Dometic 2193 Fridge not cooling on propane

grrrrraham

Member
Apr 9, 2018
30
Hey all,

the fridge in our PUP is acting up. It works great on 120v and 12v. Switching over to LP and it just doesn’t cool at all. In fact it almost feels warm in there.

The burner has no problem lighting and stays lit. It’s a nice blue flame even at low setting.

the stack/chimney cowl gets nice and hot. But there is just no cooling happening at all.

any ideas? Is this something I can fix with basic tools/parts on the road?

thanks!
 

xxxapache

Super Active Member
Jul 30, 2008
4,558
You also need to check your propane pressure with a manometer. You cant judge it by looking at the flame. If your propane pressure is low, you can adjust the regulator.

I have had propane cooling problems in the past due to low pressure. Fortunately my TT has a built in manometer. Adjusting my regulator was simple because of it. It corrected the problem .
 

grrrrraham

Member
Apr 9, 2018
30
You also need to check your propane pressure with a manometer. You cant judge it by looking at the flame. If your propane pressure is low, you can adjust the regulator.

I have had propane cooling problems in the past due to low pressure. Fortunately my TT has a built in manometer. Adjusting my regulator was simple because of it. It corrected the problem .

Thanks for the reply. This is promising. I just need to find a manometer to confirm before I do more intense work. Cheers!
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
well, for me it did. In my case the hardest part was breaking loose the flare nut on the gas connection , it did not want to budge.
Can you go into a little more detail as to what exactly you came across and how you fixed it? I have the exact same problem as the OP here. We just got back from 3 weeks of camping. Part of the time we were on a non electric site. The fridge worked good for about the first 3-4 days on propane, then performance quickly went downhill. I thought the fridge crapped out, but all the lines were warm, which made me think that the sealed system was still fine. It worked fine at home before we left, and worked great on propane at a rally we went to a few weeks before. So we then moved over to an electric site for the remainder of our stay, I plugged the fridge into 120v just to try it, and bingo, it works great. There was plenty of propane in the tank, and I will guess that gas pressure is good coming from the regulator because the stove and the bbq both run great. The flame for the fridge seems to be as I remember it looking during other times, but it seems as though there isn't quite as much heat coming out of the upper vent as I remember. That might point to your diagnosis.

I figured that possibly an orifice or something may be getting plugged in there that I could clean out, but you're saying the chimney may have a problem. What did the inside of your chimney look like when it was plugged? What did you have to do to yours to clean it all out? You say you had to remove the fridge.
 

Anthony Hitchings

Super Active Member
Silver Supporting Member
Mar 2, 2019
3,945
Oakland, California
the entire cubicle holding the fridge had small wasp nests here and there, including some between fridge wall and cubicle wall.

and when I completely removed the frig in order to clean burner and chimney lo and behold there was a charred wasp nest inside the lower boiler chimney blocking 95% of the chimney cross section.

as part of the fix we glue gunned bug screen on the inside face of the two exterior plastic grilles. Now this bug screen also impedes convection air flow, so the bug screen fix needs to be accompanied by one or two 12v fans to move air across the frigs’ cooling fins.
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
the entire cubicle holding the fridge had small wasp nests here and there, including some between fridge wall and cubicle wall.

and when I completely removed the frig in order to clean burner and chimney lo and behold there was a charred wasp nest inside the lower boiler chimney blocking 95% of the chimney cross section.

as part of the fix we glue gunned bug screen on the inside face of the two exterior plastic grilles. Now this bug screen also impedes convection air flow, so the bug screen fix needs to be accompanied by one or two 12v fans to move air across the frigs’ cooling fins.
Ok, thanks. So then this may or may not be my problem. I have fridge fan and bug screening on my vents for years now. Thanks anyway, I'll keep looking for an answer.
 

A-Ranger12

Active Member
Feb 25, 2020
264
Western NY
Could be a spider set up a nest inside the burner. That would block the propane flow enough for it not to cool, but make a flame. Had that occur.

