A Fix for High-Altitude Dometics on Propane

[msinabottle]

There's a subject that grabs the eye, don't it?

All right--in the Westy manuals, and reproductions thereof, you can read that for operation above 6,000 feet, you need to replace the No. 24 Jet in your Dometic Fridge's propane burner with a No. 22 Jet. Try getting one. I did. People had no idea what I was talking about. And, as an FYI, a replacement No. 24 jet, which I did find, was a mere $74. Winston's fridge goes out at 7,000 feet, and that's where I camp in him all Summer.

Searched and searched... And over the years on the old Vanagon List this solution appeared:

[?Waldo?]

You could run a second propane regulator in the line to the fridge it could be set at any desired pressure, but obviously would only have the ability to lower the pressure below that of the primary regulator. You could also place a single strand of fine multi-strand copper wire into the orifice of the jet. I've done that on carburetor jets with success. My fridge is a bear to light, but stays lit just fine at 7,000 ft. Good info regardless. I don't think I would have thought of a second reg if you hadn't brought up the topic. Cheers.

Andrew

[BigBlueWesty]

Did you ever find a fix for this? I think I may have the same problem. I just got an '87 westy. I tested everything out in the drive way and everything worked great. I even got the fridge running on propane. Went camping for the first time this weekend (at about 8,000 feet). When I got to the camp site I noticed the fridge was out. Tried lighting it again and I could get it lit but it wouldn't stay lit. I could only get it to stay lit if I kept pumping air into it. So it would seem it is not getting enough air flow. Tried it again when I got back home (5,000 feet) and the fridge stays lit with no problem, even made ice cubes! Is it possible to get this thing to work at altitude?

[Rodknock]

I have had success with my stock fridge at altitudes up to 12000 feet. It can be done and you have to have everything in tip top shape. The rubber gasket on the side of the van has to seal completely on both sides, and the screws have to be good and tight (one of mine was stripped so I put a slightly larger screw in there to get it tight). Hi temp gasket sealant is helpful too. The combustion chamber also has to be totally sealed up. Finally, I blow compressed air into the tube below the fridge occasionally and watch all the dust come out the of the vent. It may be hard to get it lit above say 9000 feet, but it will eventually light and stay lit if everything is working perfectly.'

BTW - I don't drive more than a mile or two with the fridge on propane. I put it on battery power when driving. I can't imagine why someone would run it on propane and use up propane when the battery/alternator power is there and free. I keep reading posts from people who want to run it on propane while driving and it baffles me. Perhaps they don't want to go through the hassle of lighting it again?

[MarkWard]

I was recently camping in Colorado at 10K feet. I could light the fridge and it would stay lit as long as I was stationary. It works fine at lower altitudes even underway. I actually posted a question here and had missed this thread. I got some of the same recommendations. It is probably not practical to replace the jet when at altitude.

As far as using the battery when underway. My understanding was that the Dometic on 12 volt was the least effective of the 3 ways to cool.
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[BigBlueWesty]

Thanks for the tips. Have you taken the fridge out before for maintenance? What kind of compressed air are you blowing through the condensation drain? Are you using a compressor or a bike pump? I'm afraid to blow anything to strong through there, but I suspect some dirt or rust flakes are blocking a little airflow and causing my problem. I'll check my flue seal again too.
Thanks!

[Rodknock]

[Rodknock]

More recently I changed the city water hook-up to a vent, but have not tested the effectiveness of this yet....

It may help in really hot weather. I think ideally the vent would be under the fan on the back of the fridge so cool air could be pulled up over the cooling fins. Maybe there is a rubber body plug under there that could be utilized. I sorta recall seeing rubber body plugs under there.

[DLJ]

I personally havent had any trouble with my Dometic at higher altitudes, but will admit that may be a problem for some. I repair and service Dometics and would like to suggest that in order to get a little more air into the burner box unscrew the little cover on the drain tube (bottom of refer) this might allow sufficient oxy to eliminate high altitude trouble. It IS critical for a good flue/exhaust seal to body on the outside. Also next time refer is out, check for small cracks in intake and exhaust . You may also do well to insulate the high tension wire from piezo to electrode. This alone will help starting on propane.
Regarding 12V operation, its the least efficient way to cool, and the saving of propane is very minimal.

[MarkWard]

Good tip about the drain cover. I will certainly try that next year when I get out west. I live at sea level.
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[msinabottle]

Well, for starters, I'd never think of running the Dometic without that drain plug open--propane creates moisture when it burns, and you want that water OUT of the burner box. You do cap that thing at all other times to keep out the multi-legged brigade.

I agree with what every one else said--what worked for me was to give up trying to make a new rubber gasket for the burner box, I used that Form-a-Gasket Copper-based high temperature stuff the last time I pulled the fridge and did much besides, for which see HERE:

http://www.thesamba.com/vw/forum/viewtopic.php?p=6019385&highlight=dometic+sealant#6019385

I checked the vent tubes for leaks and baby-oiled the rubber external gaskets, which seem to like that. Since all the drill in that post, the Fridge has lit at high altitude--that 7,000 feet again--and stayed running while driving below that. What's above is also good advice, but, that's my contribution.

Best!
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'Winston,' '84 1.9 WBX Westy
Vanagon Poet Laureate: "I have suffered in
many ways, but never, never, never in silence."

[BigBlueWesty]

[msinabottle]

[BigBlueWesty]

[Rodknock]

[BigBlueWesty]

I came across this article about flue assembly http://shufti.wordpress.com/2010/08/11/dometic-fridge-flue-assembly/
The author says to caulk the rubber gasket to the side of the van. That seems like a bit overkill. But it got me thinking. When I pulled my gasket off there seemed to be some old residue on the back of it. Were these things originally glued on to the side of the van?

[DLJ]

Regarding the flu seal to outside of van, I repeat, it is very critical. I never use any sealant or caulking, but cant see where this would hurt. If in doubt, seal it. Also the baffle between vent and van must not be bent. If you look, you will see that the baffle and the flue cover are keyed to each other, cant assemble wrong.
FYI the eurovan refrigerator (norcod) is very similar to the Dometic. Early
eurovans came with one outside intake/exhaust vent. Later models came out with their so called, "high altitude model" Two outside vents ! One above the other. Theoretically giving twice the efficiency. This however has not been my experience.

[msinabottle]

The gasket that made the great improvement in how the Dometic stayed burning was the one I made with the Copper Hi-Temp Sealant on two parts of the box around the burner jet itself.

Best!
_________________
'Winston,' '84 1.9 WBX Westy
Vanagon Poet Laureate: "I have suffered in
many ways, but never, never, never in silence."

[BigBlueWesty]

[BigBlueWesty]