Spring and summer are notorious for being hot and humid across much of the United States. That’s also the perfect recipe for severe thunderstorms. But you may want to think twice before turning your AC system on the next time the weather acts up – it could cause serious damage.
Rain alone generally will not harm an outdoor air conditioner. During a thunderstorm, however, turn the system off before lightning arrives when possible. Once thunder begins, avoid electrical equipment and wait at least 30 minutes after the last thunder before restarting the AC.
Can You Run the AC During Rain or a Thunderstorm?
Weather or System Condition | Run the AC? | Recommended Action |
|---|---|---|
Rain without thunder or flooding | Generally, yes | Outdoor AC units are designed to withstand normal rain. |
Thunder or lightning nearby | Best to leave it off | Turn the system off before the storm arrives when possible. Once thunder begins, avoid electrical equipment. |
Standing water around the outdoor unit | No | Stay away from the unit and have it inspected after conditions are safe. |
Storm has passed | Wait before restarting | Wait at least 30 minutes after the last thunder before restarting the system. |
Suspected lightning strike or power surge | No | Leave the system off and schedule an HVAC inspection. |
Air Conditioning Units and Lightning Strikes
Even though lightning striking a home is rare, if it does happen, it can really damage your air conditioning system. A nearby lightning strike can cause a power surge that damages an air conditioner, even when the system is not actively cooling. That’s way more than enough to damage your cooling system if it’s turned on.
What Can Happen If My AC Unit Takes a Lightning Strike?
For starters, lightning can melt the plug to your unit. In addition, it can damage the control panel and corrupt the entire system. The control panel is filled with sensitive electrical circuitry, so it’s best to turn it off when a storm hits.
A whole-home surge protection device can help protect HVAC equipment and other major appliances from many electrical surges. It must be installed by a qualified electrician. Additionally, no surge protector can guarantee protection from a direct lightning strike.
Signs Your AC May Have Storm Damage
Your air conditioner may have electrical damage if it will not turn on, repeatedly trips the circuit breaker, makes unusual noises, produces a burning smell, or runs without cooling your home. Leave the system off and schedule an HVAC inspection if these problems begin after a thunderstorm or power surge.
How Much Can Severe AC Damage Cost?
If storm damage is severe enough to require replacement, a central AC split-system replacement typically ranges from about $13,000 to $16,000, with cost driven by system size, efficiency, and installation complexity.
Can I Turn On The AC If It’s Raining?
Rain alone will not harm your air conditioner. In fact, turning the system on during warm, rainy days can make your home feel much more comfortable. The only time you would need to be concerned is if the rain was severe enough to leave standing water around the unit. In that case, it would be wise to power it down.
Keeping Cool During a Thunderstorm
A stuffy home during a storm can be uncomfortable, and turning off the system can be a hassle. However, a brief period of discomfort is generally much better than having to replace your air conditioning system.
Wait at least 30 minutes after the last thunder before restarting the system. During a thunderstorm, the air temperature drops considerably. If you can, consider opening the windows and turning on any ceiling fans to help pull cooled air in and around your home until the storm passes.
If you think your house or outdoor AC unit was struck by lightning, the HVAC pros at ARS/Rescue Rooter can properly examine your system and determine if any damage has occurred. Call us right away, or book an appointment online to have us inspect your system and check for any air conditioning repair needs.
Frequently Asked Questions
Yes. Normal rain generally will not harm an outdoor air-conditioning unit. Shut the system down if floodwater or standing water reaches the equipment.
Turning the system off does not completely disconnect it from the electrical system. A lightning-related power surge may still reach connected HVAC equipment. A professionally installed whole-home surge protector can reduce damage from many surges but cannot guarantee protection from a direct strike.
Wait at least 30 minutes after the last sound of thunder before resuming normal activities or restarting the system.
Possible warning signs include a system that will not start, repeated breaker trips, unusual noises, a burning odor, or an AC that runs without cooling. Leave the system off and schedule an inspection if you suspect electrical damage.
