Electrical Components

We check and tighten all electrical connections. Loose connections cause resistance, which generates heat and can lead to component failure or fire hazards. We also test capacitors (the components that help start and run the motors) and contactors (the electrical switches that control the compressor and fan motors). Capacitors and contactors are among the most common failure points in AC systems — catching a weak capacitor before it fails prevents a no-cool call on a 95-degree day.

Refrigerant Level

We check the refrigerant charge and verify the system is operating within the manufacturer's specified range. Low refrigerant reduces cooling capacity and efficiency, and causes the compressor to work harder. If refrigerant is low, we look for the source of the leak — adding refrigerant without fixing a leak is a temporary fix.

Coil Cleaning

Both the indoor evaporator coil and the outdoor condenser coil need to be clean to transfer heat efficiently. A dirty evaporator coil reduces airflow and cooling capacity. A dirty condenser coil makes it harder for the system to release heat outside, causing the compressor to run hotter and work harder.

We clean the condenser coil and inspect the evaporator coil. A heavily fouled evaporator coil may require a more thorough chemical cleaning.

Blower Motor and Belt

We check the blower motor's amperage draw (to verify it's not overworking), inspect the belt on belt-drive systems, and verify the blower wheel is clean. A dirty blower wheel reduces airflow significantly — sometimes by 30–40% — which affects both comfort and efficiency.

Drain Line

The condensate drain removes moisture that the system pulls from indoor air. A clogged drain line causes water to back up into the drain pan and eventually overflow — leading to water damage and mold. We flush the drain line and verify it's clear.

Gas Furnace: Safety Checks

For gas furnaces, we inspect the heat exchanger for cracks. A cracked heat exchanger can allow combustion gases — including carbon monoxide — to enter the living space. We also check the igniter, flame sensor, gas valve operation, flue pipe, and burner operation. These safety checks are the most important part of a furnace tune-up.

System Performance Verification

We measure supply and return air temperatures to verify the system is achieving proper temperature differential (typically 15–20°F for AC, 20–30°F for heating). We also check static pressure in the duct system, which can reveal duct leaks or restrictions that reduce efficiency.