Since you know how to use a multimeter I would suggest measuring the voltage at the 24v transformer. The transformer is located at the furnace. You'll have a primary side, and a secondary side. The 24volts will be on the secondary side.
If you replaced the thermostat without turning the power to the furnace off then you may have either blown a fuse, or the transformer itself. If you have a fuse it will be in series of your 24v wiring. I've seen the fuses located just after the wiring comes out of the transformer, and on the control board.
Please respond with what you decide to do. I would like to hear what you find.
HVAC Technician
EPA issued refrigeration license, College certificate, and 7 years in field.
Kenton,
When you say the furnace, are you referring to the units up in the overhead space (attic) where the handlers/duct work is located, Thanks!
Thank-you...I am plan on trying this tomorrow. I am going to hit "accept" for I feel you have helped. Thanks Again!
Joe