Homeowner Guide
Cold air from the vents does not always mean the same repair. Start by noting whether the thermostat is actually calling for heat, whether the furnace tries to light, how long the blower runs, and whether there are any smell or breaker warnings.
Confirm the thermostat is set to Heat, not Fan or Cool, and set above the room temperature. Some systems move cool air briefly at startup or after a defrost cycle, but steady cool air while the home keeps losing temperature is a service clue worth writing down.
If the furnace clicks, starts, stops, or blows air without heat, mention whether you hear ignition attempts, see the burner light, or notice the blower running after the furnace shuts down. Those details help separate thermostat settings, airflow restriction, ignition trouble, flame-sensing, limit, heat pump, or control issues.
Leave the area and contact the gas utility or emergency services if you smell gas. Shut the system off and stop resetting breakers if you notice smoke, arcing, a hot electrical smell, burning plastic, or a breaker that trips again. For normal cold-air heating symptoms, request the $95 Springfield Diagnostic. Nearby towns may cost more.
Read the gas smell safety guide