Energy & efficiency
Heat pumps: is your home actually ready?
A heat pump heats a well-prepared home beautifully and a leaky one expensively. Before anyone quotes you, run this readiness check across insulation, radiators, space and paperwork. Sometimes the right answer is to insulate first and fit the pump later, and a good installer will say so.
By the Tickover team · Published 25 February 2026 · 4 min read
How a heat pump changes the rules
A gas boiler blasts radiators at 70°C or more and papers over a house’s sins. An air source heat pump works at 35–50°C, using a little electricity to move a lot of heat from the outdoor air indoors. At those gentler temperatures the same radiators give off less heat, so the house has to keep more of what it gets, and some emitters usually need to grow.
That is also where the famous efficiency comes from: moving heat rather than making it returns roughly three units of warmth for every unit of electricity across a year. The catch is that insulation, radiators, pipework and cylinder have to be designed as one system. Hence the readiness check, which matters more than any brochure.
The readiness checklist
Ready, or nearly, if you can tick most of these
- Loft insulation at or near 270mm (top it up first if not)
- Cavity walls filled, or solid walls with a costed plan
- Double glazing in most rooms
- Outdoor space for the unit, with airflow and drainage
- Room indoors for a hot water cylinder, airing-cupboard sized
- The house stays warm with boiler flow set to 50°C (see below)
- A surveyor offering room-by-room heat loss sums, not a glance
The free test your radiators can sit right now
Set your boiler flow temperature to 50°C in cold weather and live with it for a week. If the house stays comfortable, your radiators are already close to heat pump sized. If a couple of rooms lag, those are the radiators a good installer will quote to upsize, often two or three of them rather than a whole-house swap.
Watch out for microbore pipework (pencil-thin copper, common in 1970s–1990s builds). It can limit flow at low temperatures, and a proper survey will check it rather than discover it on install day.
| Gas boiler | Air source heat pump | |
|---|---|---|
| Radiator water | 65–75°C typical | 35–50°C |
| Running pattern | Short, hot bursts | Long, low and steady |
| Space needed | A cupboard | Outdoor unit plus cylinder |
| Who installs | Gas Safe registered engineer | MCS certified installer |
What it costs, and the grant
At the time of writing, the Boiler Upgrade Scheme takes £7,500 off an air source heat pump installation in England and Wales, claimed through an MCS certified installer rather than by you. Quotes vary with how much radiator and cylinder work rides along, which is exactly what the readiness work shrinks.
Heat pump money, as a guide
Air source pump installed
Before the £7,500 grant
New combi, for comparison
Like-for-like swap
Typical UK ranges, mid-2026, as a guide only. Your home, your area and the job itself all move the number — always compare real quotes.
Take the grant off and most heat pump installs land somewhere between £500 and £6,500. Where you fall in that spread depends mostly on the state of the house, not the badge on the unit.
When the answer is “not yet”
If the survey shows high heat loss, spending five figures to heat the sky is the wrong move, grant or no grant. Work through the bill-cutting order first, then come back to the pump with a smaller heat demand and a smaller quote. An installer who tells you to insulate first is one to keep.
Meanwhile, keep the boiler behaving. A heat pump bought in a panic after a December breakdown is rarely the well-designed one. And if your hesitation is the climate, park it: heat pumps hold up in a British winter when sized properly, which is the whole game.
Want a second opinion before you spend?
Ask Tickover Advice whether your home is heat pump ready. The property-aware draft is free, and from £49 a chartered professional verifies and signs the answer before you commit thousands.
Quick answers
Do I need to replace all my radiators for a heat pump?
Usually not all of them. A proper heat loss survey works room by room, and in many homes only two or three radiators need upsizing while the rest stay. Homes that already keep warm with a boiler flow temperature of 50°C often keep every radiator they have. Be wary of quotes that swap everything without measuring anything.
Can I get the £7,500 heat pump grant?
At the time of writing, the Boiler Upgrade Scheme offers £7,500 towards an air source heat pump for most homes in England and Wales. It is claimed through an MCS certified installer, who takes it off your bill rather than you applying separately. Funding rules change, so confirm the current position before signing.
Will a heat pump work with my combi setup?
It replaces the combi rather than joining it, and you gain a hot water cylinder, because heat pumps heat water steadily rather than instantly. That cylinder needs a home, usually an airing cupboard or utility space. If you have nowhere to put one, say so early, because it shapes the whole system design.
Is my home too old for a heat pump?
Age matters less than heat loss. Plenty of Victorian homes run heat pumps happily after insulation and a few larger radiators, and plenty of newer houses are ready today. The survey numbers decide it, not the year on the deeds. If the numbers come back poor, insulate first and reassess in a year.
This guide is general information for UK homes, not advice about your specific property. Anything involving gas must be done by a Gas Safe registered engineer, and notifiable electrical work by a qualified electrician. If you smell gas, call the National Gas Emergency line on 0800 111 999. If you’re ever unsure, stop and get a professional in — that’s exactly what Tickover is for.
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