Skip to main content
Heating your home

Cascaded heat pumps


  • A low carbon heating system
  • Suitable for properties with high heating demands
  • Able to maintain comfort during very cold weather

If you live in a larger property where a single heat pump can’t meet your heating and hot water demands, you may be interested in using a cascaded control system for multiple heat pumps.

What is a cascaded heat pump system?

A cascaded heat pump system allows more than one heat pump unit to work together to meet a property’s heating and hot water requirements.

These separate heat pump units can be designed to operate at the same time, for different tasks (ie one for heating, the other for hot water), or they can share the property’s heating and hot water demand between them.

How does a cascaded heat pump work?

Cascaded heat pumps only have a single control panel to manage the installation. When it’s warmer outside, only one heat pump needs to operate to heat the property efficiently. As it gets colder, the second unit may be needed to supply either hot water or extra help with heating, if required.

By having only one control system, the heat and hot water requirements can be managed and split across the two heat pumps in such a way that they always operate as efficiently as possible. Sometimes this might mean one is providing the heating duty while the other provides domestic hot water – at other times both might only provide heating, or one may be switched off entirely.

Why would I need a cascaded system?

If you have a large house, it’s possible your electricity supply might not be able to deliver all the heating energy you need using a single heat pump. Cascaded heat pumps overcome this problem and can be an ideal heating solution for larger homes.

Most houses in the UK have what is described as a “single phase” electricity supply. Bigger commercial buildings have “three phase” electricity supplies, enabling them to use more electricity and larger heat pumps.

Single phase domestic heat pumps are generally designed to only deliver a maximum of around 12-14kW of heating power. If you live in a house with a high heat demand, a single heat pump might not be able to provide heating all year round which is when you may benefit from a cascaded heat pump system. Hybrid heat pumps are another possible solution for buildings with high heat demands on single phase power supplies, as they use a back-up boiler or other heating source to make up any shortfall in extremely cold weather.

Your installer will advise on what the best solution might be for your property home. There could be multiple ways to meet your heating needs so it’s a good idea to speak to more than one installer for recommendations.

Last updated: 9 March 2022