The I.T. Bear’s Guide: High power bill? Why Turning Your Heat Pump Off Could Be Costing You More
The Winter Bill Shock: A Grizzly Tale
For many of us Kiwis, the arrival of winter brings a familiar dread—not just for the chilly mornings, but for the power bill that follows. It can be a real bear to open. As The I.T. Bear, I spend my days solving tech problems, but at night, I want a warm den without hibernating my bank account.
Now, I'll be honest, this is a bit of a read. But if you've got a heat pump and you're tired of those un-bear-ably high winter bills, I promise it's worth it. This article is based on a heap of New Zealand and global research, and you'll find all the links to the original studies and articles in the reference list at the end. We're going to bust some myths, look at real New Zealand research, and get your home warm and your wallet happy.
My secret to keeping bills down isn't just tech wizardry. A big part of it is making sure I'm not paying a cent more for power than I have to. That's why I created my own service, Buzz-Switch. It’s a simple, hassle-free way to check if you're on the best power deal and switch you if you're not. It’s the first, easiest step to saving money.
But the biggest culprit for most winter bills is heating, which makes up about a third of the average household's energy costs.(1) The old advice you’ve heard a million times, maybe even from power companies, is to "turn your heater off when you're not using it".(3)
Paws for thought on that one. That advice is a fossil from the age of clunky, inefficient heaters. With modern heat pumps, that logic is not just outdated; it could be the very reason your power bills are giving you a fright. Let’s dig into why.
The "Thermal Battery": Why Reheating Your Den from Cold Costs a Fortune
To get this, you need to stop thinking of your house as just a box of air. Think of it as a giant "thermal battery".(5) Everything solid in your home—the concrete floor, brick walls, even your dense wooden furniture—soaks up and stores heat. This is called thermal mass.(5)These things are like a giant, slow-charging heat sponge.
In New Zealand, many of our homes, especially those with concrete slab floors, have a huge thermal mass.(5) When your heating is on, these materials slowly absorb warmth. But when you turn the heat pump off and let the house get deeply cold overnight, the thermal battery completely discharges. Your furniture and floors become cold "heat sinks".(5)
This is the energy trap. When you blast the heat pump on a frosty morning, it’s not just warming the air. A massive chunk of that initial power goes into a brute-force fight to recharge that thermal battery—pouring expensive heat back into the cold concrete, bricks, and furniture.(5) This is why it can feel like it's running for an hour before you even start to feel toasty.
This whole process is a perfect storm of inefficiency. A heat pump works best when the difference between the outside air and the inside temperature is small.(8) By reheating from stone cold, you force it to do its hardest work at the worst possible time: early in the morning when it's coldest outside.8 It’s like flooring the accelerator from a dead stop every single morning—the most fuel-guzzling way to drive.
The Smart Heat Pump Strategy: Why "Set It and Forget It" Wins
So, what's a clever bear to do? For a well-insulated Kiwi home with a concrete slab or other thermal mass, the evidence points to a clear winner: a "set it and forget it" approach that maintains a constant minimum temperature.(10)
This works because of the inverter technology in modern heat pumps.9 An inverter is like cruise control for your car. It uses a burst of power to get to the right temperature, then it throttles right back, using just a tiny sip of energy to keep it there.(9)
My strategy, backed by experts, is to use the heat pump's timer or a smart controller to maintain a minimum temperature of around 16°C overnight.(3)
The next morning, instead of starting from a frigid 10°C, the heat pump only has to lift the temperature a few degrees to get to a comfortable 18-21°C.(1) This is a much shorter, less intense, and far cheaper heating cycle. The system works smarter, not harder, leading to real savings on your power bill.
A Warmer Den is a Healthier Den: The Undeniable Research
This isn't just about saving money; it's about keeping your cubs healthy. Since I adopted this heating strategy, I’ve noticed my family has had fewer winter colds. And the research backs this up.
The World Health Organization (WHO) states that 18°C is the safe minimum indoor temperature to protect your family's health.13 For homes with little ones or elderly family members, that number goes up to 20°C.1 Sadly, many Kiwi homes fall short. Temperatures below 16°C are linked to a higher risk of respiratory infections.(15)
Two major New Zealand studies prove the benefits:
The Warmer Kiwis Study: This massive study looked at the real-world impact of installing heat pumps. It found that homes with a new heat pump were, on average, 1.1°C warmer, and critically, these households reduced their winter electricity use by an average of 16%.(18) This proves you can be warmer and spend less.
