My bet is that the heat exchanger has rusted through. In any case I
would not use that furnace again. Replacements are cheap insurance
againts killing all inside that toy hauler.

Tom J

Sounds like time for a thorough inspection of the furnace. You possibly have
a hole in the firebox allowing the carbon monoxide to enter the air handler.

Leanne

Since it is a toyhauler, I assume you start up your ATV/motorcycle
inside to move them in and out. I believe CO detectors accumulate the
amount of CO that HAS been present. If this is so, you'll need a new
detector.

I would get someone from the fire dept. to check the CO level while the
furnace is running with their meters. This will tell you if you need
the furnace checked or just replace the CO detector. They usually will
do it for free.

Also, I would purchase a new meter anyway since they are usually under
$20.

Hank <~~~thinks safety

Well I took the furnace apart and found that something had set up home inside
of the fan. I cleaned ot out and ran air through the whole furnace and set it
back into place. I then ranthe furnace for an hour or so and no alarm so I am
hoping that this will take care of the problem. I am definitely considering a
new alarm unit just in case.
Would the nest build up cause the problem?