What this usually means
Confirm HEAT mode and a setpoint above room temperature, then check the filter and labeled breaker. Do not bypass panels or safety switches.
A fault light or code visible through a furnace sight glass can help a technician, but avoid opening the cabinet to find it.
What you can safely check
- Thermostat mode and setpoint
- Filter condition
- Furnace breaker and service switch
- Visible fault code without opening panels
When to call a professional
Request service when basic settings and power checks are normal. Leave the building and seek emergency help for suspected gas or carbon monoxide.
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