What to Do If Your HVAC Stops Working During a Storm in St. Louis

If your HVAC stops working during a storm, immediately turn off its power at the thermostat and breaker box to prevent damage. Then check your home’s circuit breaker, clear any debris around the outdoor unit, and wait for the storm to pass. Once it’s safe, switch the system back on and test it. If it still fails to run, call a qualified technician.

 

Immediate Safety and Power Shutdown

 

• Go to your thermostat and switch it to “off.” This prevents short-cycling when power returns.
• Find your home’s electrical panel and flip the breaker labeled “HVAC” or “AC” to the off position.
• If you have a separate disconnect box near the outdoor unit, open it and switch it off too.

 

Locate and Inspect the Circuit Breaker

 

• Check if the breaker has tripped (the switch is midway or in the “off” spot). Tripping often happens during power surges or outages.
• If it has tripped, wait 30 seconds, then firmly reset it to “on.”
• If it trips again immediately, leave it off and do not attempt further resets—this indicates an electrical fault.

 

Examine the Outdoor Unit Carefully

 

• Only when rain or wind has subsided, walk outside and look at the condenser (the metal box with a fan on top).
• Remove leaves, sticks, or other debris that may block airflow or damage fins.
• Check for visible damage like bent fins, loose panels, or damp electrical components.

 

Wait Until the Storm Has Fully Passed

 

• High winds and lightning pose serious hazards. Only work on your system once all thunder, heavy rain, and lightning have ended.
• Restoring power during a storm can cause voltage spikes that harm electronics and motors.

 

Safely Restore Power and Test the System

 

• Go back to the indoor breaker and switch the HVAC breaker to “on.”
• Flip on the disconnect switch near the outdoor unit if you turned it off earlier.
• Set your thermostat to cooling or heating mode and raise or lower the temperature setting to demand operation.
• Listen for the outdoor fan and compressor to kick on and feel air flow from your vents within a few minutes.

 

When to Call a Professional HVAC Technician

 

• If the breaker trips again or you notice burning smells, sparks, or smoke—shut everything off and stay clear.
• If the outdoor unit makes loud grinding noises, vibrates excessively, or fails to start after power is restored.
• For any refrigerant leaks (oily residue or hissing sounds), which require EPA-certified handling.
• Whether you’re in St. Louis or Nashville, a trained technician can safely diagnose electrical or mechanical damage, replace parts, and restore system performance.

 

Staying calm, following these steps in order, and knowing when to call a professional will protect your HVAC system and ensure safe, reliable operation once the storm has passed.