How to get my AC ready for heat waves

Why preparing your AC for heat waves matters

Heat waves push central AC, ductless mini-split, and rooftop unit systems to their limits. High ambient temperatures reduce heat transfer, raise static pressure in ductwork, and expose weak electrical components. Smart preparation improves comfort, protects equipment, and helps keep energy bills in check. Just as important, some insurers have insurance requirements HVAC owners must follow after damage; unsafe DIY work can void warranties or complicate claims. Safety, documentation, and code compliance matter.

Safety and insurance note

Anything involving refrigerant, high voltage, gas lines, or structural changes should be handled by a licensed HVAC professional. Many policies and local codes require qualified specialists for refrigerant charge, coil cleaning with chemicals, new circuits, rooftop service, or duct alterations. Keep invoices and photos as proof of maintenance.

Pre–heat-wave AC readiness checklist (DIY-friendly)

1. Replace or upgrade your air filter. Use a clean MERV 8–13 filter. During wildfire smoke events, a MERV 13 filter can improve indoor air quality. Check monthly in summer; replace sooner if it looks dirty. Do not oversize the filter or starve airflow, which can cause coil icing and short cycling.

2. Calibrate and schedule the thermostat. Verify the reading with a separate thermometer. Program pre-cooling: set to 74–76°F two hours before peak grid hours, then 78–80°F while home. When away, 82–85°F. Pre-cooling reduces compressor strain. Smart thermostats can automate demand response and thermostat pre-cooling.

3. Clear the outdoor condenser. Maintain 24 inches of clearance. Gently rinse coils from the inside out with low-pressure water; do not bend fins. Ensure the unit is level for proper oil return. Provide shade without blocking airflow.

4. Check supply and return vents. Open at least 80–100% of registers in used rooms. Vacuum return grilles. Closed vents can raise static pressure and reduce SEER2 performance.

5. Condensate drain health. Pour warm water with a little vinegar into the drain line to discourage algae. Confirm the condensate pump (if any) cycles. A clogged drain can trigger water damage and insurance claims.

6. Quick duct check. From accessible spaces, look for crushed flex runs, disconnected boots, or gaps. Use mastic or approved tape on minor leaks. Full duct sealing or redesign should be pro-handled due to testing and code requirements.

7. Electrical basics. Verify the dedicated breaker is labeled and snug in the panel. If you have a surge protector, confirm indicator lights are green. Do not open the condenser or handle live conductors; have a technician test capacitors, contactors, and compressor amps.

8. Reduce solar gain. Close blinds on sun-facing windows, add reflective shades, and seal obvious gaps. Attic insulation and weatherstripping help your AC maintain set points during heat waves.

9. Emergency plan. Know where the disconnect switch is, identify safe indoor temperatures for vulnerable occupants, and stage portable fans as backups.

When to call a qualified HVAC professional

• Warm air from vents, weak airflow, or rooms that never reach set point
• Short cycling, ice on lines or coil, or repeated breaker trips
• Unusual odors (electrical, musty), rattles, or buzzing
• High indoor humidity, water near the air handler, or a tripping float switch
• Visible oil stains on refrigerant lines or suspected leaks
• Any work involving refrigerant charge, electrical components, or rooftop service (EPA and code compliance apply)

Refrigerant handling requires EPA 608 credentials. Many warranties and insurance requirements HVAC policy terms expect licensed documentation for refrigerant charge, coil cleaning, or equipment changes.

What a professional tune-up addresses before a heat wave

• Refrigerant charge and leaks. Proper superheat/subcool ensures efficiency and protects compressors. Pros pressure-test and evacuate systems, then verify SEER2 performance.
• Coil and blower cleaning. Deep cleaning of the evaporator coil, condenser coil, and blower wheel restores airflow and heat transfer. This often includes safe coil cleaning chemistry and rinsing techniques.
• Electrical testing. Inspect disconnects, measure compressor and fan motor amps, test capacitors, and replace pitted contactors. Torque checks on lugs reduce overheating risk during heat waves.
• Airflow and duct design. Measure total external static pressure, balance registers, add returns, or perform duct sealing where needed. In complex homes or commercial spaces, a load calculation and zoning review may be recommended.
• Thermostat and controls. Fine-tune staging, fan profiles, and smart pre-cooling to reduce peaks and improve indoor air quality.

Southern California heat-wave specifics

• Wildfire smoke. Run the system on recirculate. Use a MERV 13 filter where the blower and duct design can support it. Consider portable HEPA units for bedrooms. Keep windows shut during smoke events.
• Coastal vs. inland. Coastal salt can corrode coils; inland dust clogs filters faster. Rooftop unit inspections should include cabinet sealing and UV exposure checks.
• Demand response. Pre-cool 2–3°F before peak hours (commonly 3–9 pm). Thermal mass helps ride through curtailments without sacrificing comfort.

Efficiency tips that pay off

• Seal the building envelope: caulk big gaps first; then consider attic insulation.
• Use ceiling fans to feel 3–4°F cooler at the same set point.
• Shade west-facing glass and the condenser (with full airflow clearance).
• Keep interior doors open to improve return air paths.
• Consider zoning or a ductless mini-split for hard-to-cool spaces and additions.

Our engineering heritage and mission

#1 AC Guys is a family HVAC company in Southern California, serving Los Angeles County and nearby areas including Orange County, Ventura County, and Western Riverside County. Our fourth-generation family of engineers brings 80+ years of engineering experience to residential and commercial projects, especially large and complex installations. Our mission is simple: healthy air at home for a healthy life.

Our engineers completed manufacturer-led training at the factory facilities of Fujitsu (Japan), Mitsubishi Elektrik (Thailand), Midea (China), Gree (China), and Hier (China). We specialize in central AC, split system, mini-split, and rooftop unit solutions where careful airflow design, static pressure control, and indoor air quality strategies matter most.

Service area examples

We regularly work across Los Angeles County (Los Angeles, Long Beach, Pasadena, Santa Monica, Glendale, Burbank), Orange County (Anaheim, Irvine, Santa Ana, Huntington Beach, Costa Mesa, Fullerton, Orange, Newport Beach), Ventura County (Oxnard, Ventura, Thousand Oaks, Simi Valley, Camarillo), and Western Riverside County (Riverside, Corona, Moreno Valley, Temecula).

Heat-wave readiness recap

Use the AC maintenance checklist above to handle simple filter, airflow, condensate, and thermostat tasks, then schedule professional testing for refrigerant charge, coil cleaning, and electrical inspection. With smart pre-cooling, clean ducts and coils, proper duct sealing, and good building envelope practices, your system will be safer, more reliable, and ready for the next heat wave.