Date:         Mon, 31 Aug 2009 21:02:41 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Dometic problems
Comments: To: Mike Miller <mwmiller@CWNET.COM>
In-Reply-To:  <C6C1A8C2.63DA%mwmiller@cwnet.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 07:20 PM 8/31/2009, Mike Miller wrote:
>My dometic has been cleaned, orifice cleaned, chimney blown out, works great
>on the bench.
>
>But at sea level the flame is weak and blows out when driving.

If it blows out then there's an air leak somewhere.  The pilot flame
just barely exists and it stays lit just fine.  Is there other
evidence for the flame being weak?  If the mixture were too lean it
might be more sensitive to going out -- the flame lifts off the
burner and burns in midair, and is a bit noisy.  No idea if you can
hear the noise in that tiny burner.

>  Won't run at
>altitude unless I hold the starting gas button in.

Which doesn't change any flame conditions, just lets gas past the
thermocouple-controlled gas valve.  So the thermocouple isn't getting
hot enough -- wrong position or weak thermocouple or, indeed, a flame problem.

Dometic said that at I-forget thousand feet it could be hard to light
because the mixture was too rich -- solution was to install their
special NLA high-altitude orifice -- or turn the regulator pressure
down an inch or two.  That doesn't seem to be the issue here.

It's possible to burn it on the bench with the flame box open enough
to see the flame.  You have to bend things slightly to rotate the box.

If the flame is lean, or just small (seems to me regular flame is
similar size to a moderate candle flame, not luminous of course) then
I would still suspect the orifice.  A microscope and a back light
will help see the orifice.  If anything physical has been run through
it it could have all sorts of problems.  Alcohol and compressed air only...


  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"