North Shore Tips

Heat Pump Efficiency Tips NZ

Stop wasting money on your power bill. A modern heat pump is incredibly efficient, but only if you use it correctly. These are the exact tips Craig gives every customer after finishing an installation. Small changes in your settings can drop your monthly bill by 20% or more.

The 3-to-1 Rule

A heat pump does not create heat. It moves it. For every 1 unit of electricity you pay for, a well-run Toshiba or Mitsubishi unit gives you 3 to 5 units of heat back. But only if you use it right.

18-21°C The Goldilocks zone. Every degree above 21°C adds roughly 10% to your heating bill.
3-5x Heat output for every unit of electricity you pay for on a modern NZ unit
30% Harder the motor works when filters are dirty, especially in Takapuna and Milford salt air

Eight Tips That Actually Reduce Your Bill

A heat pump is only as efficient as the way you use it. These are the tips Craig gives every customer at handover on the North Shore. Small changes in how you run it make a real difference to your power bill. If your unit is struggling to keep up, the problem may be the unit size, not the settings.

01
Set it and forget it

Do not crank it to 28°C to "heat the room faster." It does not work like a car heater. A heat pump runs at full speed until it hits the target, then slows down.

Set 20°C and let the computer do the work. Every degree above 21°C adds roughly 10% to your bill.
02
Use the timer, not the switch

Turning a unit on from a dead cold start at 6am is the most expensive way to run it.

Use the timer to have the room at 19°C before you get out of bed. It uses less power to maintain heat than to create it from scratch.
03
Close the doors

Your high-wall unit was sized for your lounge, not your whole house. If you leave the hallway door open, the unit will struggle to heat that extra space and will never reach its economy mode.

Close doors to unused rooms and it reaches temperature faster with less effort.
04
The 8-week filter rule

On the North Shore, the air is salty. Pull your filters out every 8 weeks, rinse them in the sink and let them dry.

If you can see dust on the mesh, you are already paying too much for power. A dirty filter forces the motor to work 30% harder.
05
Trust Auto fan speed

Do not lock the fan on High. Put it on Auto. The unit will blast air until the room is warm, then whisper-quietly maintain it.

It saves the motor, saves power, and saves your ears.
06
Summer: Dry is the new Cool

Auckland summers are humid. Often you do not need the room colder, you just need the moisture gone.

Dry mode costs around 5 cents per hour. Cool mode costs 30 cents or more. Try Dry first.
07
Clear the garden

Check your outdoor unit after a storm. If leaves, spiderwebs or overgrown bushes are blocking the sides, it cannot breathe.

Keep at least 30cm of clear space on all sides. Debris collects fast in North Shore gardens.
08
The annual service

To keep your 10-year Toshiba warranty or 6-year Fujitsu warranty valid, you need a professional service once a year. Craig checks refrigerant levels and deep-cleans the coils.

A serviced unit runs 15% more efficiently than a neglected one, and lasts years longer.

Myths That Are Costing You Money

The three most common mistakes Craig sees on the North Shore, and the truth behind them.

MYTH
FACT

Crank it to 30°C to heat faster.

A heat pump runs at full output regardless of the target. 30°C does not heat faster. It just runs longer. Set 20°C.

Leave it on all day to save money.

Out for 2+ hours? Turn it off. Use the timer to preheat before you get home.

Cold air means it is broken.

It is in Defrost Mode, melting ice off the outdoor coils. Normal. Back to warm air in 5 minutes.

Only service it when something breaks.

By the time it breaks, it has been inefficient for months. $100-150/year pays for itself. Keeps warranties valid too.

What You Can Do Yourself

You do not need a technician for these. They take minutes and make a real difference.

Clean the indoor filters every 6-8 weeks

Pull them out, rinse under warm water, let dry fully before reinserting. Never run the unit with wet filters.

Check the outdoor unit monthly

Clear leaves, spiderwebs and debris from the sides and top. Keep at least 30cm clear on all sides.

Wipe the indoor unit housing

Dust and salt residue builds up on the casing. A damp cloth monthly keeps it clean and stops it working into the unit.

Check the condensate drain

A blocked drain pipe causes water to drip inside. Look for water marks on the wall below the indoor unit.

Book a professional service once a year

The internal coil, refrigerant level and electrical components need a technician. If Craig installed it, he services it. Running solar? See how to pair your heat pump with solar panels to cut running costs further.

Efficiency FAQ

Is it cheaper to leave the heat pump on all day or turn it on and off?

Turn it off when the house is empty for more than 2 hours. Leaving it running all day in an empty house costs more than using the timer. The exception is very cold days when it takes a long time to bring the house up to temperature. In that case leaving it on a low setting can be more efficient than a cold start.

What temperature should I set my heat pump to in winter?

18-21°C for most rooms. 18°C is comfortable for living areas when you are active. 20-21°C for bedrooms. Every degree above 21°C adds roughly 5-10% to your heating cost and does not make the room warm any faster.

How often should I clean my heat pump filters?

Every 6-8 weeks during heavy use, or at least every 3 months during lighter use. On the North Shore, salt air and coastal dust mean filters clog faster than inland areas. A blocked filter is the single most common cause of reduced efficiency we see on service calls.

Does a heat pump work less efficiently in very cold weather?

Yes, efficiency drops as outdoor temperatures fall. Most modern units have a rated operating range down to -15°C, but performance is best above 7°C. On the North Shore, temperatures rarely drop below 5°C overnight, so this is rarely an issue. Brands like Mitsubishi Electric with HyperCore technology maintain better output in the cold.

Why is my heat pump blowing cold air?

It is most likely in defrost mode. When ice builds up on the outdoor unit in cold, humid weather, the unit runs a short defrost cycle (usually 2-5 minutes) where it temporarily reverses the cycle. This is normal. If it is blowing cold air for more than 10 minutes, or the outdoor unit is not running at all, call Craig.

Want a Heat Pump That's Set Up Right From Day One?

Craig sets every unit to the right settings at handover and walks you through exactly how to use it efficiently. Free quote, no obligation.

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