Emergency HVAC Repair: What to Do When AC Breaks in Summer

Your AC stops working during a California heat wave. Indoor temperature hits 90F. Here's exactly what to do - in order - to stay safe and get the system back up as quickly as possible.

Step 1: Safety First in Extreme Heat

Before anything else, assess the situation:

If you have vulnerable household members (elderly, infants, anyone with heat-sensitive medical conditions): Don't wait for a repair. Get them to a cooled space immediately - a mall, library, neighbor's home, or hotel. Heat illness can develop faster than an HVAC repair can happen.

Know the signs of heat exhaustion: Heavy sweating, weakness, cold/pale/clammy skin, weak pulse, nausea. Move to a cool area and hydrate.

Know the signs of heat stroke (emergency): High body temperature, hot/red/dry skin, rapid strong pulse, unconsciousness. Call 911.

Step 2: Basic Checks Before Calling Anyone

Run through these quickly - they solve the problem about 30% of the time:

Check the thermostat: Correct mode (Cool), correct fan setting (Auto), target temp below current room temp. Replace batteries if blank.

Check the circuit breakers: There are usually two - one for the air handler and one for the outdoor unit. Both must be on. If one tripped, reset it. If it trips again, stop and call.

Check the air filter: A severely clogged filter can cause the coil to freeze, which triggers a safety shutoff. If the filter is dark and packed, replace it, then turn off the AC for 1-2 hours with the fan running to thaw the coil.

Check the outdoor unit: Is it running? Is there a disconnect box (a box on the wall near the outdoor unit) that might have been accidentally shut off? Check it.

Check for ice: Look at the copper lines going into the house from the outdoor unit. Ice on those lines means the system is frozen - needs thawing before it'll work.

If you've run through these and the system still isn't cooling, move to emergency service mode.

Step 3: Finding Emergency HVAC Service

Summer HVAC failures are everyone's worst-case scenario - and contractors know it. Emergency and after-hours service is available from most HVAC companies, but expect a premium.

Emergency pricing reality: - After-hours service fee (evenings, weekends): $50-$200 additional - Same-day availability: Often higher pricing across the board - Holiday rates: 1.5-2x standard rates

How to find emergency help fast:

When you call, immediately tell them: the make, model, and age of your system (printed on the outdoor unit or air handler), and what symptoms you're seeing. A well-prepared tech brings the right parts.

Step 4: Survive Until Help Arrives

While waiting for service:

Lower the indoor temperature: - Close blinds and curtains on sun-facing windows (reduces heat gain by 30-40%) - Move to the lowest floor (cool air sinks, hot air rises) - Use box fans to move air - airflow increases cooling even when it's hot

Create cooling: - Put ice in front of a fan (improvised evaporative cooling, works in dry California air) - Wet a towel and wear it around your neck - Take a cool shower

Reduce heat sources: - Turn off lights and electronics - Don't cook indoors - use microwave or eat cold food - Keep exterior doors closed except to get in/out

Step 5: What to Expect from the Tech

Diagnostic fee: Usually $75-$200 for emergency calls, sometimes applied to the repair.

Common summer failures: - Capacitor failure: Fast fix, $150-$350 - Refrigerant leak: $200-$1,500 depending on leak location - Contactor failure: $150-$300 - Compressor failure: $1,200-$2,500 (the expensive one)

If the repair is going to take days (parts on order): Ask about temporary options - a portable window AC ($150-$300 to buy or rent) buys you time.

After the Repair: Prevent Next Time

After any emergency repair, schedule a full tune-up before next summer. The component that failed usually isn't the only one showing wear. Catching the next weak component now costs $80-$150 in a tune-up; catching it next summer in an emergency costs $200-$400 in emergency fees on top of the repair.

Bottom Line

AC failure in a California summer heat wave: check filter/thermostat/breaker first. If those are fine, call emergency HVAC service immediately and tell them your system details. Stay cool by closing blinds, moving to lower floors, and using fans with ice while you wait.

Sources and editorial notes

Prices and permit requirements vary by location, property, equipment, and scope. Treat price ranges as planning estimates and confirm current requirements with the relevant authority and contractor.

• California Contractors State License Board - when a contractor license is required
• US Department of Energy - Energy Saver
• US Consumer Product Safety Commission - home safety

Related guides

• Air Conditioner Failure During a Heat Wave: Safe Cooling Plan
• What to Do When Your Heater Stops Working
• How to Prep Your Home for Summer Heat

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