Fall Furnace Inspection Checklist
Fall is the right time to inspect and service your furnace before cold weather arrives. Furnace problems that go undetected in fall turn into emergency calls in January. Here is what to check and what to have a professional inspect.
DIY Fall Furnace Checklist
- Replace the air filter. Install a fresh filter before the first heating cycle. A clogged filter restricts airflow, causes the furnace to overheat, and can trip the high-limit switch.
- Check the flue pipe. Inspect the metal vent pipe from the furnace to where it exits the house for rust, disconnected sections, or blockages. Bird nests in the flue cap are a common fall problem.
- Clear the area around the furnace. Remove combustible materials stored near the unit. Maintain 3 feet of clearance on all sides.
- Test the thermostat. Switch to HEAT mode and raise the setpoint 5 degrees above room temperature. Confirm the furnace starts within 2-3 minutes.
- Check carbon monoxide detectors. Test batteries and CO detector function. CO detectors should be replaced every 5-7 years regardless of battery status.
- Listen to the first heat cycle. Unusual sounds (banging, rattling, squealing) during the first ignition of the season warrant a professional inspection.
What a Professional Fall Furnace Inspection Covers
- Inspect the heat exchanger for cracks -- the most critical safety check
- Clean the burners and test ignition
- Test the flame sensor -- dirty sensors cause the furnace to start and immediately shut off
- Measure flue gas temperature and combustion efficiency
- Test the high-limit switch and safety controls
- Check the blower motor and belt condition
- Measure carbon monoxide levels in the flue
- Inspect and clean the condensate drain on high-efficiency furnaces
Cost: $75-$150 for a professional furnace inspection and tune-up. If a maintenance contract is in place, the fall visit is typically included.
When to Call Immediately
Do not wait for a scheduled appointment if you observe: yellow or flickering flame (should be a steady blue), smell of gas (leave the house and call the gas company), carbon monoxide detector alarm, or visible cracks in the heat exchanger. These are safety issues that require immediate attention.
Frequently Asked Questions
- When should I get my furnace inspected?
- Schedule a furnace inspection every fall, ideally in September or October before cold weather arrives. This gives you time to address any issues found before you need the system and avoids peak-demand wait times in December and January.
- What does a fall furnace inspection include?
- A professional furnace inspection covers: heat exchanger inspection, burner cleaning, igniter and flame sensor testing, flue inspection, blower motor check, safety control testing, carbon monoxide measurement, and a combustion efficiency check. Combined with your own filter replacement and thermostat test, this keeps the system safe and ready for winter.
- What if my furnace does not start in fall?
- Check: thermostat set to HEAT mode with setpoint above room temperature, the furnace power switch (looks like a light switch near the furnace), the circuit breaker, and the air filter. Many fall no-start issues are simple fixes. If the system still does not start, schedule a diagnostic call before cold weather sets in.
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