Prepare Your AC Unit for the Summer Heat!

San Antonio does not ease into summer. One week it is pleasant, the next it is 96 degrees and the air conditioner is running ten hours a day and will not stop until October. Systems that were fine in April fail in June because they were asked to go from zero to full load overnight. A few hours of preparation in May keeps that from being your house.

Start with airflow

Replace the filter with a fresh pleated one and buy the next three. Vacuum the return grilles. Walk the house and make sure every supply vent is open and not blocked by furniture or rugs; closing vents in unused rooms does not save energy, it raises duct pressure and can freeze the coil. If any room is noticeably warmer than the rest, note it for the technician.

Clean the outdoor unit

Shut off power at the disconnect. Clear everything within two feet. Rinse the coil fins from inside out with a hose. Check that the pad is level and the unit is not sinking on one side. Look at the electrical whip and the refrigerant line insulation; sun-rotted insulation on the larger copper line is common in San Antonio and costs the system efficiency.

Flush the drain

Vinegar down the condensate line, then warm water. If it drains slowly, clear it with a wet-dry vacuum from the outdoor end. If your system has a secondary drain pan under the air handler, make sure it is dry and the float switch, if present, is working. Summer humidity in San Antonio produces gallons of condensate a day and the drain is the most common point of failure.

Test before the heat arrives

On a warm afternoon in May, set the thermostat five degrees low and run the system for 20 minutes. Check that supply air is cold, that the outdoor fan runs, and that the larger copper line is cool and sweating but not frosted. Listen for buzzing, grinding, or rattling. Any of these means a call now rather than in June.

Reduce the load on the system

Every degree the house does not gain is a degree the system does not have to remove. Close blinds on west and south windows in the afternoon, add solar screens or film to the worst windows, make sure the attic has adequate insulation and ventilation, and run ceiling fans counterclockwise in occupied rooms. Cook outside when you can. A 4-ton system in a well-shaded house behaves like a 5-ton system in an exposed one.

Program the thermostat now

Set 78 when home, 80 to 82 when away, with a pre-cool before the household returns. Resist large setbacks; the humidity recovery costs more than it saves. If you do not have a programmable or smart thermostat, this is the year to add one.

Schedule the tune-up

The professional visit measures what you cannot: refrigerant charge, capacitor health, motor amperage, static pressure, and coil condition. May calendars fill fast, so book early. Our A/C inspection takes about an hour and includes a written report. If the system is old enough that you are wondering about replacement, our system builder shows what a new installation would cost before anyone comes out. Call 210.549.4839.