The 12-point furnace tune-up we do every fall

Here's exactly what our mechanics check before Idaho winter hits — and why every step matters.

A furnace that hasn't been touched in a year is a furnace waiting to fail on the coldest night. Our fall tune-up is 12 specific checks.

1. Heat exchanger inspection with a borescope — cracks here are a carbon monoxide risk, full stop.

2. Flame sensor cleaning. Ninety percent of 'won't stay lit' calls trace back to a dirty flame sensor.

3. Igniter continuity test. Hot surface igniters degrade slowly then fail suddenly.

4. Blower amp draw + capacitor test. A weak capacitor is a $12 part that prevents a $600 motor replacement.

5-12: Gas pressure, temperature rise, static pressure, thermostat calibration, condensate line, safety switches, exhaust draft, and filter fitment. Every step, every time.

The whole visit takes about 60 minutes and heads off nearly every winter emergency we used to run to.