Completely switching off your heating or air conditioning before you leave may sound like a smart way to cut costs. But say letting the house drift too far from its usual temperature can force the HVAC system into a demanding recovery cycle later, which may raise your bill instead.

Here's what to know

Men's Journal first published this guidance on August 6, pointing to a mistake many homeowners make when they head out: shutting the HVAC system down entirely.

HomeServe USA HVAC Training Manager Randy Boutte said that approach can have the opposite effect people expect.

"When you set your thermostat too far from its normal setpoint, whether that's letting it get too hot in summer or too cold in winter, the system ends up running nonstop for an extended stretch just to bring the house back to your normal setpoint," he said.

Because the system then has to work through a long recovery period, energy use can increase, equipment can take on extra wear, and the next bill can be higher than expected. If you're already thinking about a replacement, Palmetto can help you explore efficient HVAC and heat pump options. Its Comfort Plan network can connect you with vetted installers and help you find heating and cooling solutions that could slash your energy bills.

Instead of flipping everything off, Boutte recommends a smaller adjustment: "A moderate setback of 5 to 7 degrees is a smarter approach: your system doesn't have to work as hard while you're gone, but it also won't be stuck playing catch-up for hours when you return."

More background

This issue can become more pronounced in older houses or in homes with weaker insulation, since indoor temperatures may climb faster after the system is turned off.

iHeat Operations Manager and Home Energy Expert Stephen Day said less-insulated properties can see the problem intensify: "When you leave an AC off while you're away, there's nothing to stop your home from heating up excessively, and this temperature rise would be further amplified if you live in an older property that's not insulated as well."

If the HVAC unit has to run for a long time to get the home back to a comfortable level, both the monthly bill and the strain on the system can increase, which may mean more repairs as the unit ages.

One of the strongest ways to reduce utility costs and buffer against rising energy prices is to upgrade your heating and cooling equipment. A higher-efficiency system can maintain comfort while using less energy, particularly during extreme heat or cold.

What can be done?

A practical starting point is to avoid dramatic thermostat changes, seal up drafts, and stay on top of maintenance so the system operates efficiently. Even modest tweaks can cut wasted energy without leaving the HVAC unit to recover from large indoor temperature swings.

If your current system is outdated or inefficient, Palmetto may be worth considering again. Through its Comfort Plan network, you can explore efficient upgrades, and if you're not ready to spend up front, the plan includes $0-down options that can lower your heating and cooling costs by up to 50%. Palmetto Comfort Plans also include 12 years of free maintenance, which can help you avoid additional service expenses.

Another way to lower utility expenses is to combine solar panels with electric appliances such as efficient HVACs. EnergySage makes it easy to find the best solar system and installer for your home and budget, and you can save up to $10,000 on installations.

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