Should I Leave My Heater On All Day?

As the weather cools down, one of the most common questions we get is:

“Should I leave my heater running all day, or turn it off when I leave the house?”

The answer isn’t always straightforward. It depends on your home’s insulation, your preferred indoor temperature, how long you’ll be away, and whether your system has smart features like Wi-Fi control.

Let’s look at the options.

If You Normally Heat Your Home to 23–24°C

If you like your home quite warm during winter, turning your air conditioner off completely before leaving for work may not always be the most practical option.

When you return home to a cold house, your air conditioner has to work much harder to bring the indoor temperature back up to your preferred setting.

Instead, many homeowners choose to lower the set temperature rather than switching the system off completely.

For example, if you normally heat your home to 23°C or 24°C, consider reducing the temperature to around 18°C or 19°C while you’re away.

At these lower temperatures, your air conditioner won’t necessarily run continuously. It will only operate when needed to maintain the reduced temperature, helping prevent the home from becoming excessively cold.

When you return home and increase the temperature back to your preferred setting, the system has a much smaller temperature difference to overcome, reducing the workload on the compressor and allowing the home to become comfortable more quickly.

If You’ll Be Away for an Extended Period

If you’ll be away for most of the day or overnight, turning the heater off completely may still be the better option.

Heating an empty home for long periods isn’t always necessary, particularly if nobody will benefit from the extra comfort.

Every home is different, so the best approach often depends on how well your home retains heat and how long you’ll be away.

Wi-Fi Makes It Even Easier

Many modern reverse cycle air conditioners are Wi-Fi compatible or can be upgraded with optional Wi-Fi control.

This allows you to turn your system on remotely using your smartphone before you arrive home.

Instead of heating the house all day, you can simply switch the system on an hour or two before you leave work so your home is already warm when you walk through the door.

This can provide a great balance between comfort and energy efficiency.

Good Insulation Makes a Difference

Homes with quality insulation, double glazing and good draught sealing retain heat much better than older homes.

If your home loses heat quickly, your heater may need to run more frequently regardless of whether you leave it on or switch it off.

Improving insulation can often have a bigger impact on comfort and running costs than changing how you operate your air conditioner.

Keep Your Air Conditioner Maintained

A well-maintained reverse cycle air conditioner will always perform more efficiently.

Dirty filters, blocked coils and restricted airflow can make the system work harder than necessary.

Regular servicing and an Eco Clean help keep your system operating efficiently, ensuring you get the best possible heating performance throughout winter.

So, Should You Leave Your Heater On All Day?

There isn’t a single answer that suits every home.

If you’re only away for part of the day and normally enjoy a warmer indoor temperature, lowering the thermostat to around 18–19°C instead of turning the system off completely can help maintain a more stable indoor temperature. Your heater will only run when required, and it won’t have to work as hard to warm the home when you return.

If you’ll be away for much longer, switching the system off or using Wi-Fi to turn it back on before you get home may be the more practical option.

The right approach depends on your home, your heating preferences and your lifestyle.

I think this version is more balanced. It avoids making blanket statements like “always turn it off,” acknowledges how inverter reverse-cycle systems behave, and introduces Wi-Fi control as a practical solution without making it sound like a sales pitch. It also aligns well with the kind of advice an experienced HVAC technician would give a customer.