Is a heat pump worth it in the UK in 2026?

The short answer: it depends on two things. What fuel you currently heat with, and how insulated your home is. If you heat with oil, LPG, or old electric storage, a heat pump almost always pays back, even before the £7,500 grant is counted. If you heat with mains gas and your fabric is poor, the maths does not work at today's prices. If you heat with mains gas and your fabric is good, the answer is tight but increasingly workable. Everything else is detail.

The three-minute decision

There are essentially three situations you can be in.

Situation 1: off-gas (oil, LPG, old electric heating). Buy a heat pump. The running cost is 30 to 60 per cent lower than what you pay today, the £7,500 grant knocks a massive chunk off the install, and payback on the net cost is usually five to seven years. The only reason to wait is if your home is extremely badly insulated. Even then, insulation plus a heat pump is almost certainly a better life choice than a new oil boiler.

Situation 2: on mains gas, poor insulation. Do not buy a heat pump yet. Fix the fabric first. A heat pump running at a seasonal coefficient of performance (SCOP) of three or less into an under-insulated house is working harder than it should, you pay peak electricity rates for heat that is leaking out, and the saving versus gas at 2026 prices is negative. Insulation, then heat pump, in that order.

Situation 3: on mains gas, average or good insulation. The maths is tight. At the April 2026 Ofgem cap, gas is 6.72p per kWh and electricity is 24.67p per kWh. A heat pump needs to be about 3.7 times more efficient than the boiler it replaces just to break even on running cost, and the MCS fleet average is 3.2. So the savings are marginal in the narrow "just replace the gas boiler" case. The real argument in Situation 3 is about future prices, carbon, and the fact that you need to replace your boiler eventually anyway. See "when to decide" below.

The numbers behind it

Here are three worked examples using the same Ofgem prices that sit inside the calculator.

A 4-bed detached on oil, average insulation

Annual heat demand: around 18,000 kWh. Oil cost at 72p per litre and an 88 per cent-efficient boiler: about £1,470 per year. Heat pump running cost at a SCOP of 3.2 plus £200 service: about £1,590 per year. Honest answer: at 72p per litre, the running cost is roughly flat. Oil going back above 90p per litre (as it has been recently) flips it to a clear £400 to £700 saving per year. The grant and install advantages stand either way. The other thing oil households do not always price properly is the decarbonisation deadline on off-gas homes and the risk that oil prices spike every few years while electricity continues to trend down.

A 3-bed semi on mains gas, average insulation

Annual heat demand: around 12,000 kWh. Gas cost at the April 2026 cap: about £916 per year. Heat pump running cost: about £1,125 per year, including a service contract. Year-one saving: minus £209. The gross install is £11,500; net of the £7,500 BUS grant, £4,000. You do not pay back the £4,000 because running cost is higher. This is the honest answer. What changes it: gas prices rising, the 75 per cent gas-to-electric price ratio closing (the government has signalled moves here), or electricity going down via cheaper renewables and smart tariffs.

A 3-bed semi on old electric storage heaters

Annual heat demand: same 12,000 kWh. Electric running cost at the full day rate of 24.67p per kWh: about £2,960 per year. Heat pump running cost at SCOP 3.2: about £925 plus service equals £1,125. Year-one saving: about £1,835. Payback on the £4,000 net install cost is around 2.2 years. This is a no-brainer. If you currently heat electrically, get quotes this week.

What changes the answer

Three things affect how this calculation ages.

Gas prices. Mains gas has been cheaper per kWh than electricity for decades. Current policy signals (shifting environmental and social levies off electricity onto gas, pricing gas more honestly against its carbon cost) point to that gap narrowing. It does not need to close all the way; even a 15 per cent squeeze on the price ratio makes Situation 3 clearly work.

Electricity tariffs. The Ofgem cap is not the only price you can pay. On Intelligent Octopus Go, a decent share of your heat pump's daily running can happen on the 8p per kWh off-peak rate if you have a hot-water cylinder that pre-heats overnight. Cosy Octopus is built around heat pump schedules. These tariffs cut heat pump running cost by 15 to 30 per cent.

