Big guzzlers: 3 things you're doing that are racking up your energy bill

By Bron Maxabella

Whether it’s warming your home in winter, enjoying extra-long showers, or keeping the fridge full for family visits, certain everyday habits can quietly rack up your power bill. 

The top 3 energy-guzzlers in the average New Zealand home are:

• Ducted air-conditioning/heating
• Hot water systems
• High-energy appliances: ovens, dryers, fridges, dishwashers

In fact, together these juice drainers are responsible for the majority of your energy costs.

Which is actually good news as it means that by focusing on reducing your consumption in just 3 areas, you can significantly cut your bills – all while keeping your home just as comfortable. 

Let’s delve a little deeper into each area to find the most effective ways to save.

1. Using your heating or cooling inefficiently

Blasting the air con or heater? You could be burning through your budget too.

New Zealand’s varied climate means heating and cooling systems play a major role in home energy use - especially in colder regions. Heating alone can account for around a third of a household’s energy bill. Inefficient use, like setting a heat pump too high, can significantly drive up costs. For example, running a heat pump at 26°C uses about 50% more energy than setting it to 21°C.

A well-insulated home is key to reducing energy loss and improving comfort. Poor insulation allows warm or cool air to escape, making systems work harder and increasing expenses.

Heating or cooling only the room you’re using is another way to make a significant difference to your energy use in this area. Image: iStock/fizkes

To optimise energy consumption, it's recommended to use timers to operate heating or cooling systems only when needed, and to set thermostats to a comfortable 21°C.

The real key is to keep the heat or cold out in the first place:

• In summer, shut your blinds and windows before the heat of the day creeps in. In winter, open those blinds to let the sun naturally warm your space.
• Pop a draft stopper at the bottom of external doors to keep the outside temperature from sneaking in.
• If you’ve got the space, plant some leafy trees near your windows – deciduous ones are great because they give shade in summer but still let the sunshine in during winter.
• Add retractable shades (especially on the north and west sides of your home) to help block the harshest sun in summer or let it in during winter.
• And on scorching days, skip the oven – you’ll just further heat up the house. Use a more energy-efficient air-fryer instead. 

Boosting your ceiling and wall insulation and window glazing and sealing can also make a world of difference to keep your home comfy year-round. It will reduce your energy bills in the long run, but does require money upfront to install. 

2. Check your hot water system

No surprises here, your hot water system is one of the biggest energy guzzlers in your home – second only to heating and cooling. For most Kiwi households, that equates to 34% of your energy bill on average. So keeping your hot water system in good shape can make a noticeable difference to your energy bills. 

Regular servicing by a licensed tradesperson ensures your system is running efficiently, safely and not working harder than it needs to. Over time, sediment can build up, valves can wear out, and small issues can quietly turn into costly problems. A quick check-up can extend the life of your system, reduce your energy use and give you peace of mind that you’re not paying more than you should for every shower, wash and laundry load.

Here are more ways you can make your hot water system more efficient:

Turn down the temp

In New Zealand, it's essential to balance hot water temperatures to ensure safety and prevent bacterial growth. Level (the authority on sustainable building) requires that stored hot water must be heated to at least 60°C daily to prevent the growth of Legionella bacteria. Any higher than that means you’re using energy unnecessarily.

It’s expensive to install a dedicated solar hot water system and it may take years to see the bottom-line benefits. Fortunately, you can get a similar result by running an electric hot water system from your general solar supply.

There are a couple of great ways to make the most of your solar power when it comes to heating your water – even if you don’t have battery storage. 

1. Use a timer: One option is to pop your hot water cylinder on a timer so it heats up during the day, making the most of your solar power while the sun’s out. Do check that this strategy is worth it for your setup, especially on cloudy days when you could end up paying peak rates to heat your water. 
2. Install a diverter: Another smart solution is a hot water PV diverter, which automatically sends any extra solar energy straight to your electric hot water system. It’s a clever way to cut your reliance on grid power – and under the right conditions, it can save you money and store energy more affordably than a battery.

Switch to a low-flow shower head

Showers are where your hot water gets the biggest workout – and your energy bill feels it. A good low-flow shower head uses far less water but still feels fabulous. When shopping, look for a 3-star rated showerhead with a high water rating and a low flow rate (yep, the lower the flow, the bigger the savings).

Keep showers short and sweet

We all love a long, steamy shower – but if you're in there long enough to sing, say, Don McLean’s American Pie from start to finish, it's time to cut back. Try aiming for a 4-minute or shorter shower. Keeping a waterproof timer in the shower (like this cute one) can help you keep track. 

Radiohead ‘I Will’, yes. Pink Floyd’s ‘Dogs’, no. Image: iStock/Volodymyr Zakharov

Wash clothes in cold water

Unless your clothes are extra grubby, cold water generally gets the job done – and it's much kinder on your fabrics and your energy bill. Bonus: your favourite top won’t fade as fast.

Fix that pesky drip

A dripping hot water tap isn’t just annoying, it’s pouring dollars down the drain. A quick fix can save hundreds of litres and the energy it took to heat them. That’s no exaggeration, just watch how fast your dripping tap fills a bucket…

Wrap your hot water pipes in a cosy jumper

Okay, not an actual jumper – but insulating your exposed hot water pipes (especially the ones outside) helps stop heat escaping. Look for closed-cell rubber insulation at your local hardware store. It’s a quick job that makes a difference.

3. Cool your fridge and freezer use

Your fridge and freezer are on 24/7, making them the third biggest energy user in your home (around 10% of your energy bill). But a few small tweaks can make a big difference to your energy bill.

• Give it space: refrigerators and freezers need airflow to operate efficiently. Leave a gap of at least 5cm around all sides of the fridge and don’t place your fridge near the oven or in direct sunlight.
• Check the temperature settings: Set your fridge thermostat between 3°C and 5°C, and your freezer between -15°C and -18°C. Lower temperatures require more energy and may not provide additional benefits.
• Give the door seals a once-over: if they’re loose or cracked, cold air escapes and your appliance works harder (and uses more power) to stay cool. You can test the seal by closing the door on a piece of paper, if it slips out easily, it might be time for a replacement.
• Keep it shut: constantly opening the fridge or freezer door allows warm air inside, which means the thermostat needs to crank up to maintain the set temperature. This drains energy and costs you money. Instead, think ahead about what you need and try to get everything in one go.
• Say no to seconds: sorry, but your ‘beer fridge’ is costing you plenty, especially if it’s an older-model fridge cranking away in the heat/cold of your uninsulated garage. Fridges operate best when they’re at least 3-quarters full, so maybe you can find room in your ‘everyday fridge’ after all?

Finally, if your fridge is more than 10–15 years old, it might be worth upgrading to a newer, energy-efficient model. The upfront cost often pays off in long-term savings.

Have we missed a top tip? Let us know in the comments.

^{Feature image: iStock/shurkin_son}

More ways to save:

• 9 creative ways to save on your grocery bills
• 7 ways to make debt disappear
• 16 things you can do right now to save big on your energy bill

This article reflects the views and experience of the author and not necessarily the views of Citro. It contains general information only and is not intended to influence readers’ decisions about any financial products or investments.  Readers’ personal circumstances have not been taken into account and they should always seek their own professional financial and taxation advice that takes into account their personal circumstances before making any financial decisions.