Plenty of homeowners decide on a heat pump long before they understand what the switch involves. The unit on the wall is only one part of the job. How well the house holds its heat, the state of the radiators and where the hot water will be stored all shape how the system performs once it is running.
Doing some groundwork before an installer visits makes the survey more useful. It also makes the quotes you receive easier to compare.
Start With How Your Home Loses Heat
A heat pump works best when it can run steadily at a lower temperature than a typical gas boiler. That suits homes that keep their warmth well. A draughty house can still use one, but the system may need to be larger, and larger usually means dearer.
Before anyone arrives, walk round the house and take an honest look. Check the depth of loft insulation, whether the walls are cavity or solid, and how old the windows are. Gaps around doors and loft hatches are cheap to fix and make a noticeable difference.
Knowing where the weak spots are helps you understand the heat loss figures an installer gives you, and it shows where a modest spend on energy efficiency could reduce the size of system you need.
Look Closely at Your Radiators and Pipework
Because a heat pump runs at a lower flow temperature, each radiator gives out less heat than it would with a boiler running hot. Some rooms may need a larger radiator, or a double panel in place of a single, to stay comfortable.
A good surveyor will work through the house room by room and tell you which radiators can stay and which need upgrading. It helps to note any rooms that already feel cold, since those are likely candidates.
Old, narrow microbore pipework can also limit how much warm water reaches each radiator. If your heating system has been patched together over the years, mention it early so it is accounted for in the design.
Plan Space for Hot Water and the Outdoor Unit
Most heat pump installations need a hot water cylinder, because the system heats a stored tank of water and does not produce it on demand like a combi. If you currently have a combi boiler and no airing cupboard, you will need to find room for one.
Common spots include:
- A landing or bedroom cupboard that can be enlarged
- Part of a loft, if the structure allows it
- A utility room or garage close to the existing pipework
The outdoor unit needs a clear, level spot with good airflow and enough space for an engineer to service it. Think about neighbours, windows and noise, and keep in mind that rules on placement can vary, so ask your installer to confirm what applies to your property.
Understand the Grant Before You Budget
In England and Wales, the Boiler Upgrade Scheme offers a grant towards an air source or ground source heat pump. The installer applies on your behalf, and the eligibility criteria cover things like the type of property and the system being replaced. Scotland runs its own support through separate schemes.
The grant is deducted from your quote, so the figure you pay is lower than the full installation price. Rules and amounts can change, so check the official government page before you commit.
When you start setting a budget, it helps to read a realistic breakdown of heat pump prices, so the quotes you receive land in context. You will then find it easier to see which extras are included and which are not.
Think About Running Costs and Your Tariff
How much a heat pump costs to run depends on how efficiently it is designed and how you use it. A well set up system running at a low flow temperature can keep energy bills sensible, while a poorly designed one can disappoint.
Some energy suppliers now offer tariffs aimed at households with a heat pump installed, with cheaper rates at certain times of day. It is worth reviewing yours once the system has settled in.
Moving from gas to electricity will generally lower the carbon emissions from heating a home, and that benefit grows as the grid gets cleaner.
Choose an Installer Who Designs the System Properly
The quality of the design matters as much as the equipment. A reputable installer should carry out a proper heat loss calculation, size the unit to suit your home and explain how the controls work. For the Boiler Upgrade Scheme, the installer must be MCS certified.
Useful things to ask at the survey:
- How the heat loss figure was worked out
- Which radiators need replacing and why
- What flow temperature the system is designed to run at
Clear answers to these questions are a good sign. If an installer quotes without visiting, or cannot explain their sizing, keep looking.
Final Thoughts
Preparing for a heat pump is mostly about knowing your house. Once you understand how it loses heat, where hot water will live and what your radiators can cope with, the survey becomes a far more useful conversation.
Take your time, compare more than one quote and make sure the pump installation is designed around your home.