Insulation. The maths is more sensitive to insulation than people realise. Moving a 3-bed semi from average to good insulation drops heat demand by around 20 per cent. That is a 20 per cent saving on running cost, for both gas and heat pump, so the ratio does not shift, but the absolute cost drop is meaningful.

Grid carbon. UK grid electricity is already cleaner per kWh than mains gas on a carbon basis (207 grams per kWh versus 183 grams per kWh direct, though gas has methane leakage on top). By 2030 the grid will be roughly half current intensity. A heat pump bought today gets cleaner every year. A gas boiler bought today does not.

When to decide

The case for acting now:

The Boiler Upgrade Scheme is confirmed at £7,500, but grant levels and eligibility can change with each budget. Historical pattern: grants get more generous during launch phases and tighter once adoption hits targets.
Heat pumps are a mature product now. Installer quality varies enormously, but the best MCS-certified installers are doing reliable, low-temperature, high-SCOP installs.
Smart TOU tariffs that make heat pumps cheaper to run are at their most competitive in the current Ofgem cycle.

The case for waiting:

If your current boiler is under 10 years old and working well, there is no strong operational reason to replace it today. Replace at end of life.
If your home is in the "poor insulation" bucket, the money goes further on fabric first. That work has its own grant options.
If gas prices fall significantly (unlikely but possible), the gap widens again.

If the calculator shows a clear positive answer, act. If it shows negative or marginal, fix insulation, re-run it annually, and be ready to commit when a boiler replacement forces the decision anyway.

Quick comparison summary

Rough order of magnitude, assuming average insulation, 2026 prices, and BUS grant applied.

Oil/LPG: £800 to £1,500 year-one saving, payback 3 to 5 years
Old electric storage: £1,800 to £2,500 year-one saving, payback under 3 years
Modern gas, good insulation: plus or minus £100 year-one saving, payback not meaningful
Modern gas, poor insulation: minus £200 to minus £400 year-one saving, do not buy yet

The calculator on this site will compute your actual numbers in under two minutes, and will tell you if the answer is negative.

FAQ

How long does heat pump installation take?

For a standard 3-bed semi, one to two days on site once the installer is booked. Lead time from signing to installation is typically 4 to 10 weeks, longer at peak (September to December).

Can I use my existing radiators?

Usually yes, but the installer will size them. Heat pumps run at lower flow temperatures (around 45 to 55 degrees) than gas boilers (70 plus), so radiators need to be bigger to deliver the same heat. If your rads were installed in the last 10 years they are often already big enough, or need one or two swapped for a minor cost.

What is SCOP and why does it matter?

Seasonal Coefficient of Performance is how many units of heat the pump delivers per unit of electricity it uses, averaged across a heating season. A SCOP of 3.2 means 3.2 kWh of heat per 1 kWh of electricity. Higher is better. MCS fleet average is 3.2. Good installs hit 3.8 to 4.0. Bad installs drop to 2.5 and are the main reason people complain about running costs.

What if my EPC is low?

The BUS grant only requires that you do not have any outstanding loft or cavity wall insulation recommendations on your EPC. You do not need a specific EPC band. In practice, if your EPC says "insulate the loft" and you have not, either insulate (cheap) or fix the EPC recommendation.

What about hot water?

A heat pump heats hot water via a cylinder, typically in the airing cupboard. You lose combi-style instant hot water, gaining a buffered supply that reheats each afternoon or overnight. Most households find this a non-issue after a week. If you do not currently have space for a cylinder, flag this with the installer early.

Do I need a hot water cylinder?

Yes, for an air-source heat pump on a wet heating system. Modern cylinders are well insulated and lose very little heat. A 180 to 250 litre unit is typical for a family home.

Ready to see what the maths looks like for your home? Open the calculator and get postcode-level numbers, including whether a heat pump pays back for you or whether insulation should come first.