Quick answer: Heat pumps do work in older homes. The best for a period house are R290 units that reach 70 to 75°C, such as the Grant Aerona 290, Mitsubishi Ecodan R290 and NIBE S2125. Design for 50 to 55°C flow, where they post SCOPs of 3.3 to 3.8 and beat gas. At 65°C, published figures fall to about 2.8 to 3.3, from level with gas to about 15% cheaper.
We haven’t tested any of these units. This guide compares manufacturers’ published datasheets, government trial data and grant rules, all checked on 25 September 2026.
Do heat pumps work in older homes?
Yes. The government-funded Electrification of Heat trial installed 742 heat pumps, 163 of them in homes built before 1945, and concluded that a heat pump shouldn’t be ruled out on a home’s age alone (Energy Systems Catapult, December 2024). It found no significant difference in heat pump performance by house age.
It wasn’t easy everywhere. Pre-1919 homes were the hardest, because many had heat losses bigger than the heat pumps available to the project, and the insulation needed to shrink them cost too much within its budget. So age isn’t the barrier. Heat loss and radiator size are.
Why flow temperature decides everything
The radiators in an older house were sized for a boiler running hot. Drop the water temperature and each radiator gives out less heat, so some rooms never warm up. There are two ways out: run the heat pump hotter, or make the heat loss smaller and the radiators bigger.
Running hotter costs you efficiency. Samsung’s 8kW EHS R290 is typical: an MCS-listed SCOP of 4.66 at 35°C flow, 3.41 at 55°C and 2.89 at 65°C (datasheet). Every heat pump follows the same curve. Our guide to flow temperatures and radiator sizing explains the physics.
High flow temperature heat pumps compared
| Model | Max flow temperature | SCOP at 55°C | Higher-temperature figure | Sizes |
|---|---|---|---|---|
| NIBE S2125 | 75°C; 65°C at -25°C outside | 3.70 to 3.80 | Cold-climate SCOP at 55°C: 3.20 to 3.40 | 8, 12kW |
| Grant Aerona 290 | 75°C | 3.33 to 3.74 | Not published | 4 to 15.5kW |
| Viessmann Vitocal 150-A / 151-A | 70°C down to -10°C outside | 3.51 to 3.61 (4 to 8kW) | Not published | 2.1 to 14.9kW output |
| Samsung EHS Mono R290 Gen 7 | 75°C | 3.41 to 3.51 (MCS) | 2.81 to 2.93 at 65°C (MCS) | 5 to 16kW |
| Mitsubishi Ecodan R290 | 75°C | 3.38 to 3.51 (MCS; 5kW, 8.5 to 12kW) | Not published | 5 to 12kW |
| Octopus Cosy 6, 9, 12 | 70°C | 3.4 to 3.9 at 50°C | 2.8 to 3.3 at 65°C | 5.6 to 11.2kW at -5°C, 50°C flow |
| Vaillant aroTHERM plus | 75°C | 3.06 to 3.63 | Not published | 3.5 to 12kW |
| Daikin Altherma 3 M (R32) | 65°C | 3.28 to 3.35 | No headroom above 65°C | 4 to 8kW |
Every propane unit in this table reaches 70 to 75°C, so the high-temperature question is largely settled. What separates them is efficiency at the temperatures you’ll actually run. Of these, only Samsung and Octopus publish a figure at 65°C; for the others, ask the installer for one.
The break-even point against gas
Under the October to December 2026 price cap, electricity costs 26.32p/kWh and gas 7.97p/kWh, so a unit of electricity costs 3.30 times a unit of gas. A gas boiler running at 85% seasonal efficiency, the figure Octopus uses in its own savings claims, turns that into a break-even SCOP of about 2.81. Above that, the heat pump is cheaper per unit of heat. Below it, gas is.
At 55°C, the units above post 3.06 to 3.80, between 9% and 35% better than break-even. At 65°C, Samsung’s 2.81 to 2.93 is level with gas. Take an older three-bed needing 15,000kWh of heat a year, our illustrative figure:
- Gas boiler at 85%: about £1,406 a year, plus £108 in gas standing charges if heating is the only thing you use gas for.
- Heat pump designed for 55°C at SCOP 3.5: about £1,128.
- Heat pump run at 65°C at SCOP 2.85: about £1,385.
Designing for 55°C saves around £280 a year on energy against gas. Running at 65°C saves about £20. So don’t keep every original radiator unchanged if swapping a few would get you to 55°C. The arithmetic behind SCOP is in COP and SCOP explained.
How to get the flow temperature down
- Insist on a room-by-room heat loss calculation to MCS’s MIS 3005 standard. It shows which rooms fall short at 50 or 55°C. See our heat loss calculation guide.
- Upsize only the radiators in those rooms. In most older houses that’s a handful, not all of them. Our radiator guide explains how to tell.
- Do the cheap fabric work first: loft top-up, draught-proofing and cavity fill where there’s a cavity. Solid wall insulation is expensive and optional. Our guide to insulating before a heat pump shows the order.
- Ask for the expected SCOP at your design flow temperature, in writing. Be wary of any quote that specifies 65°C to avoid changing radiators, then prices running costs on a 35°C SCOP.
