What to Do If Your AC Won’t Turn On After a Storm in St. Louis

After a storm, if your air conditioner won’t turn on, start by making sure your home power is on, check the outdoor unit’s safety switch, verify the thermostat has power and correct settings, inspect your breaker panel for tripped breakers, and reset any GFCI outlets. If all these steps fail, contact a licensed HVAC technician to avoid accidentally harming yourself or your system.

 

Initial Quick Checks

 

Before doing anything more complex, complete these simple steps:

• Confirm home power is on by checking lights and other appliances.
• Make sure the thermostat display is lit and set to “cool” with the temperature below room level.
• Look at the outdoor unit to see if the fan or compressor is trying to start.

 

Verify the Thermostat and Controls

 

Your thermostat is the control panel for your cooling system. If it has no display or buttons won’t respond, it may have lost power or its internal fuse blew.

• Replace batteries if it’s a battery-powered model. Use fresh, alkaline AA or AAA batteries.
• Check that the thermostat is set to “cool” and the target temperature is at least five degrees below the room temperature.
• If your thermostat has a circuit breaker or switch near it, ensure it’s in the ON position.

 

Check Your Main Electrical Panel

 

A storm often causes power surges that trip breakers inside your main panel. A breaker is an automatic switch that shuts off electrical flow when there’s too much current, protecting wiring and appliances.

• Open the panel door and look for any breaker in the “off” position or one that’s halfway between ON and OFF.
• Firmly move the tripped breaker fully to OFF, then to ON.
• If the breaker trips again immediately, leave it off and call an electrician—there may be a short circuit.

 

Inspect the Outdoor Unit’s Disconnect Switch

 

Next to your outdoor condenser unit there is a safety switch, sometimes in a small metal box. This disconnect cuts power to the unit for service or in emergencies.

• Open the metal box and flip the switch or pull the fuse handle out and then back in.
• If you feel resistance or see burn marks, leave it closed and get professional help.

 

Reset Safety Switches and Drain Pan Float

 

Modern AC systems have extra safety devices to prevent water damage if the condensate drain is clogged.

• Locate any ground fault circuit interrupter (GFCI) or arc fault circuit interrupter (AFCI) outlet in the garage, laundry room, or near the furnace and press the “reset” button.
• Inside your air handler, find the drip pan float switch. It stops the unit if water overflows. Gently lift the float—if you hear a click, reset power and try again.

 

Examine the Outdoor Unit’s Condition

 

High winds can deposit debris inside the condenser or damage its fan motor.

• Turn off power at the disconnect before inspecting.
• Remove leaves, sticks, or trash from around the base.
• Check that the fan blade spins freely by turning it gently—if it’s stiff or noisy, the motor may be seized.

 

When to Call a Professional

 

If the AC still won’t power on after these steps, there may be internal electrical faults, compressor issues, or damage from lightning. For safety and to protect your warranty, contact a licensed technician. Hoffman Brothers serves homeowners in St. Louis and also assists clients in Nashville with fast, expert repairs, ensuring your system is back up correctly.