AC Maintenance
A proper AC maintenance visit should check thermostat operation, filter condition, blower operation, evaporator coil condition where accessible, condenser coil cleanliness, condenser fan operation, capacitor, contactor, wiring, refrigerant performance, temperature split, condensate drainage, safety switches, system amperage, and overall cooling performance.
The outdoor condenser coil should be inspected for dirt, cottonwood, grass clippings, leaves, and blocked airflow. A dirty condenser raises pressure and stresses the compressor.
The indoor evaporator coil should be considered if there is weak airflow, freezing, odor, poor cooling, or filtration history. A hidden dirty coil can damage performance even if the outdoor unit is clean.
Condensate drainage should be checked because water damage can be expensive. The drain line, pan, float switch, and condensate pump should be inspected where applicable.
Furnace Maintenance
A proper furnace maintenance visit should check thermostat operation, filter, burners, ignition, flame sensor, ignitor, inducer motor, pressure switch tubing, venting, blower operation, temperature rise, limit operation, electrical connections, gas operation, flame quality, safety controls, and signs of corrosion or overheating.
For high-efficiency furnaces, condensate trap, drain tubing, vent pipes, intake pipes, and pressure switch operation are important.
The flame sensor may need cleaning if the signal is weak or the sensor is dirty. The burners should ignite smoothly. Delayed ignition, rollout, soot, or abnormal flame requires attention.
Heat Pump Maintenance
A heat pump operates in both heating and cooling seasons, so it often runs more hours than an AC-only outdoor unit. Maintenance should check both heating and cooling operation when practical.
Important checks include outdoor coil, indoor coil, blower, filter, refrigerant performance, capacitor, contactor, defrost operation, outdoor fan, thermostat configuration, auxiliary heat, emergency heat, drainage, sensors, and electrical components.
In winter, the outdoor unit should be checked for proper defrost and drainage. Heavy ice is not normal.
Ductless Mini Split Maintenance
Mini splits need filter cleaning, indoor coil inspection, blower wheel inspection, drain pan cleaning, condensate drain check, outdoor coil cleaning, refrigerant performance check, remote or thermostat operation check, and fan operation check.
Indoor mini split heads can collect dust and biological buildup. A dirty blower wheel can reduce airflow and create odor. A clogged drain can cause water to drip from the indoor head.
Filter Maintenance
Filters should be changed or cleaned based on system type, filter size, runtime, pets, dust, and filter condition. A one-inch filter may need frequent replacement. A media filter can last longer but still needs inspection.
The filter must fit correctly. A good filter is not useful if air bypasses around it.
Maintenance Documentation
A professional maintenance visit should document findings. The homeowner should know what was checked, what was cleaned, what readings were abnormal, what parts are weak, and what repairs may be needed.
Vague maintenance like “system checked, all good” is weak. Professional maintenance should create useful information.
Adapted from Haha's professional HVAC knowledge base for homeowner education and service planning.
Reviewed for accuracy: August 2026.