University of Otago Research: Researchers found a direct link between warmer homes and better health. Installing an effective heater like a heat pump led to a 10% reduction in the onset of new chronic respiratory diseases like asthma. For kids under 15, that reduction was an amazing 15%.(20)
This shows that heating your home properly is a preventative health measure. It’s an investment that pays off in comfort, cash, and your family's well-being.
The I.T. Bear's Paw-sitive Power-Saving Checklist
To get the most out of the "maintain minimum temperature" strategy, you need to make sure your den isn't leaking heat. Here are some proven tips from Kiwi experts like Genless and Consumer NZ.
Tip 1: Defeat the Draughts
A draughty house is the enemy of a cheap power bill. Seal gaps around windows and doors with weather stripping tape or draught stoppers. It’s one of the most cost-effective things you can do.(22)
Tip 2: Master Your Curtains
Think of your curtains as another layer of insulation. Closing heavy, lined curtains at dusk traps a layer of air against the glass, dramatically reducing heat loss overnight.(3)
Tip 3: Clean Your Filters
A clogged filter makes your heat pump gasp for air, forcing it to work much harder and use more power. Clean the indoor filter once a month in winter. It’s a simple job that takes five minutes.(3)
Tip 4: Set the Right Daytime Temperature
Resist cranking the heat pump to tropical levels. A comfortable and healthy temperature is 18-20°C.(1) Setting it to 26°C can use up to 50% more electricity than setting it to 21°C.(3)
Tip 5: Use the Right Settings
Make sure your heat pump is in "Heat" mode (the sun icon), not "Auto". In "Auto" mode, it can accidentally start cooling on a sunny winter afternoon, which is just madness.(9) Set the fan to "Auto" and point the louvres down to circulate the warm air effectively.(3)
The I.T. Bear's Secret Weapon: Automating Your Comfort
Remembering to do all this manually is a hassle. This is where a bit of tech makes life so much easier. The built-in timer on your heat pump is a start, but a dedicated smart controller is the real game-changer.
This is where I recommend Sensibo. A Sensibo controller retrofits any remote-controlled heat pump and makes it truly smart. It's far more powerful than the clunky, built-in WiFi apps from manufacturers like Mitsubishi or Daikin, which often have terrible reviews and limited features.(24)
A Sensibo unit unlocks a suite of intelligent features that automate your savings:
Geofencing: It uses your phone's location to automatically turn the heat down when the last person leaves and warm the house up just before you get home. No more heating an empty house.(25)
Climate React: You can set rules to automatically turn the heat pump on or off if the room drops below a certain temperature or gets too humid. It’s perfect for maintaining that minimum 16°C overnight without you having to think about it.(25)
Learning Algorithms & AI: Sensibo learns your habits and the thermal properties of your home, then optimises your heating schedule for the perfect balance of comfort and efficiency.(30)
Advanced Scheduling: It offers a simple, powerful 7-day scheduler in the app, far easier to use than fiddling with a remote.(30)
Smart Home Integration: It works with Google Assistant, Amazon Alexa, and Apple HomeKit, so you can just say, "Hey Siri, turn up the heat".(25)
This is the ultimate expression of working smarter, not harder. It takes the guesswork out of the equation and ensures the perfect strategy is running 24/7.
The I.T. Bear is an expert in this stuff. If you want to make your heat pump truly smart, head to my contact page and ask for a quote to supply and install a Sensibo system.
Conclusion: Stop Paying for Cold Air
The path to a warmer, healthier, and more affordable home starts with ditching outdated advice. For most modern Kiwi homes, the evidence is clear:
Your home is a "thermal battery." Letting it go cold every night costs a fortune to recharge every morning.
Maintain a baseline temperature. Set your heat pump to hold a minimum of 16°C overnight. This keeps it in its most efficient "cruising" mode and reduces overall power use.
A warmer home is a healthier home. Keeping your home at a minimum of 18°C is a proven investment in your family's health, reducing the risk of respiratory illness.
Automation is the key. A smart controller like Sensibo removes the effort and ensures these strategies are implemented perfectly, saving you the most money.
By understanding these principles, you can turn your winter power bill from a source of anxiety into a testament to smart, efficient living.
The I.T. Bear can help with all of this. A great place to start is with my free Buzz-Switch service to make sure you're on the cheapest possible power plan. From there, we can look at smart automation to make your home work for you. Stay warm out there!
References cited:
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