I was able to access the chimney from the side of my camper, and clean it with a long wire handled brush. That helped a bit.
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
Thanks, I watched a few Youtube videos on the problem and a lot of them are saying to clean the jet for exactly the 'too small of flame' problem. As you say, possibly a spider went in there and set up house. We are headed out in a few days, and I don't have time to get at it before then, but it won't matter this time, we're just doing a short stay at an electrical site. I'll get into it more when we get back. Thanks
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
So, as far as I can tell, I've got this thing fixed. I decided to take an hour and clean the jet. I took off the tin cover in front of the flame, and had a good look at the flame. It looked pretty good to me. It was good and solid, and very blue, no orange. It seemed to be burning with a certain amount of force, but I figured that I'd clean the jet anyway. I took the long rectangular piece that holds the jet and the burner out to give it all a good cleaning. The jet is mid way along inside the long rectangular piece. When you disconnect and unscrew the propane line, the jet will fall out of where the line was screwed into. I cleaned the jet with some carburetor cleaner and blew it out with compressed air. I took a piece of wire, it was a single strand from a piece of speaker wire, and I gently ran it through the hole in the jet. The wire was very loose inside the hole, so I wasn't afraid that I was enlargening that hole by mistake. Honestly, the jet looked fine and clean before hand, but whatever. I then took the long rectangular piece to the wire brush on the bench grinder and gently cleaned all the rust and corrosion off the outside and in around the burner assembly. I used a variety of small scrapers to get inside where the jet sits and scraped it clean as well. It all then got sprayed with carb cleaner and blown clean with air. Compressed air went up and down the chimney and throughout the whole area in general. It all went back together and got re-lit. I took before and after videos of the flame burning, and I honestly don't see much, if anything of a difference. The flame might be a bit bigger, but not much. I gave it a day, and the fridge is back to its normal self, super cold. So there it is, it seems to be working. Maybe there was a spider's nest in the chimney, who knows? Interesting to note that when turning the knob from low to medium to high on the gas valve, if you look closely, you can actually see the flame vary in size. I wasn't sure if it actually did that, but it does.
 

grrrrraham

Member
Apr 9, 2018
30
So, as far as I can tell, I've got this thing fixed. I decided to take an hour and clean the jet. I took off the tin cover in front of the flame, and had a good look at the flame. It looked pretty good to me. It was good and solid, and very blue, no orange. It seemed to be burning with a certain amount of force, but I figured that I'd clean the jet anyway. I took the long rectangular piece that holds the jet and the burner out to give it all a good cleaning. The jet is mid way along inside the long rectangular piece. When you disconnect and unscrew the propane line, the jet will fall out of where the line was screwed into. I cleaned the jet with some carburetor cleaner and blew it out with compressed air. I took a piece of wire, it was a single strand from a piece of speaker wire, and I gently ran it through the hole in the jet. The wire was very loose inside the hole, so I wasn't afraid that I was enlargening that hole by mistake. Honestly, the jet looked fine and clean before hand, but whatever. I then took the long rectangular piece to the wire brush on the bench grinder and gently cleaned all the rust and corrosion off the outside and in around the burner assembly. I used a variety of small scrapers to get inside where the jet sits and scraped it clean as well. It all then got sprayed with carb cleaner and blown clean with air. Compressed air went up and down the chimney and throughout the whole area in general. It all went back together and got re-lit. I took before and after videos of the flame burning, and I honestly don't see much, if anything of a difference. The flame might be a bit bigger, but not much. I gave it a day, and the fridge is back to its normal self, super cold. So there it is, it seems to be working. Maybe there was a spider's nest in the chimney, who knows? Interesting to note that when turning the knob from low to medium to high on the gas valve, if you look closely, you can actually see the flame vary in size. I wasn't sure if it actually did that, but it does.
Awesome stuff... great to hear! I will try this. Did you take the fridge out or did you manage to blow compressed air up the chimney while it was mounted?
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
Awesome stuff... great to hear! I will try this. Did you take the fridge out or did you manage to blow compressed air up the chimney while it was mounted?
I didn't remove the fridge. I also didn't remove the chimney. Take both upper and lower outside vents off the Pup body and you have plenty of room to work on this stuff. With the burner assembly removed from the bottom of the chimney, and the upper outer vent removed, its very easy to blow air up and down the chimney to clear out any debris. I also removed a small angled metal diverter at the top of the chimney pipe to make it easier to blow air down. It's only a single screw to remove it.

thanks for the follow up
You're welcome. I usually try to do this to wrap things up for future readers. There's nothing like going on a car repair forum with a problem, find a thread on there that is the same problem as you're having, have a bunch of ideas on what the fix is, and then the thread stops dead and leaves you hanging. Then you can't even jump in on it because the thread is 6 years old and none of the posters have been back on for 4 years. Very frustrating.
 

grrrrraham

Member
Apr 9, 2018
30
Bet your chimney is blocked internally, as mine was. The ammonia cycle is fine else the other two modes would not work.
Alright, so I spent most of this morning on this. I ended up pulling the fridge out and managed to get all the pieces to get a good look.

