On Mon, 26 Jan 2009 19:35:04 -0500, Bubba
wrote:

On Sun, 25 Jan 2009 20:47:15 -0500, KLS wrote:

Just had the blower motor replaced on our York furnace this morning.
Outside temps were 20F today with some wind. The new motor was
assigned the task of warming the house 45F to 65F. This took it
7 hours, which seems like a long time.

How many degrees per hour is a usual rate of temperature rise for gas
forced-air furnace?

You do know you have asked a trick question?
With the information you have given, it cant be answered.
Here let me give you and example or two so you might understand.
Where I live, we design furnaces to maintain an indoor temp of 70 at a
0 degree outdoor design temp.
What that means is: If my furnace is sized properly and my indoor
temperature is 70 and the outdoor temp is 0, then my furnace will run
24/7 until the outdoor temp begins to raise. If the outdoor temp
continues to drop to -10 or -20 below 0 then my house will begin to
get colder and colder and I will need to add some type of supplemental
heat.
On the other hand, with that same furnace, if it is 50 degrees outside
and 60 degrees in my home and I want to raise it to 70 I would
probably take much less than an hour.
What you are interested in is if the motor replacement you just got is
set properly. It should be set so that you get the proper "temperature
rise through your furnace as stated on the furnace equipment label.
Usually a temp in the range of 35 - 70 degrees.
More blower speed will lower this temp range. Less blower speed will
raise this temp range.
Bubba
Only problem, bubba, is he didn't evenask the right question - it
wasn't the blower fan motoer that was replaced. It's the cumbustion
purge blower, or eductor fan.