To fix an HVAC system that isn’t blowing hot air, start with basic checks: confirm the thermostat is set to Heat and a higher temperature, the air filter is clean, and power to the furnace or air handler is on. The most common cause is an incorrect thermostat mode or a clogged filter that restricts airflow and can shut equipment down. If the blower runs but air stays cool, ignition or safety sensors may be keeping the burner off; our technicians often find a dirty flame sensor after long gaps between tune-ups. We handle this problem routinely for families throughout Central Indiana, including homes near Zionsville. Our certified technicians arrive in fully stocked trucks, so most repairs can be completed on the same visit, with honest, upfront pricing with no surprise fees.
Try these simple steps before calling:
- Set thermostat to Heat and fan to Auto; replace batteries if needed.
- Replace a dirty filter; make sure vents and returns are open.
- Check the furnace switch and breaker; verify the gas valve is on.
- For heat pumps, clear snow/debris from the outdoor unit.
If you smell gas, turn the system off and call a licensed pro immediately.
Updated: 2026-06-25
Need help in Zionsville, IN? Call 317-830-5862 or book online.