Best Hot Water Cylinders for Heat Pumps in 2024: Expert Guide

In this guide we will look at which brand of hot water cylinder is best designed for efficiency with a Heat Pump, and what alternatives to energy-efficient hot water cylinders there are as well.

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With energy costs rising year on year, you want efficiency to be optimised so that you can lower your bills as much as possible. Choosing the right heat pump cylinder can make a significant difference to the efficiency of your system. In this guide, we explore the best water tanks for heat pumps on the market, with due consideration to the efficiency, capacity, and performance. If you want to talk to one of our experts then book a call and they will be able to guide you to the best solution for your home.

What Is a Hot Water Cylinder for a Heat Pump?

A direct hot water cylinder stores hot water generated by a heat source, such as a boiler or a heat pump system. Be careful to choose a cylinder that is specifically for heat pumps, as they do differ and we will explain why in this article. Some manufactures make this more challenging that it needs to be by calling their range of boiler cylinders by the same name as the heat pump cylinder range, so you do need to be vigilant.
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The water cylinder ensures your home has a steady supply of hot water for baths, showers, and heating.
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The direct hot water cylinders used in air source heat pump systems are different to those used with boilers. This means that if you have a System or Regular boiler in your home, that already utilises a hot water cylinder, it will likely need to be replaced if you upgrade from a boiler to a heat pump.

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The hot water cylinders that are compatible with heat pumps have a heat exchanger (coil) with a larger surface area than those of a gas boiler (where the flow temperature of the water passing through the cylinder coil, to heat the direct hot water, is much higher). The larger surface area of the heating coil allows more heat energy to be passed to the water in the cylinder, so it can be done at a lower temperature.

Key Factors to Consider When Choosing a Heat Pump Cylinder

Top Heat Pump Cylinders in 2024

Here are some of the best heat pump cylinders currently available from the heat pump manufacturers:

Ideal Logic Air Pre-Plumbed Cylinder

Seamless integration with the Logic Air Heat Pump, one of our favoured heat pumps, particularly in the R32 range. Read our review of the Ideal Logic Air here.

This cylinder is designed specifically to pair with the Logic Air Heat Pump, so the integrated buffer, the secondary pump etc. will all work in harmony with the heat pump unit, avoiding some of the losses in efficiency that you can get from hydraulic separation. The cylinder with integrated buffer works best where a retrofit will be disruptive and expensive as it can still make an efficient system with 10mm pipes to the radiators (tails), whereas a buffer isn't always advisable in all situations, because it can reduce efficiency in some systems. The Logic Air pre-plumbed cylinders without a buffer only go up to 200L, but these smaller cylinders also have the wiring centre already set up, which makes it very hard to make mistakes on the install. We love the way Ideal make commissioning the heat pump and cylinder as easy as possible for installers - it means customers can expect less problems after the install is completed.

‍Vaillant Unistor Heat Pump Cylinder

Maximum efficiency with Vaillant heat pump systems. We like the Vaillant aroTherm Plus, their flagship air source heat pump. This tailored compatibility ensures optimal efficiency, precise temperature control, and consistent performance. It is not an especially stand out cylinder, but Its advanced insulation, superior heat retention, and built-in smart technology integration make the Unistor a top choice for homeowners installing a Vaillant heat pump.

‍Mitsubishi Electric - Ecodan Cylinders

This offers comprehensive heating solutions with advanced control systems for the Ecodan heat pump range. Pre-plumbed with for an easy installation and performance without the need for customer intavention.

‍Daikin - Altherma Cylinders

Daikin Altherma cylinders feature innovative thermal storage technology and pair perfectly with Daikin heat pumps. Their smart grid compatibility, customisable settings, and low heat loss design ensure reliable, efficient performance year-round.

Why Choosing a Cylinder That Matches Your Heat Pump Manufacturer Often Makes Sense

When installing an air source heat pump, choosing a hot water cylinder that matches the heat pump manufacturer can be one of the most important decisions for ensuring long-term energy efficiency, system performance, and operational reliability. Here’s why it can often make sense to get the heat pump and cylinder from the same manufacturer:

Heat pumps and cylinders from the same brand are designed to work together, this means you can expect smooth communication between system components. This allows precise control of water temperature, flow rates, and heating cycles, resulting in a more efficient and balanced heating process.

Installers familiar with a specific brand can complete the installation faster and more accurately. Factory built compatibility minimises installation errors, resulting in reduced setup time and enhanced operational stability, especially where the cylinder is pre-plumbed (ie. Many of the components and surrounding pipework are already in place).

Many branded systems come with smart home integration, offering convenient app-based control and monitoring. For example, the Vaillant Unistor pairs with Vaillant’s VRC 700 Smart Control, enabling remote adjustments, energy tracking, and real-time performance monitoring.

Manufacturers often provide extended warranties for systems with all matching components. In addition, customer service and technical support are more equipped to provide remote support since the manufacturer understands the complete system setup, which makes troubleshooting more efficient.

When to Use a Specialist Water Cylinder Solution

Standard water cylinders are not always the best fit for every heating setup. Certain scenarios call for a different type of cylinder or a different solution altogether.  Here is when you might consider these options:

‍When Space Is Limited

You might consider the Sunamp Thermal Storage battery, here is an article where we review the Sunamp Thermino X-Plus. Given the compact size it works well for homes where space is at a premium.

Sunamp thermal storage units use advanced phase-change materials (PCM) to store heat in a compact design. This PCM then passes heat to the water that passes through the storage battery, which heats this water. They provide instant hot water with minimal space requirements.

‍You have Solar PV

The Sunamp Thermino X-plus is also designed to integrate with Solar PV directly, as well as a heat pump.

You have Solar Thermal

In order to integrate a heat pump with an existing solar thermal system, you need to make sure you have a twin-coil hot water cylinder.

A twin coil cylinder has two internal coils—one connected to the boiler or heat pump and the other linked to solar thermal panels. This design allows for dual-source water heating, making it perfect for households looking to reduce reliance on gas or electric boilers while maximising the use of renewable energy.

‍When Central Heating Is Handled Separately

A good solution would be an integrated heat pump cylinder, also known as a direct hot water heat pump. 

This is a good solution for homes that require hot water only while using a separate central heating solution.

Integrated heat pump cylinders are self-contained units with a built-in heat pump. Read our article to get a better understanding of how they work, as well as the pros and cons. They are ideal when homeowners want a standalone hot water system. They offer smart controls, modular designs, and energy-efficient heating.

Conclusion

There is no set rule for which cylinder will best suit your property or heating system. Hopefully this guide helps you to understand the options in different situations and help reduce energy waste, improve home heating performance, and simplify maintenance. Investing in the right system guarantees greater comfort, enhanced energy efficiency, and lower operating costs.

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