Date: Tue, 13 Sep 2005 19:04:06 -0400
Reply-To: Roger Sisler <rogersisler2000@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Roger Sisler <rogersisler2000@YAHOO.COM>
Subject: Re: Is there a phone number for Dometic refrigerator technical
help?
I have researched the thermistat on the 182b a bit and see that there is a
bypass screw.This screw allows the gas pressure to be reduced to between
1.5 and 3 inches(origionally 11 inches at the regulator and thermistat
entrance).The bypass is for the low setting that will not produce
refrigeration, but will keep the pilot burning on idle. This way the frig
has more than one speed.It has 2. A thinner or fatter replacement screw
will affect this passage as needed by just taking up more or less space in
the passage.I dont think this is my problem as I am getting too much heat
behind the frig at full throttle, using the main gas passage.Another screw
on the thermistat is waaaay inside the housing , but accessable through a
slot on the side. I am trying to figure this one out.I think it tells the
bypass when to kick in or out by turning the knob to max or min.The gas
amount will remain the same for each path as before, but will be timed for
different tempatures , I think.My problem is that max is too much gas. The
burner burns too high a flame and I get little cooling and lots of heat at
the rear fin area.A gas refrig needs an accurate gas pressure . If the
flame is too low, you get no refrigeration(as above), and if it is too high
you also get no refrigeration.When the flame is first turned on at start
up ,with a higher than normal gas pressure ,cooling will occur for a few
minutes till the refrigerant heats up over the correct tempature. Then
cooling stops but heat still continues to rise in the unit.This will
overheat the refrigerant and damage the refrigerator.I think this is what
is happening.The 2 rear computer fans are going about 40 percent of the
time with outside air at 75 degrees.Inside is about 50 degrees at best.The
only possiable solution I can see is that the main path within the
thermistat is too big ,somehow, and allowing too much gas through.I dont
think the bypass screw is to blame.Possiably, the " plate that the push rod
actuates" inside the thermistat is reversed(looks like a coin, but much
smaller).I think the gas pressure at the main passage needs to be reduced
from 11 inches(but to more than 3 inches).There is a gas pressure port on
the thermistat for reading pressure at the thermistat. I do not know if
this reads bypass pressure or main passage pressure.It has a smaller port
opening(about 1/8 inch, as opposed to 3/8 for the regulator test)and I dont
know what type of device is used here to read this pressure. I called
Dometic and have been put on a list to be called back by a tech.As for the
history of the frig,the main orifice at the burner is little used (like
the frige) and clean.I got the frig from a junkyard westy.Lights real easy!
It had never been used as had the westys'stove.Origional plastic wrap still
covered the stove.The gas regulator at the propane tank has been replaced ,
and I adjusted it anyway with a manometer. I called Marshall Gas Controls,
and the tech there says I did it correctly , and that the problem is in the
refrig.Oh boy.Any ideas? Any ideas at all?If I ever get this fixed, it
should run cool. The exhaust vent insulation lets much more heat exit the
van via the round chrome vent.Thanks for the ear, Roger
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