Ecospring 300L Heat Pump Hot Water Cylinder

We will be doing a new series in our monthly blogs, reviewing products from our range and providing you with the information you need to help you make an educated decision when selecting a hot water system for your home.

Have you heard of the Ecospring ES300? This is a 300L heat pump hot water cylinder unit designed to provide you efficient water heating but utilising a heat pump system to heat your water. How does heat pump water heater work?

The basic process is as follows. A fan draws in air through an evaporator. Thermal energy from the air is transferred to a liquid refrigerant causing it to change into a gas.The refrigerant gas is then drawn into a compressor which increases its pressure and thus increases the temperature. A condenser or heat exchanger then transports the hot gas refrigerant around the outside of the water tank. This heats the water inside the tank and the gaseous refrigerant transforms back into a liquid. The pressure of the refrigerant is reduced as it goes through an expansion valve and returns to the evaporator for the process to start again.

ecospring_es300_hot_water_heat_pumpSo why is the Ecospring ES300 a good option for a heat pump water heater?


The Ecospring 300L heat pump water heater is a very efficient water heating unit, with a large storage capacity for ensuring you have a large amount of hot water on hand for when you need it. Being large enough for a 3+ person household, this unit is an excellent choice for families and larger homes. It also has the ability to switch to e-Heater mode, which means it runs like a normal electric hot water cylinder, without the heat pump. This is useful in cold conditions, where this is not enough heat in the air for the heat pump to work efficiently.

The Ecospring ES300 is a bit more expensive than similar competitor units, so you may have to pay a bit more for your initial investment, but you will also be getting a bit more for your money. E.g: Unlike similar models with 2 KW elements, the Ecospring includes a 3KW immersion element which kicks in at a predetermined temperature to ensure quick recovery when high usage occurs. We highly recommended you put specs next to each other when comparing products and then ask yourself the question “why?”. It’s good to make an educated decision with such investments.

On the Ecospring ES300, the heat pump is built into the cylinder, making it compact and affordable in comparison to buying both parts separate, like you would with a traditional heat pump unit. It also contains the following features:

Advanced Controls. The advanced EcoSpring Heat Pump Hot Water Cylinders allow you to control your own hot water requirements with an easy to use Control Panel.

Hybrid Mode. While the unit uses the heat pump as its primary means to heat the water, the standard electric elements will activate if the ambient air temperature is below -7°C.

e-Heater Mode. This mode shuts off the heat pump and only uses the electric elements to heat the water, just like a standard electric water heater. eHeat mode allows for operation in colder situations (less than -7°C) where the heat pump would not function ideally.

Indoor/Outdoor installation. Designed to withstand weather, this unit can be installed inside or outside. It has a standard electrical connection, standard cold water inlet and hot water outlet.

What is a COP value?

COP – Coefficient Of Performance – Is the measurement of efficiency of refrigerant systems including heat pumps.The COP value is the ratio between energy usage of the compressor and the amount of useful heat extracted from the condenser in a heat pump. A high COP number represents a high efficiency. For a heat pump, a COP of 4 means that 1 kW of electric energy is required to produce 4 kW of heat at the condenser. On the evaporator side, 3.0-3.5 kW of heat is extracted. The additional heat is produced by the compressor. For a heat pumps, COPh is generally used as it is a slightly different measurement to that of a refrigerant system. In this abbreviation ‘h’ means heating.

The COP rating in (W/W) of the Ecospring ES300 is:

Economy 3.60
Hybrid 3.60
E-heater 1.00

pdf Ecospring 300 manual PDF


What are the biggest challenges for heat pump hot water cylinders?

While these units are very efficient, the best of these units are more expensive than electric units and can be more prone to failure than electric water heaters. Installation is also trickier, as they need a supply of warm air to be able to run efficiently. This can be a disadvantage in colder climates and during the winter.

Cold Weather Performance

Heat pump cylinders are not an optimal choice for homes in cold climates. Since they draw heat from the surrounding air, their benefit is marginal at colder temperatures.

Indoor Installation Challenges

Because of how these cylinders work, indoor installation is not ideal if it is not a split system. The problem being that the heat pump extracts the heat from the air around it, which means it exhausts cool air. if the unit is installed in an enclosed area, it will cool that air very quickly and keep feeding on it’s own colder air. This means that the heat pump will have less heat to extract from the surrounding air, slowing down the heating process, wasting power and extending the run time of your heat pump every time it runs to heat your water.

A heat pump needs a good air flow around it, it needs to be able to get fresh warm air in on one side and somewhere to push the cold air away. With split systems, the heat pump can be installed outside and the tank inside, and they work very well in this way.


They do make a low humming sound similar to an air conditioner while operating. This should be taken into account when deciding where to install the unit.

Repair Costs

It is common with heat pump cylinders that you will be facing repairs very soon after the warranty expires, which is coincidentally around the time your investment begins to pay itself off.


At this point you will no doubt be asking if it is worth investing in this hot water heat pump and what the pay off rate will be. This will depend on your needs and installation. If you need big storage but don’t use a lot of hot water regularly, a heat pump water heater is worth the investment as it can save you up to 65% or even more on energy costs. This means a quick rate of payback for a superior water heating system. You will not be left without hot water any more so than what you would be with a regular electric cylinder, if you are a heavy hot water user.


A heat pump water heater is definitely a good choice for high hot water users, providing an immediate ROI, with the water heating systems being up to 300% more efficient than conventional water heating systems. And the Ecospring ES300 is no back bencher. If you are looking for a heat pump water heater that is extremely efficient and will make sure you will always have hot water waiting for you, you can’t go wrong with the Ecospring ES300.

Alternative Product ComparisonBosch_compress_3000_hot_water_heat_pump

The Ecospring ES300 is similar to the Bosch 3000 heat pump hot water cylinder unit. The Bosch 3000 unit is an excellent German made unit, however it is made with German conditions in mind. Due to their cold winters, this unit has been designed to run effectively in very cold weather. While this is an excellent positive, and means that it needs to work less to achieve a high kW output in New Zealand where it gets no where near as cold. However, it only comes in 2kW element configuration. It takes a long time to heat 300L of water with a 2kW, and if hot water is in high demand, this unit might not keep up and your teenagers may end up having cold showers. This means that while you will save on energy costs, but it will require a change of lifestyle to adapt to using this unit.

Bosch 3000 Features

• Highly efficient heat pump – reduces energy use by up to 65% when compared to conventional electric storage
• Eligible for generous government rebates
• Smart Controls to:
• Allow user to set operating time systems
• Operate with PV solar electric systems to optimise energy efficiency
• Low noise performance and additional noise reduction timer function
• Designed for easy and low-cost install and servicing
• The heat pump operates from -7°C to 40°C, delivering energy efficient hot water even in colder climates

We currently have a deal on our Ecospring 300L Hot Water Heat Pump with free shipping. Have a look at our online store and buy yours today!