Heat pump unit
We’ve based installation on choosing a standard air-to-water heat pump .
The installer will install the heat pump unit outside of your home. These external units vary in size but may be as much as 1 metre by 1.5 metres. That’s around the same space as two wheelie bins.
They may need to build a platform for the unit to stand on, if the existing ground covering isn’t suitable. They might dig a soakaway if there is no suitable drain.
Installing a ground source heat pump? Your installer will need to dig trenches and lay pipes in your garden, or drill boreholes for vertical pipes, to extract heat from the ground. These pipes are then connected to the heat pump unit itself, which is usually fitted inside the home rather than outside, though it could be in an outhouse or garage.
Hot water cylinder
Heat pumps don’t provide hot water on demand like a combi boiler, so you’ll need another way to provide hot water. Usually your installer will fit a hot water cylinder to store water that’s been heated by the heat pump ready for when you need it. If you already have a hot water cylinder it will probably need to be replaced with one suitable for the heat pump.
If you don’t have room for a hot water cylinder, your installer can suggest other options available to you. These might include:
- installing a heat battery (like a hot water cylinder, but smaller)
- adding one or more instant hot water heaters (eg under a kitchen sink)
Radiators
Heat pumps typically send hot water to radiators at a lower temperature than an equivalent fossil fuel central heating system, often between 35-45°C . But you can still heat your home effectively with a heat pump by:
- running the heating for longer.
- increasing the size of your radiators.
Larger radiators have a larger surface area, so they emit more heat into the room even though the water temperature is lower. This doesn’t necessarily mean you need to give up more wall space, though:
- It may be that your existing radiators are already big enough – your installer will tell you once they have calculated your heating requirements.
- You can upgrade single panel radiators to double (K2) or triple (K3) panels to increase their surface area without taking up extra wall space.
- You may be able to fit underfloor heating instead of radiators.
Plumbing and wiring
The installer will connect the heat pump and hot water cylinder to your existing heating and hot water system. They’ll also replace any pipework that needs to be upgraded. They should also flush out the system. This is to get rid of any sediment that has built up over the years or has been introduced while plumbing in the new equipment.
The heat pump will also need to be connected to your electricity supply. Many installers will bring in a separate electrician for this, who will also connect the controls.