Coby, I think it's at least faintly possible that the boiler got cooked
(i.e. the anticorrosive powder caked and baked on) in the flame area but is
still ok in the electric area.  I'd suggest consulting with the folks at
http://www.rvmobile.com/, they're cooling-unit experts -- they'd know if
this was a possibility.

Please keep us informed on this one, it's a fascinating problem!

david

At 07:42 PM 8/19/2001, Coby Smolens wrote:
>Good suggestion, but... Both Dave and I cleaned the flue, and I inspected it
>with a boroscope (internally lighted fiber-optic device that lets you see
>inside skinny little areas). It's spic and span. Since the flue IS the metal
>being heated and the propane heat source for the boiler tube it's adjacent
>to, it is important it be clean, as you suggest. However, the mystery here
>is that the thing (the ammonia-water boiler tube) that's supposed to be
>heated by the various (12V, 110AC, propane) heat sources IS being heated, to
>about the same temperature in each case - yet while operating on propane the
>cooler never gets past about 25 degrees below ambient, compared with more
>than a 60 degree drop on 110AC. My question is either: What could account
>for the discrepancy beyond the ammonia-water boiler; or, what am I missing
>in my understanding of how this system works?

David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"