Our picks for older homes
Best overall: the Grant Aerona 290. Five sizes up to 15.5kW mean an installer can match it to a draughty farmhouse or a small terrace, and four of the five post 3.62 or better at 55°C. Octopus fits the 15.5kW model for larger or harder-to-heat homes (Octopus).
For a big house with high heat loss, the NIBE S2125 12kW has the best 55°C figure we found at 3.80, and it’s the only unit here with published cold-climate SCOPs. Octopus pitches its Cosy 12 at larger or older homes with a heat loss up to 11.2kW.
For a terrace with a neighbour’s window close by, Grant’s 4kW has the lowest published sound power here at 48 dB(A), against 54 to 56 dB(A) for the Mitsubishi Ecodan R290. Both are rated at about 40 dB(A) at one metre.
If you genuinely must run at 65°C, buy a Samsung or an Octopus Cosy, because they tell you what you’ll get there and you can budget for it. And avoid R32 units that stop at 65°C, such as Daikin’s Altherma 3 M, if you’re keeping original radiators. The full field is in our heat pump brands ranking.
Off-gas older homes: oil, LPG and the £9,000 grant
If you’re in rural Devon, Cornwall or anywhere else off the gas grid, you’re in good company. Of the 93,364 grants paid up to August 2026, 17% replaced oil heating and 49% went to rural homes (DESNZ statistics). In England and Wales, a home heated by oil or LPG with no mains gas connection can get £9,000 instead of £7,500 on applications from 21 July 2026 to 31 March 2027. Our oil boiler replacement guide covers the switch.
Near the coast, check the corrosion terms. NIBE’s 7-year warranty requires protective coating within a kilometre of the shore (NIBE), and Mitsubishi sells coastal-protection versions of the Ecodan R290.
Listed buildings and conservation areas
England relaxed the permitted development rules for heat pumps on 29 May 2025, removing the old one-metre boundary rule, but the unit still has to pass the MCS 020(a) sound calculation. If your home is listed, expect to need listed building consent, and in a conservation area there are extra limits on where the unit can go. Read our guides to listed buildings and conservation areas before you commit.
Grants for older homes
There’s no grant just for older homes, but the main schemes all apply:
- England and Wales: the Boiler Upgrade Scheme gives £7,500 towards an air or ground source heat pump, with no income test. Your MCS-certified installer applies, takes it off the quote and has three months from the voucher to fit an air source unit. The rule that loft and cavity insulation had to be done first ended on 8 May 2024, and a valid EPC is no longer strictly required. Hybrid systems don’t qualify. Our Boiler Upgrade Scheme guide has the details.
- England, lower incomes: the Warm Homes: Local Grant covers homes rated EPC D to G with household income under £36,000 or on means-tested benefits, up to £16,600 for energy efficiency and £16,600 for low-carbon heating.
- Scotland: a Home Energy Scotland grant of £7,500 for a heat pump, plus £1,500 in rural areas, and up to £7,500 more as a loan. See our Home Energy Scotland guide.
- Wales: the means-tested Nest scheme as well as the Boiler Upgrade Scheme. Northern Ireland has no Boiler Upgrade Scheme; see our Northern Ireland guide.
- Everywhere: 0% VAT on installed heat pumps and insulation until 31 March 2027.
The best heating system for an old house
For most older houses, a propane air source heat pump designed to run at 50 to 55°C. In our example it runs about a fifth cheaper than gas at the October to December 2026 price cap, it attracts £7,500 in England and Wales, and capping off the gas saves the standing charge too.
Keep a gas boiler only if planning or listing rules stop you siting an outdoor unit, or if the heat loss is beyond the largest single units here, around 16kW, and you can’t bring it down. Big rural plots can also look at ground source; our air vs ground source comparison covers it. When you’re ready, request a free quote: up to three approved installers who cover your area may contact you. No charge, no obligation.
This guide is based on manufacturer datasheets, the Electrification of Heat trial, DESNZ and GOV.UK grant data and the Ofgem price cap, all checked on 25 September 2026.
FAQs
Can you put a heat pump in a Victorian house?
Yes. The government-funded Electrification of Heat trial fitted 163 heat pumps in homes built before 1945 and found performance didn’t differ significantly by house age. Victorian homes need a proper heat loss survey, a unit that reaches 70 to 75°C and usually a few bigger radiators.
Do I have to replace all my radiators?
Rarely. A room-by-room survey usually shows a handful of rooms fall short at 50 to 55°C. Upsizing those few radiators lets the heat pump run at a SCOP of around 3.4 to 3.8 instead of about 2.8 to 3.3 at 65°C.
What is the best heating system for an old house in the UK?
For most, an R290 air source heat pump such as the Grant Aerona 290 or Mitsubishi Ecodan R290, designed for 50 to 55°C flow. It beats gas on running cost at the October to December 2026 price cap and attracts a £7,500 grant in England and Wales.
Is there a heat pump grant for older homes?
Not specifically. Older homes get the same £7,500 Boiler Upgrade Scheme grant in England and Wales, or £9,000 if heated by oil or LPG with no mains gas until 31 March 2027. Scotland, Wales and Northern Ireland have their own schemes.
Is a heat pump worth it in a poorly insulated home?
Often, if you do the cheap insulation first and design for 55°C or lower. Insulation is no longer a grant condition, but every kilowatt of heat loss you remove lets the system run cooler and cheaper.
Get quotes for either, or both
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