Stormin Mormon wrote:
So, how can you get water to leak out of a hot air furnace? Did I
miss something here?



During combustion certain gases form. In high efficiency furnaces, the
burnt gases are routed through a coil, usually stainless steel, that is
mounted to the heat exchanger by a small purge blower. Most of the heat
is extracted from those gases and condensation forms in the coil, which
is usually drained out through a hose or pipe, into a floor drain.
If the coil develops a leak, the condensation leaves the coil through
that breach in the coil instead of being drained out the tube. If water
can escape then so can the cooled combustion gases. Carbon monoxide is
one of those gases. It can make you ill or even kill you in your sleep.

This is as technical as I need to get. If anyone has anything to add,
please do.

Oh, I have 23 1/2 years experience in the hvac field.