When you arrange for annual maintenance for your gas or electric furnace, the technician will check all the unit’s critical components and tighten, lubricate, or test them as necessary. Specific tasks include:

• Vent system – Check for blockages
• Blower – Remove debris and check for proper operation and power draw
• Thermostat – Check that it’s properly calibrated
• Belts – Examining for damage, wear, or cracks
• Lubrication– All moving parts need lubrication to avoid wear
• Electrical connections – Inspecting, tightening, or replacing damaged wires
• Fuel source – In gas furnaces, the technician will check the burner and flame sensor
• Filter replacement– Every furnace filter must be replaced every three months. You’ll do most of these on your own, but a technician can replace your air filter at a tune-up.