DIYbanter - View Single Post - Blower motor died on a 18 year old Furnace: Update.

wrote:

You're right. I called them and said what's the alternative to the new
furnace? They said well, you'll be throwing good money after the bad,
but you can replace the blower motor. We'd have to sell you the wheel
as well as those things usually stick to the shaft so much they can't
be removed, and we'll have to inspect the heat exchanger and if we find
cracks we are obliged by law to shut off the heat (you can re-start at
your own risk), yada, yada, yada... The more he talked the more I was
seeing through the thin veil of wanting to sell me the furnace. I may
still need a furnace, mine is 18 years old and may very well be on its
last leg, but I want to be able to make the decision calmly, not under
pressure of "no-heat in the dead of winter". So, if this fix will see
me through this heating season, it will have paid for itself. BTW,
what are the risks of running the furnace with a damaged heat
exchanger? From what I read, the CO is not that much of an issue since
the heat exchanger is under positive pressure from the blower and the
flue gasses just will not escape into the distribution air. Am I wrong
on this?

The other real danger is a house burned to the ground. Because the hx is
under positive pressure a crack tends to cause the flames to roll-out.
Depending upon safeties present or not present, and assuming that they
are well placed and not stuck, you may or may not have concerns. It's
time to think about replacing. Not only are the newer furnaces more
efficient they are much safer. HTH.

hvacrmedic

I understand there is no real good way to check the heat
exchanger, but are there signs of a HUGE problem? Like if I look
inside and see orange flames or something like that. I don't, BTW, I
see nice blue flames that look as they should.

Thanks, guys!
Vladimir