Domestic GSHP FAQs

Very good. On-site electricity generation can be used to power some of the heat pump demand. Solar thermal can be used to supplement or replace heat pump in the summer to save money.

Same as gas boiler. Room temps are set by building regulations and the heat pump delivers this in the same way as a gas boiler.

Gas boiler c.£2500. ASHP c. £8,000. GSHP c. £20,000. Totally dependent on heat load though.

It’s the same philosophy as gas or water supply. Some houses need more water and some need more gas. It is paid for by gas and electric metering. Heat meters are used for the same purpose.

You need to ask. Also heat loss calcs and Connect and Notify (DNO) is required as part of the MCS process so your installer should do that to remain MCS compliant.

This depends on the install.

If one heat pump per house operating on a shared ground loop, electricity used to power the heat pump is usually organised and paid for by the homeowner. The heat pump can be metered or the power to the heat pump will be metered via your electricity meter just as any other appliance in your home.

If a central heat pump supplying heat to multiple homes via a heat network, the owner of the heat network will charge the homeowner a heat price which includes the cost of running the heat pumps and network. You do not pay the electricity directly other than electricity for other appliances in your home.

Hot water is priority for a heat pump. Usually a 3 port valve is used to ensure the hot water cylinder is kept topped up. If the cylinder drops in temperature (e.g., having a bath or shower), the heat from the heat pump is diverted temporarily from the heating circuit to the cylinder to ensure you don’t run out of hot water. The sizing of the cylinder and the coil within is very important – make sure you ask your installer about this.

Cheaper to install in a new build as there is nothing to strip out and the pipework and radiators will have been designed specifically for low temperatures. The hot water cylinder will also be specifically designed and installed within the new build.

Depends on house size and heat demand. Anything from 3kW for a small flat to 100kW+ for a stately home!

We have two heat pump manufacturers in Britain (domestic heat pumps). Others are built all over the world.

If the existing pipework can be reused, it will be left in-situ. Ideally, the flow and return pipes from/to your boiler will be used to hook up to your heat pump, albeit with new pipework to the hot water cylinder. But there may be a requirement to change the pipework to fit to the heat pump or possibly to make the pipework bigger. But the pipework around your house should be OK – unless the installer calculates it needs to be upgraded.

Should be very low, almost like your fridge freezer humming.

Yes – there are heat pumps capable of both heating and cooling. Heat pumps are actually chillers in reverse. You will need to make sure to select a heat pump capable of this in the first place – ask your installer. And you need to make sure your emitters are capable of emitting cool as well as heat. Condensation on pipework can be a problem and normal radiators are not a good type of cooling emitter. Convector radiators are good.

You will only need single phase electric supply up to 28kWth heat pump. Depending on how full the distribution board is in your house, you may need an upgrade. It is a question to ask your installer and/or surveyor. The installer is also responsible for the Connect and Notify process with the DNO, who will advise if there are local issues with electrical connections.