Posted by Brendan White | Published: Tuesday 02 August 2022 | Last updated: Monday 08 August 2022

Anywhere from $2000-$5500, depending on a whole range of factors. If you just needed the headline figure, you could stop reading here. But, if you’re interested in finding out what goes into determining the price, we’ve put together this article to help you get across it.

Here, we draw together knowledge from our 15 years in the business to go through everything that makes a heat pump more or less expensive.


A big factor in the cost of a heat pump is how efficient it is. This is expressed by its Coefficient of Performance, or CoP, a number that shows how much heat can be generated from 1kW of power. For example, a CoP of 4 will generate 4kW of heating power from 1kW of electricity. (For comparison, an electric instant heater will use 1kW of electricity for 1kW of heating power.)

The higher the efficiency of the system, the more it’ll set you back. The flipside, of course, is that you’ll be saving more money over time by using less electricity. Once your system has paid for itself in savings, you’ll see more value from higher efficiencies.

Since heat pumps pull heat from the air, hotter temperatures increase CoP and lower ones decrease it. That’s why it’s best to look at average CoP.

An average CoP of 5 is indicative of a high quality system, and one that you’d expect to pay more for. Cheaper systems will come with CoPs of 3-4, though keep in mind you’ll save less over time.

Operating Temperature

Any heat pump should run fine on a 24°C day, but the differences start to become stark as the temperature drops. The colder your heat pump can operate, the more expensive it’ll be.

A great heat pump (and, naturally, more expensive one) can operate up to around -10°C. Other units may work up to -7°, -5°, or may even stop as early as 5° for budget models.

To compensate for relatively high minimum temperatures, some systems will use an electric booster. When it gets too cold, the booster takes over from the heat pump. This ensures you’ll have hot water on cold mornings, but it does mean you have to use significantly more power for it. Any efficiency from the pump is lost when relying on the booster, since you’re essentially just running an electric storage system.

When you see a system advertise low operating temperatures, make sure that’s how low the heat pump will operate, and not just the system as a whole – some will advertise working as low as -20°C, when what they mean is the booster functions until then, and the heat pump actually stops much earlier.

Also, keep an eye out for all-in-one systems that advertise “dual heating.” This means the heat pump will get the water heated most of the way, then finish it off with the electric element.

Obviously, a lower operating temperature is better because it keeps you well supplied with hot water overnight. Though, those in a warmer climate may not need this and might be able to safely choose a cheaper system.

Tank size and type

How large your system’s tank is, and what it’s made of, will affect the price.

For starters, a glass-lined tank tends to be cheaper than a stainless steel one. This is basically a mild steel tank with a vitreous enamel lining, and it’s better for properties that use bore water, or water with a high mineral count. The trade-off is that these tanks won’t last as long as stainless steel. If your property has low-mineral water, then a stainless steel tank will last longer – and with a longer warranty, most likely.

As you might expect, larger tanks are more expensive. A family of four will typically need a 270-315L tank, but that might be higher if you use a lot of hot water. It’s a good idea to try find out how much hot water you’re using, and then talk with a professional you trust to find out what sized tank you need.

While a larger tank requires more energy to heat, it’s not always the case that a smaller tank will cost less over time. A highly efficient system with a 315L tank may end up being cheaper to run than a less efficient system with a 170L tank. Remember, the efficiency is in the compressor itself, and the tank is a lesser consideration.

gstore-heat pumps-landing page banner-grey-6

Refill/recovery rate

This is closely related to both efficiency and the tank size. A system’s refill/recovery rate is how quickly it can heat a given amount of water. Let’s say you have a large household that uses more than 450L of water a day. While it might seem like you need a tank larger than that, that’s not always the case.

Imagine that use is spread out to three times a day, and the most you use concurrently is 150L. As long as your system is capable of reliably reheating enough water, you might not need to have a massive tank. Working out how much water you use – and when you use it – can help you determine what’s best.


Durability is often missing from conversations about how much money you can save when you upgrade your hot water system. If you have to pay for a full replacement system after six years, you obviously pay more than if your system lasts for 15 years.

In our experience, paying more upfront gets you a longer lasting system. When you buy a $5,000 heat pump, that tends to be the end of it. When you buy a $2,500 heat pump, you’ll often find yourself spending more to replace it down the line.

Depending on efficiency, it might take longer for a premium system to pay itself off – though you should expect to save more overall by the end of the system’s life.


The last factor in price has little to do with the heat pump itself. For Victorians, there are three types of rebate, each with different conditions.

STCs are issued by the federal government and give you a point-of-sale discount based on how efficient your system is. (We have an in-depth guide to STCs on our learning centre.)

The Victorian government issues Victorian Energy Efficiency Certificates. These work similar to STCs, and also give you a point-of-sale discount.

The Victorian Solar Homes Program can entitle you to up to $1,000 off the cost of a system, but you’re only able to claim this once. If you need to replace your existing heat pump, this won’t be an option. If you’d like to learn more about the Solar Homes Program, check out our article here.


There’s not really a standard price for hot water heat pumps, only a range. What you pay for, mostly, is the quality of the technology. More expensive systems will last longer and run better, but their price might put them out of reach for some. Cheaper systems might be more affordable upfront but will cost more in the long run.

Premium heat pumps have a lot going for them. The one big downside is that you can’t make money appear out of thin air – so, if it’s out of your budget, then it’s out of your budget.

You can choose to go for a cheaper system you can afford today, but we recommend holding off. If you want to learn more about the reasons why, browse the other articles in our Learning Centre.

Topics: Hot Water, Heat Pump

Tags:    #Hot Water, #Heat Pump

Related Posts

How reliable are hot water heat pumps?

How do hot water heat pumps work?

Why G Store doesn't offer free heat pumps

Subscribe to our blog