A/C (Fan) Working but Heat Not Turning On
I have a Honeywell thermostat that was included with my home when it was built in 2006. Today I went to turn my heat on and noticed it did not turn on no matter how high I set the temperature. I have noticed a slight rattling come from the vent downstairs when the air or heat is on but didn't pay attention to it. I thought this might be the cause and that some wires may have shorted, but when I turned on the fan it worked fine (still with the same rattling). Any idea why my heater is not turning on?