5 things you should stop right now if you want your AC to survive a heatwave

The weather is officially going crazy. From extreme snow to extreme heat, everything is a little off kilter in the U.S. right now. And while we adjust to the swings in climate, the East Coast is about to experience a record-smashing heatwave, according to the National Weather Service.

When the heat is on, you’re going to want to get the most out of your air conditioner to help you keep cool. However, there are five common mistakes that could leave you hot under the collar while you battle the heat.

1. Setting the AC temperature too low

Woman adjusting smart thermostat — (Image credit: Shutterstock)

Cranking your AC control down to the lowest temperature, thinking it will cool your home faster, isn’t the answer. Your AC unit cools at a constant rate, regardless of the temperature it is set to. By drastically reducing the temperature, you’re creating added pressure on the system, which can increase your energy bills without cooling your home any quicker. Changing your AC setting from 70°F to 65°F won’t speed anything up.

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If anything, your AC will keep working even once it’s reached a comfortable temperature — say 72°F — and will keep going until the room reaches 65°F, at which point you’ll probably be too cool, and it will cost you more money.

2. Neglecting your coils and filters

Dirty filters and coils are among the most common causes of AC issues, especially when it’s hot. When coils and filters are not cleaned and maintained, airflow becomes restricted, and the system has to work harder to perform. But because you can’t see the coils and filters without opening your system, it’s easy to forget they need cleaning. This oversight not only makes your AC go into overdrive, but it also costs more to run.

The best advice is to check your AC system monthly and clean out the coils and filters, replacing the filters when needed. However, during a heatwave, when your system is working nonstop, the filters will clog faster, and should be checked every two weeks, especially if the temperature rises above 95°F outside.

3. Turning your AC off when you're out

If you’re spending most of the day out at work, you may think it’s more energy-efficient to turn off your AC when you're out and switch it on when you’re back home, but this is not the case.

In an experiment carried out by Wirecutter, it was discovered that it cost more to run an AC system when it was turned off than when it was left on all day. But, for optimum efficiency, instead of leaving your thermostat at a comfortable 72°F, it’s best to turn it up to around 78°F. Then, once you return home, you can reduce it once more.

AC units use much less energy to maintain a steady temperature than to manage larger fluctuations in cooling demand.

4. Closing air vents

HVAC vent — (Image credit: Shutterstock)

It might seem like common sense to close air vents in unused rooms to contain the cool air, but doing so can hinder your AC system's performance and even damage the ductwork. Instead of being more efficient, it unbalances the system, increases pressure in the ductwork and can lead to leaks.

Instead of closing vents, it’s best to use smart thermostats in these rooms to manage the temperature correctly. Leaving the doors open, rather than closed, will also help.

5. Missing warning signs

If your AC system is aging, extreme heat can push its electrical parts past their limit. Comfort By Design says that capacitors, contactors, and motors are more likely to fail when an AC system is running for long periods without a break.

Other signs not to ignore that indicate your system is struggling include it struggling to start, a loud humming noise when it is running, the outdoor fan not spinning, or the breakers tripping. In any of these circumstances, don’t disregard them. It’s a sign your system needs a service or repair, giving you the opportunity to catch any problem before it escalates.

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Camilla is the Homes Staff Writer and covers everything to do with homes and gardens. She has a wealth of editorial experience, mounting over 30 years, and covers news and features, tests products for reviews and compiles buying guides.

Her work has appeared in business and consumer titles, including Ideal Home, Real Homes, House Beautiful, Homebuilding & Renovation, and Kitchen & Bathroom Business. She’s even appeared on the cover of Your Home, writing about her own house renovation.

Although she’s obsessed with decorating her home, she also enjoys baking and trying out the latest kitchen appliances. But when she’s not inside, you’ll find her pottering about in her yard, tending to her vegetable patch or taking in her prized hydrangeas.

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