From what I could tell the chimney had no blockages. The baffle was fine. The burner jet *looked* clean but I followed the install guide's directions to soak it in alcohol and blow air through it. The burner assembly was fiarly clean as well, just some rust and a small coating of soot which I rubbed off.

Anyway, got it all re-assembled and I think the flame might be a bit bigger than before but hard to say. Either way after 8 hours or so, the fridge is barely cold. There's something there but it's definitely not enough to keep milk from going bad.

Here's where I'm confused. After 8 hours of running on high, the chimney tube is hot, the top of the fridge is warm (feeling the cabinet above it), the tube running along the top with the fins is hot. So I can only assume the propane is doing the job it needs to do.

However, the thick black tubes and black reservoir near the bottom do not get appreciably warm. Should they be? Is there potentially a blockage in heat transfer from the top tubes to the bottom tubes? Seems odd though because I would assume these tubes work the same on 120v which cools just fine.

Anyway would love any more insight. Thanks all.
 

Wrenchgear

5 Star Eagle Camper
Aug 5, 2010
3,694
Near Elmira, Southern Ontario
At this time, I don't have my fridge tuned on, so I can't answer your question as to how warm/hot the lower tubes and the black reservoir get. I don't think they get too hot, just really warm, certainly not uncomfortable to the touch. How is the temp in the fridge this morning now that it has a few more hours of running time on it? The black fins on that upper pipe are obviously for removing heat from that pipe. Any way that you can create air currents around those fins is beneficial to cooling the pipe. A lot of people (including me) have installed an old 12v computer fan at those fins to help draw air across the fins and remove that heat. If you haven't done that mod, I highly recommend you doing that, it made a world of difference to my fridge. In my case, the fridge cools down in half the time as before, and also gets much colder. I also have a small battery operated fan inside the fridge cabinet to move air around in there. That not only helps push the cold air around and in between the contents, but also helps to move air across the cooling fins inside the fridge. You'll feel the metal racks in there getting cooler faster.
 
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xxxapache

Super Active Member
Jul 30, 2008
4,558
Once again....If your fridge is cooling on propane but not enough, you need to check the gas flow with a manometer. Just looking at the flame isnt enough. Your regulator may need to be adjusted or replaced.
 
Last edited:

grrrrraham

Member
Apr 9, 2018
30
Once again....If your fridge is cooling on propane but not enough, you need to check the gas flow with a manometer. Just looking at the flame isnt enough. Your regulator may need to be adjusted or replaced.
Sorry totally forgot to include in my last post that I did verify gas pressure. I'm hoping I did it correctly: there was a port under the fridge gas control that had a nut on it. I unscrewed the nut, put my manometer on and turned the gas on to high and it was reading just over 12 inches. I adjusted the regulator and brought it down to 11 inches.
 

grrrrraham

Member
Apr 9, 2018
30
At this time, I don't have my fridge tuned on, so I can't answer your question as to how warm/hot the lower tubes and the black reservoir get. I don't think they get too hot, just really warm, certainly not uncomfortable to the touch. How is the temp in the fridge this morning now that it has a few more hours of running time on it? The black fins on that upper pipe are obviously for removing heat from that pipe. Any way that you can create air currents around those fins is beneficial to cooling the pipe. A lot of people (including me) have installed an old 12v computer fan at those fins to help draw air across the fins and remove that heat. If you haven't done that mod, I highly recommend you doing that, it made a world of difference to my fridge. In my case, the fridge cools down in half the time as before, and also gets much colder. I also have a small battery operated fan inside the fridge cabinet to move air around in there. That not only helps push the cold air around and in between the contents, but also helps to move air across the cooling fins inside the fridge. You'll feel the metal racks in there getting cooler faster.
OK thanks for that suggestion. Here's one more question: I assume those fins have the same purpose and effect as when on 120v? If they get enough airflow on 120v to cool adequately would it make a difference if that same airflow was also available on propane or would make sense that it would need more flow on propane?
 




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