Came home today to find my house at 53 F. Thermostat was set at 68, so I checked the breaker and that was fine. Checked the wires from the t-stat to the furnace and everything looked good. Pilot light was lit, so I turned the fan switch to "manual" and now the furnace is blowing cool air. I've never dealt with heating/cooling systems so any advice would be great. Thanks in advance.

Came home today to find my house at 53 F. Thermostat was set at 68, so I checked the breaker and that was fine. Checked the wires from the t-stat to the furnace and everything looked good. Pilot light was lit, so I turned the fan switch to "manual" and now the furnace is blowing cool air. I've never dealt with heating/cooling systems so any advice would be great. Thanks in advance.
Figured it out myself. The cable guy was around my furnace yesterday and must have hit the vent cover and tripped the reset "ring". That's all it was, a little red ring that gave me such a headache in the middle of winter.