[VAC] Re: hot fridge

["Mr. Joy H. Hansen" <joytbrew@xxxxxxxxxxx>]

  Andrea,

At the risk of getting myself in trouble, I thought I'd share a few thoughts
about "ammonia" refrigerators.  First, you have to forget everything you
thought you knew about home refrigerators, unless  you are older than I (65)
and have some farm living experiences.  Refrigerators were frequently gas
operated when I was young.  I thought I'd see a compressor in my Safari and
I could handle freon, etc.  Not so!  The ammonia refrigerators work slowly
as compared to the house hold types with a compressor.  You might compare
the ammonia refrigerator to a moonshine still (very common in the southern
part of Virginia where I live).  An ammonia/water solution is heated and the
ammonia separates from the water?  The ammonia does the cooling in the
refrigerator.  The outside coils return the water and reabsorb the ammonia
to run back to the bottom of the refrigerator (outside of course).
Sometimes, when the refrigerator is operated off level, the ammonia
crystallizes or something and separates from the aqueous portions that
should
run back to the bottom.  This causes the unit to malfunction.  A fix I read
about involves taking the refrigerator out of the A/S, inverting it several
times, and then firing it up to see if the situation is corrected.
Sometimes works as I've read.  Just keep in mind that the LP flame is very
small and the heat at the top of the stack is hardly above body temperature.
Also, the electric heater runs on 110 volts and can frequently burn out.  A
new heating element is certainly cheaper than a new $1000 plus Dometic.

So, what to do?  Well, I'd take the plug out of the receptacle and measure
the resistance across the hot and negative plug contacts.  I haven't a clue
what the resistance should be, but there should be some and most likely a
lot!  If the resistance is infinite, the electric heater is most likely
burned out.  Just keep in mind that IMHO it's unlikely that both the LP and
EL would burn out or malfunction at the same time.  I can think that the
unit was operated off level and the cooling system is malfunctioning for
that reason.  I read somewhere that the small pipe at the top of the chimney
will have bubbled/burned paint if the unit was operated off level for long
periods.  If the coils are badly rusted, it's also possible that the ammonia
gas has leaked off and that means that the unit is really failed and it's
more likely that you'll need to purchase new.

Finally, keep in mind that these refrigerators are not as fast at initial
cooling as compressor/freon units.  Livingston's RV repair and maintenance
has a great section on  maintenance and trouble shooting these
refrigerators.  Also, there are several web sites that have detailed info on
the operation of these refrigerators.  Meaning that you don't just look for
a fuse problem!

Unfortunately, my Dometic is still sitting on my driveway.  It operates on
both LP and EL; however, the door is so badly broken that the unit is
useless.  I'm still looking for a door from another A/Ser's defunct unit,
but so far I've not had any luck.

If you decide to remove the refrigerator, there's lots of tips for the
project and it will be a huge project.  For starters, the belly pan of my
Safari has two holes with rubber caps to cover the two bolt access ports.
These two bolts are the only hold down other than the sheet metal screw into
the floor from the topside.  My unit only had fasteners on one side.  Other
than that, it's just a lot of screws/rivets, etc. to remove to free the
refrigerator.  Not all that bad, it just takes a lot of time.  For this
reason, I'm of the school that it's better to replace with a new unit unless
the old is in spectacular condition.

I'm still giving a lot of thought  as to why Harvey's refrigerator is
operating
in reverse and heating the interior of the cabinet.  Guess he's supposed to
like hot food while he travels! :)

                                            '69 Safari, Joy