Refrigerator & High Altitude

[d-mac1]

I've got a Dometic 2852RBX that works ok most of the time, but when I had it at 9,750' last year it kept going out and wouldn't relight. It would try, but I'd come back after being gone for awhile, or awaken in the morning, and the check light would be on.

My dealer said its the orifice size that needs to be changed for high altitude and said to talk to Dometic technical support. I called and was not happy with the level of 'support' I was provided. Among some curt responses, I was told they aren't guaranteed to run at over 5,000'...NO further help! I live near Denver....EVERYTHING is above 5,000'!!

I continued to try to get some information on what size orifice would make it work at altitude to no avail. Finally the unhelpful phone rep went to ask 'the boss' if it can even be changed on my fridge and when she came back on the phone she told me NO...I can't change the orifice in my unit. I just looked and yes it can be changed. It has a 53 in it now.

Since the problem occurs at high altitude, less air pressure, I'm guessing (if this works like a carburetor) means I need less propane, thus a smaller orifice (or jet if you will).

Does anyone know if I'm on the right track so that I can keep my fridge running next trip up there? If I could get the right sized orifice, my thoughts are to take it along on a trip and if problems, put it in until returning to lower altitude.

In case you are wondering, I was at my dealer because I was guessing the problem was a faulty regulator, but they said thats not the problem if it works fine otherwise.

Thanks.

[JiminDenver]

we pretty much exclusively camp at those altitudes, have a Dometic and it usually runs great unless we do something stupid like overload it.

Here are some you tubes on how to clean the burner assembly up. Not only can spider webs be a issue, I have found eggs in the jets.

Fords RV refrigeration

[ronhanson]

I've had 2 different fridges in different rigs up that high many times. 1 was fine, the other was starved for air at altitude. Opening up the wind shield around the burner to allow more air in solved the issue, no jet change required. It didn't affect operation while on the road either.

[Joe_Way]

d-mac1 wrote:


In case you are wondering, I was at my dealer because I was guessing the problem was a faulty regulator, but they said thats not the problem if it works fine otherwise.

Thanks.

Not sure whether this relates to your problem, but I went through a similar situation a few years ago. Frig would run for varying periods--maybe even a day at a time--then shut down with the CHECK light on. I did all the usual things--clean tubes, clean orifice, blow out bugs and webs. Installed a new Dinosaur control board, but that made no difference. Everything else worked fine--stove, furnace, water heater.

I called Dinosaur tech support to see if maybe I needed a new eyebrow board or ignitor board. After listening to the problem, the tech said his first suspicion was the regulator, and suggested I check the propane pressure with a manometer. I bought one like THIS. Easiest place for me to connect it was at the water heater. I found that the pressure was 7-8 inches depending on how many appliances were running, rather than the correct 11 inches or so. I installed a new regulator and haven't had a problem in 3 years, including trips to our favorite campground at about 6200'.

New regulators are inexpensive enough that I was tempted to just go ahead and replace it without testing the pressure, but I'm a tool guy anyway and wanted to go through the diagnostic process.

One other note--in followup emails, the Dinosaur tech thought the colder temperature at the higher elevation might have been the critical factor rather than the lower ambient air pressure.

[Chris_Bryant]

The Dometic orifice is a laser drilled synthetic gemstone, and the hole is actually rifled, which is supposed to spin the gas to pick up the proper amount of air- this is how they get away with having that big gap between the orifice and burner.
That said, I do not believe that a smaller orifice will get you anything- the same sized burner is used in nearly every model, with the only difference being orifice, and I do not think the smaller models are any better than the large ones at altitude.

That said- I would certainly give the burner a good cleaning and soak the orifice in alcohol and air dry, and if your model uses the integrated ignition board, which doesn't use a thermocouple, I would make sure the electrode is centered over the burner with a 3/16" gap above the burner. A lean flame will be harder to detect, so electrode adjustment is critical.

[d-mac1]

Been thinking about this...I was camped there a couple years ago at virtually the same altitude and I didn't have any problems. Makes me wonder now if perhaps a spider didn't spin a web in the tube leading to the jet....or something like that. Gonna go see and will report back.

The location of our camp was essentially at junction of Taylor River Road and Rocky Brook Road. A couple years ago, we were on east side of RBR...this time a little further west and just slightly higher. I'd be surprised if the difference was even 50'. If it was the jet's size, it wouldn't have worked right previously.

My generator worked great...but the prevailing winds kept blowing the exhaust back onto the trailer and my CO detector kept going off. First time it did that was after I'd tried to go to sleep on 1st night there. It was one thing after another cuz microwave wouldn't work either....a wire got vibrated loose on the drive in. I was going a bit nuts!

[RedRocket204]

d-mac1 wrote:
The dealer said most fridges work at Taylor Park (the 9750 location).

I was wondering if that was the location in question and would agree with what you were told by the dealer. I was at TP last fall, along with the year before, and did not have an issue either time with my fridge while boondocking. However, I don't believe I was at quite the 9750' elevation camping as I was just to the north side of the reservoir. I know that the elevation at the outpost is around 9400' but of course you could get full hook-ups there and run off of electricity... but what a shame to not boodock in that area. Regardless, that difference in elevation is not much and I would expect the same in and around TP.

My small generator was a different story in terms of altitude. I could not even run a coffee maker on the generator, nothing else. My gen is not jetted for high altitude and is only a 2000W gen. The gen definitely showed effects of being at altitude.

For the life of me though, I can't recall the specific fridge I have for a comparison as my TT is in storage right now.

[wgriswold]

My Norcold quit working several years ago and it was because soot had fallen down from the vent and had clogged up the burner. It was obvious when looking at the burner. I cleaned it with a toothbrush and it went back to working. The burner was also worn and I replaced it. An easy job. I don't know if a Dometic is like mine but it is worth a look.

[d-mac1]

I havent tried to clean out the jets. I could remove it to see if its plugged. What else should I try to clean? And I dont know what you mean about seeing at what point burner goes out.

This fridge has no DC option and we're boondocking at that altitude so electric isnt a viable option.

I bought a new regulator last Fall (after the trip) but havent tried it at 9750. Thats kinda part of the struggle...ie...I cant duplicate the problem nor test a fix without hauling it somewhere. The dealer said most fridges work at Taylor Park (the 9750 location).

[Kayteg1]

I did camp at 10k' attitude and drove 12k+ with RV and my refrigerators work just fine. It was "some time" ago so the refrigerators were pilot-type that did not have electronic boards.
But still I don't buy the explanation you've got.
Propane burner is opposite principle to carburetor.
When in carburetor air sucks the fuel and mix ratio is crucial, in burner gas is sucking the air and mix ratio is having pretty loose tolerance.
Did you try to clean everything and see at what point the flame goes out?
Some advanced boards will flash a code.
Since the problem might be just relighting, how about setting the thermostat to lowest and let the burner work 100% duty.

[wgriswold]

I live at 6500' and the local propane distributor knows what jets are needed at altitude. I would call them and see what jets they would recommend at 9000'. I suspect that jets are standard and the ones they sell will probably fit your refrigerator.

I wonder if anyone sells an adjustable regulator that could adjust the propane to a lower pressure when you are at altitude?

[Johno02]

Easiest thing to do might be to run it on electric instead of propane when at that altitude. Of course, that is if you are not there a lot. If you plan on spending much time there, a change might be in order. Remember though, that for proper operation, you might need to change it back at lower altitudes.