Air source heat pumps

What a heat pump does that an air conditioner does not

Both move heat rather than burn fuel, and a modern split air conditioner is already a heat pump running in both directions. The difference is what they heat. A split heats the air in one room. An air source heat pump heats water, so it feeds your radiators or underfloor pipework and your hot water cylinder, and replaces the boiler rather than sitting alongside it.

That is why the two are quoted so differently. A split is an appliance on a wall. A heat pump is a change to the heating system of the whole property, and the pipework, the radiator sizes and the insulation all decide whether it performs.

Monobloc or bibloc

• Monobloc: the whole refrigerant circuit is sealed in the outdoor unit and only water pipes run into the house. Simpler and quicker to fit, and no F-Gas handling on site. The water pipework outside has to be protected against freezing.
• Bibloc, also called split: refrigerant runs to a small indoor hydro unit that holds the heat exchanger. Keeps the water inside the building and tends to hold output better in a cold snap, but it is a refrigerant circuit, so it needs an F-Gas registered engineer to commission.
• Which one suits a property depends on where the unit can stand, how cold the site gets and how much room there is indoors. Tell us the property and we will say which of the two we would send.

The Boiler Upgrade Scheme, and the part people miss

England and Wales run a government grant towards an air source heat pump under the Boiler Upgrade Scheme. Scotland runs its own scheme through Home Energy Scotland instead.

Here is the part that catches people out: you cannot claim it yourself. The grant is applied for by the installer, and only an MCS certified installer can do it. It is paid to them and comes off your invoice. Buying the equipment first and looking for a fitter afterwards is the one order that can cost you the grant, because if nobody MCS certified will take on a machine they did not supply, there is no application to make.

So line up your MCS installer before you order anything. We are happy to talk to them directly about the unit.

Grant amounts and conditions change, so check the current figure on gov.uk rather than taking a number from any supplier, including us.

What to have ready before you ask for a price

• Roughly what you heat now and what it costs you.
• The floor area, and whether you have radiators or underfloor.
• Whether there is a hot water cylinder already, and where it sits.
• Where an outdoor unit could stand, with room for air to move around it.
• Your EPC, if you have one. It matters for the grant.

We supply, we do not install

Same as the rest of our range. We sell you the equipment and deliver it, and your engineer fits and commissions it. On a heat pump that split matters more than on an air conditioner, because the grant, the MCS paperwork and the system design all sit with the installer.

Send us the details of the property and we will come back the same day with what we would supply and what it costs.