I needed to change the air filter on my Bryant furnace so I turned off the power switch (while the furnace was on-I hope that wasn't a mistake), removed the front panels, changed the air filter, put the panels back on, and turned the power back on. The furnace won't turn back on and it's been 24 hours. I've tried checking the panels over and over to make sure they're on properly, I've tried resetting the circuit breaker (it wasn't tripped). I think the power is fine. Is there a reset button or some other obvious step I'm overlooking? Any suggestions?

Model#? Are you certain the panels were re-installed properly? Check for loose or disconnected thermostat wire(s) at the circuit board connections.

Thank you. I had a service man come over and he discovered exactly what you suggested... a wire had become disconnected from the circuit board. But it wasn't a complete waste of a trip... he also installed a new programmable thermostat which should save me money on future bills. Thank you for your help!