Monitor the things you can see safely
Filter condition, thermostat operation, blocked registers, outdoor-unit clearance, water, ice, noise and unusual odors can provide early warning that something has changed.
Maintenance Guides
Keep the complete HVAC system in view
Maintenance is more than changing a filter. Airflow, drainage, outdoor equipment, controls and seasonal operating conditions all deserve attention.
Maintenance
HVAC Maintenance Checklist
A practical year-round checklist for homeowners.
Read guide →MaintenanceHow Often Should HVAC Be Serviced?
Understand useful service timing for heating and cooling equipment.
Read guide →MaintenanceAir Filter Guide
How filters affect equipment cleanliness, airflow and indoor particles.
Read guide →MaintenanceHow Often Should You Change an HVAC Filter?
Why filter-change intervals depend on the home and system.
Read guide →MaintenanceSpring AC Maintenance
What to check before cooling season begins.
Read guide →MaintenanceFall Furnace Maintenance
What to check before the heating season.
Read guide →MaintenanceHeat Pump Maintenance
Maintenance considerations for equipment that runs in both seasons.
Read guide →MaintenanceOutdoor Condenser Maintenance
Clearance, coil condition and what not to do around the outdoor unit.
Read guide →MaintenanceCondensate Drain Maintenance
Why drainage matters and what water around indoor equipment can mean.
Read guide →MaintenanceDuctwork Maintenance
What to watch for with ducts, registers, returns and accessible flex duct.
Read guide →MaintenanceThermostat Maintenance & Batteries
Simple thermostat checks that can prevent avoidable service calls.
Read guide →MaintenanceBefore Leaving for Vacation
A practical HVAC checklist before an extended trip.
Read guide →Measurements matter
A proper service visit can involve electrical readings, operating temperatures, airflow, refrigeration measurements, combustion checks and inspection of components that should not be accessed casually by a homeowner.
Something Already Wrong?
Maintenance and troubleshooting are not the same thing
If the system is already freezing, leaking, short cycling, failing to heat or cool, or making a new severe noise, use the Troubleshooting Center or request service rather than treating the condition as routine maintenance.
Related Resources
Continue with the right next topic
HVAC Maintenance Checklist
Start with the complete homeowner maintenance checklist.
HVAC System Age Finder
Estimate equipment age when planning service or replacement.
Troubleshooting Center
Move to symptom-based guidance when maintenance reveals a problem.