Danny,


I went down there and noticed
the door was off.

How did that happen? Who left your furnace open and why?

When I put the door back, the blower just blew incessantly.

Ok, you've got electricity to the furnace. No blown fuses etc.

So I took the door back off, and pressed the white switch that gets
pressed when the blower door is on, and the blower just kept blowing
for as long as I held the switch pushed in.

Back upstairs, teh cover is still off the thermostat, so the thermostat
settings are still at HEAT (versus OFF, COOL) and AUTO (versus FAN ON).

At this point the fan should not be on.

Read section IV of the manual. It explains what should occur and when in
the heating process.
Confirm that you have gas.
Find the furnace switch in your breaker box. Turn it off. Give it a few
minutes. Turn it back on

Dave M.