Fact-Check: Is It Safe to Run Your Air Conditioner During a Thunderstorm?

It might sound like a silly myth, but running your AC during a thunderstorm can potentially damage your air conditioning and heating system. Here’s what you need to know to lower your risk of damaging your AC unit and needing to make costly repairs from your HVAC service provider.

How Can Thunderstorms Damage Your HVAC System?

Believe it or not, lightning strikes are your biggest risk to your HVAC’s safety during a thunderstorm. It’s rare for lightning to strike a home directly, but it’s still possible.

Your home’s electrical service drop (the point on your roof where power lines connect to your house) is a particularly vulnerable spot for lightning strikes. If lightning strikes it, that can cause a power surge through your home’s entire electrical system. And if your AC is running when this happens, the surge can cause significant damage to your AC – which can mean significant (and expensive) repairs.

What Kind of Damage Can a Power Surge Deal to My Air Conditioner?

A lightning strike can leave your AC damaged or even unusable. A power surge can melt your unit’s plug, damage the circuitry on the AC’s control panel, or corrupt the system controls on your heating and cooling system.

This can require extensive repairs or sometimes even require replacing the entire unit – an expensive fix.

How to Prevent Storm-Related AC Damage

If you live in an area that’s prone to frequent thunderstorms, you might want to contact a certified electrician to install a full-house surge protector. This can channel the voltage from a lightning strike into the ground instead of through your home. However, this isn’t 100% effective.

The most foolproof method is also the simplest: if you notice the weather starting to act up, turn off your AC. To play it extra-safe, turn your entire HVAC off at the thermostat.

Will Power Surges During a Storm Endanger My Family or Damage My Home?

Nope! If you’re running your AC during a thunderstorm and your house gets struck by lightning, the people inside your home and the home itself will still be safe. Power surges and damage to your air conditioning system aren’t any fun, but you can rest a little easier knowing they don’t pose any real damage to the people inside your home.

So while you certainly don’t want to leave your AC running if you’re at home and able to shut your system off, you don’t need to panic about it if you’re away from home or can’t get to your HVAC system to shut it off in time.

The Bright Side

When the weather’s hot, you rely on your AC more than ever. Luckily, during thunderstorms, humidity levels and the temperature outside generally drops significantly. So at least you won’t have to suffer in the heat; you won’t need your AC during the storm as much anyway.

The potential risk to your AC during a thunderstorm might sound exaggerated, but it’s a very real thing. To play it safe, keep your AC off during storms.

Scroll to Top
Need Plumbing? Click Here!