I replaced my thermostat with a new one in November. The furnace worked fine all winter and when spring rolled around my husband flipped the switch on the furnace to off. Now that it's so freaking hot, candles are melting, I turned the switch to cool and the fan to auto and NOTHING. I did go downstairs and flip the switch back on. The furnace does not come on, the blower does not come on, no heat or cool air... Nothing. Like it's not plugged in. :rolleyes: Does anyone have any suggestions?

Check your 24 volt power transformer with a volt meter and all low voltage wiring. There could also be a small fuse on the circuit board in the furnace if so equipped.