Summer AC Preparation Checklist

Summer heat arrives faster than most homeowners expect. Taking the time to prepare your air conditioning system before the first heat wave ensures reliable comfort and avoids emergency repair scrambles.

Replace or Clean the Air Filter

Before starting the system for the first time this year, install a fresh filter. During summer, check the filter monthly and replace when dirty — typically every 60 to 90 days for 1-inch filters. Stock up with a multi-pack of Filtrete 1500 MPR Smart Air Filters at the start of the season so replacements are always on hand.

Schedule a Professional AC Tune-Up

An annual maintenance visit is the best investment in your cooling system. A technician will clean evaporator and condenser coils, check refrigerant levels, inspect electrical connections, test the capacitor and contactor, verify thermostat operation, measure supply and return temperatures, check the blower motor, clear the condensate drain line, and lubricate moving parts.

Professional tune-ups typically cost $100 to $250 but can reduce cooling costs by 5 to 15 percent.

Clean the Outdoor Condenser Unit

1. Turn off power at the disconnect switch and circuit breaker
2. Remove debris from the exterior
3. Use a garden hose with a gentle spray to rinse the fins from inside out
4. Straighten bent fins with a fin comb
5. Ensure at least two feet of clearance on all sides and five feet above

Never use a pressure washer on condenser fins — the thin aluminum bends easily.

Test the System

On a mild day, switch to cooling mode and set the thermostat below room temperature. Let the system run for at least 15 minutes. Watch for unusual vibrations or sounds, weak airflow, unusual odors, water leaking, or short cycling.

Thermostat Setup

Set to “cool” with fan on “auto.” The Ecobee SmartThermostat Premium can automatically switch between heating and cooling seasons and adjusts based on outdoor temperature and occupancy — eliminating the need to manually reprogram. Program a summer schedule:

• Home and active: 74 to 76 degrees
• Sleeping: 76 to 78 degrees
• Away at work: 78 to 82 degrees

Avoid setting the thermostat drastically low when you come home — the AC cools at the same rate regardless.

Ductwork Inspection

Check for Leaks

Inspect accessible ductwork for gaps, disconnections, and damage. Seal small leaks with foil tape or mastic sealant.

Ensure All Vents Are Open

Closing registers in unused rooms increases static pressure and can cause the evaporator coil to freeze. Keep all vents open and unobstructed.

Condensate Drain Maintenance

Your AC produces several gallons of condensate per day during peak cooling. If the drain line clogs, water backs up and overflows.

1. Locate the condensate drain line
2. Use a wet/dry vacuum to clear clogs
3. Pour vinegar or bleach-water through the access port
4. Repeat every three months throughout the season

Insulation and Window Efficiency

• Attic insulation: Ensure at least R-38
• Window coverings: Close blinds on south and west-facing windows during peak sun
• Weatherstripping: Replace worn seals around exterior doors and windows
• Solar screens or film: Apply to windows with the most exposure to reduce heat gain by 40 to 70 percent

Quick Reference Checklist

• Replace air filter
• Schedule professional tune-up
• Clean outdoor condenser unit
• Test the system on a mild day
• Program thermostat for summer
• Inspect ductwork for leaks
• Clear condensate drain line
• Check window coverings and insulation
• Test smoke and CO detectors
• Stock spare filters for the season

Complete these steps by mid-spring and your cooling system will be ready to handle whatever summer brings.