What can cause this HVAC problem?
Check the thermostat mode, setpoint, and fan setting. If the fan is set to On, it may continue moving air between heating cycles; Auto usually runs the fan during a heat cycle. Check the filter and note whether the furnace starts, runs briefly, then shuts down.
Safe checks homeowners can make
A dirty filter, overheating safety limit, ignition issue, flame-sensing fault, or control problem can interrupt heat. Heat pumps can also feel different from furnaces during normal operation. For a gas smell, leave immediately and call for help from outside. Otherwise, arrange furnace repair or heating repair if the issue persists.
When to arrange professional service
A technician should explain the cause before repairs are approved. If the property uses a heat pump, see heat pump repair. If breakdowns are frequent, compare furnace replacement with repair options. Keep up with HVAC maintenance and use the [homepage](/) to explore other services.
What to ask before approving a repair
Ask the service provider to explain the diagnosis, the work being recommended, the estimate, and any applicable warranty. Share the equipment type and symptoms you observed. Do not attempt electrical, gas, or refrigerant work yourself. Service availability and the work offered should be confirmed directly with the provider.