Printable HVAC Maintenance Checklists

Before cooling season ramps up, check accessible ducts in your attic or crawlspace for gaps or disconnected joints. Sealing leaks can improve cooling efficiency by up to 20% and keep rooms cooler during St. Louis heat waves.

Winter frost heave can shift your AC pad. A unit that tilts more than 10 degrees strains the compressor and refrigerant lines. Re-level the pad or call a pro before the system runs under load.

Weatherstripping that cracked over winter lets cool air escape and humid St. Louis air in. Inspect seals and replace worn strips to ease your AC's workload and reduce cooling costs.

Set back temperatures 7-10°F for 8 hours a day (while asleep or away) to save up to 10% on heating and cooling annually. A smart thermostat pays for itself in the first St. Louis season.

Set a recurring reminder to check your filter. Most St. Louis homes need a new filter every 60-90 days; homes with pets or allergies every 30 days. Consistent replacement is the #1 way to extend HVAC system life.

Swap your air filter before the first St. Louis heat wave hits. A clean filter lowers energy bills, improves airflow, and prevents your AC from freezing up on 95°F+ days. Use a MERV 8-11 filter for most homes.

Trim bushes and remove leaves, grass clippings, and mulch within 2 feet of your outdoor AC unit. Restricted airflow forces the compressor to work harder and shortens system life. Do this after spring yard cleanup.

Book a spring cooling tune-up before the busy season. A NATE-certified technician checks refrigerant levels, cleans coils, tests capacitors, and verifies thermostat calibration — catching issues before a mid-summer breakdown.

Switch your thermostat from heat to cool and replace batteries. Verify it holds a set point of 76-78°F for optimal comfort and efficiency during St. Louis summers.

Swap out 1-inch filters every 30–90 days. A clogged filter forces your system to work harder, raising energy bills and shortening equipment life. Check monthly during peak season.

Remove leaves, grass clippings, and dirt from around your condenser. Maintain at least 2 feet of clearance on all sides for proper airflow.

Before cooling season, have a technician clean evaporator and condenser coils, check refrigerant charge, test capacitors and contactors, and verify airflow. Maximizes efficiency and prevents summer failures.

Pour a cup of diluted bleach (1:1 with water) down the condensate drain line in spring. This prevents algae buildup that causes drain pans to overflow and water damage.

Inspect the suction line (the larger, insulated copper line) running from your outdoor unit. If insulation is cracked or missing, replace it to prevent condensation and efficiency loss.

South-facing glass in St. Louis can add 15–25% to cooling loads. Cellular shades or solar screens on south and west windows reduce AC workload significantly during summer.

Turn on your AC for a full cycle in April/May before temperatures peak. Identifying problems early (no cool air, unusual noises, tripped breakers) avoids waiting 2–5 days for a technician in August.

Furnaces and AC units with a condensate pump should have it tested and cleaned each season. A blocked pump causes water overflow that can damage your system or cause flooding.