2021
367
OK! I got in there today and cleaned out the burner assembly, jet, flue and baffle. The jet was soaked in 99% alcohol and blown out with air as per the directions. I cleaned out the burner assembly with a stiff pipe cleaner, carb cleaner, alcohol and compressed air. I also wiped down all the pipes and cleaned the fins off as well as took the compressor to all other places to get as much dust out. The flue baffle came out easily, looked clean but i gave it a wipe as well as scrubbed the flue. I didn't see anything that struck me as an obvious issue, but I'm sure a good cleaning can't hurt it.

The fridge assembly


The flame after cleaning (I should have taken a before picture)


The cleaned out flue (You DON'T have to remove the fridge to do this unlike what the manual says.)


Now to let it run and see if there's any difference. When i turned the fridge on, the ambient air temp in the trailer was 90F and the fridge was at 76F.

Thanks for posting pictures.
 

Sinyk

Member
Jul 8, 2015
88
So after about 24 hours, the fridge was reading 54F which was lower than I saw it get before! Unfortunately after another 18 hours, the fridge was reading 65F...

I'm not sure where to go now, maybe get the regulator checked/replaced? How low should I expect it to get?
 

rob.mwpropane

Active Member
Aug 11, 2021
367
So after about 24 hours, the fridge was reading 54F which was lower than I saw it get before! Unfortunately after another 18 hours, the fridge was reading 65F...

I'm not sure where to go now, maybe get the regulator checked/replaced? How low should I expect it to get?

If your reg is working for the other appliances (which I think you said it is?) it's not the reg. Still a slight possibility it's the gas line, but at this point you've cleaned it.. the pilot stays lit, the fridge does cool.. just not all that great.

How much colder than ambient is that 54F and 65F? If it's in the sun and 95F+ outside I don't think they're horrible #'s for a 22 year old fridge. I've read about the fan mod... maybe give that a go? I haven't done it yet... is there any way for you to log ambient temp vs fridge temp and create a graph? And by ambient, I mean what it is at the fins.

Without the above info I'm not sure anyone can give any insight unless they've had the same model... I wish I could help more:(
 

Sinyk

Member
Jul 8, 2015
88
If your reg is working for the other appliances (which I think you said it is?) it's not the reg. Still a slight possibility it's the gas line, but at this point you've cleaned it.. the pilot stays lit, the fridge does cool.. just not all that great.

How much colder than ambient is that 54F and 65F? If it's in the sun and 95F+ outside I don't think they're horrible #'s for a 22 year old fridge. I've read about the fan mod... maybe give that a go? I haven't done it yet... is there any way for you to log ambient temp vs fridge temp and create a graph? And by ambient, I mean what it is at the fins.

Without the above info I'm not sure anyone can give any insight unless they've had the same model... I wish I could help more:(
Using my ThermPro that I use for my smoker since it has 2 probes, I kept one in the fridge and the other outside the fridge but inside the trailer to monitor the ambient temps.

Note that I did not pre-cool the fridge with with 120V this time, this was only propane.
Jul 9th 1:20pm - 76F/88F
Jul 9th 6:18pm - 68F/87F
Jul 9th 8:21pm - 68F/80F
Jul 10th 12:44am - 66F/66F
Jul 10th 8:10am - 54F/67F
Jul 10th 6:10pm - 68F/95F

Note that the fridge side of the trailer is always in the shade (north), but later in the day, the back side of the trailer is in the sun, and i think the probe was in direct sunlight through the window, so the temp of the probe was probably not accurate.

Seeing as I have a half full tank of propane that just expired so i can't refill it along with a boat load of silent PC Fans, i should try out the fan mod. If i can't get the fridge to a reasonable temp with that, i can't see a reason to even run it while i'm boondocking which has been like 19 of the past 20 camping trips
 

rob.mwpropane

Active Member
Aug 11, 2021
367
Using my ThermPro that I use for my smoker since it has 2 probes, I kept one in the fridge and the other outside the fridge but inside the trailer to monitor the ambient temps.

Note that I did not pre-cool the fridge with with 120V this time, this was only propane.
Jul 9th 1:20pm - 76F/88F
Jul 9th 6:18pm - 68F/87F
Jul 9th 8:21pm - 68F/80F
Jul 10th 12:44am - 66F/66F
Jul 10th 8:10am - 54F/67F
Jul 10th 6:10pm - 68F/95F

Note that the fridge side of the trailer is always in the shade (north), but later in the day, the back side of the trailer is in the sun, and i think the probe was in direct sunlight through the window, so the temp of the probe was probably not accurate.

Seeing as I have a half full tank of propane that just expired so i can't refill it along with a boat load of silent PC Fans, i should try out the fan mod. If i can't get the fridge to a reasonable temp with that, i can't see a reason to even run it while i'm boondocking which has been like 19 of the past 20 camping trips

Those are odd #'s.. it's almost like your dial "high, medium, low" is stuck in low or medium... I really don't know.

Can you take a picture of that valve when you get a chance?
 

xxxapache

Super Active Member
Jul 30, 2008
4,558
You need to check your propane flow with a manometer. The pilot can light and have a good looking flame, that still doesn't mean it's getting enough propane. Most regulators can be adjusted, but then again you need a manometer.

I have had to adjust my regulator once or twice over the years. Fortunately my TT has a inline manometer gauge. I can tell the flow to my fridge with a glance.
 

Sinyk

Member
Jul 8, 2015
88
You need to check your propane flow with a manometer. The pilot can light and have a good looking flame, that still doesn't mean it's getting enough propane. Most regulators can be adjusted, but then again you need a manometer.

I have had to adjust my regulator once or twice over the years. Fortunately my TT has a inline manometer gauge. I can tell the flow to my fridge with a glance.
EDIT: I decided to just go straight to a new regulator as they weren't too expensive. At least this will eliminate that as a possibility
 
Last edited:

Anthony Hitchings

Super Active Member
Silver Supporting Member
Mar 2, 2019
3,952
Oakland, California
oh wow, that is awesome, didn't realize! i'll check next time i have it open, thanks so much!
BTW - do NOT take off the fins becasue you will break their bond via the thermal paste which thermally connects the fins to the black coolant tube (its a poor arrangement). If you do remove the fins, I recomment a re-do on thethermal paste - its available online in a big tube.
 

xxxapache

Super Active Member
Jul 30, 2008
4,558
EDIT: I decided to just go straight to a new regulator as they weren't too expensive. At least this will eliminate that as a possibility
Maybe. There's always the slim chance the new regulator is out of adjustment.
 

rob.mwpropane

Active Member
Aug 11, 2021
367
I'll post an update after i have time to install it.
Regulators "should" work out of the box, but not always. I'm not sure where you can find a port, but it's usually 1/4" on the reg itself. We use a u-tube to set them. Just add the #'s on both sides. I shoot for a lockup of 13wc.


If you plan on doing this yourself and need some pointers shoot me a dm and I'd be happy to walk you through it.
 




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