Heat Pumps in the UK: Costs, Savings & the BUS Grant (2026)

Heat pumps are 3-4x more efficient than gas boilers, but cost £8,000-£15,000 to install (after £7,500 BUS grant). They work best in well-insulated homes with underfloor heating or oversized radiators. Here's an honest assessment of whether a heat pump is right for you.

What is a Heat Pump?

A heat pump extracts heat from the outside air (ASHP) or ground (GSHP) and transfers it into your home. Think of it as a refrigerator in reverse—it moves heat rather than creating it.

Key advantage: For every 1 kWh of electricity used, a heat pump delivers 3-4 kWh of heat. Gas boilers only deliver 0.85-0.92 kWh per kWh of gas.

Types of Heat Pumps

SCOP Explained

SCOP (Seasonal Coefficient of Performance) measures heat pump efficiency over a full heating season. It's the ratio of heat output to electricity input.

• SCOP 3.0: For every 1 kWh of electricity, you get 3 kWh of heat
• SCOP 3.5: For every 1 kWh of electricity, you get 3.5 kWh of heat
• SCOP 4.0+: For every 1 kWh of electricity, you get 4+ kWh of heat

Compare this to gas boilers (efficiency 85-92%) which produce less than 1 kWh of heat per kWh of gas. Heat pumps are fundamentally more efficient.

Realistic Costs (2026)

Air Source Heat Pump (ASHP)

Ground Source Heat Pump (GSHP)

The Boiler Upgrade Scheme (BUS)

The UK government's Boiler Upgrade Scheme (BUS) provides grants for low-carbon heating systems:

• Air source heat pumps: £7,500 grant
• Ground source heat pumps: £7,500 grant
• Biomass boilers: £5,000 grant (less common)

BUS Eligibility Requirements

• Property must be in England or Wales (Scotland has separate schemes)
• Must replace fossil fuel heating (gas, oil, LPG, electric)
• Installer must be MCS certified
• EPC must be valid (less than 10 years old)
• No outstanding EPC recommendations for loft or cavity wall insulation
• Heat pump must meet minimum SCOP requirements (2.8 for ASHP, 2.5 for GSHP)

The BUS scheme is currently funded until 2028, but budgets are limited. Apply early to secure funding. Last reviewed 18 June 2026.

Real-World Savings: The Honest Take

Heat pump running costs depend heavily on your current heating system, insulation, and electricity tariff:

Replacing Oil or LPG Heating

Expected savings: £500-£1,200/year
Oil and LPG are expensive (12-15p/kWh equivalent). Even with higher electricity prices, heat pumps typically save money.

Replacing Old Electric Storage Heaters

Expected savings: £600-£1,000/year
Direct electric heating is expensive. Heat pumps are 3x more efficient, delivering substantial savings.

Replacing Modern Gas Boiler

Expected savings: £0-£200/year (possibly higher costs)
This is where heat pumps struggle financially. Gas is cheap (7p/kWh), and even with 3x efficiency, electricity at 27p/kWh means similar or slightly higher costs.

Based on typical 3-bed semi-detached home with 12,000 kWh annual heat demand. Electricity at 27p/kWh, gas at 7p/kWh, oil at 12p/kWh equivalent (2026 prices).

When Heat Pumps Make Sense

Heat pumps are a good investment when:

• Replacing oil, LPG, or electric heating: Clear financial savings
• Off-gas grid: No mains gas connection available
• Well-insulated home: EPC Band C or better
• Underfloor heating or oversized radiators: Works with lower flow temperatures
• New build or major renovation: Cost-effective to design for heat pumps
• Solar panels installed: Reduces electricity costs significantly
• Environmental priority: Willing to pay slightly more for lower carbon
• Long-term planning: Gas prices may rise, electricity may fall

When Heat Pumps Don't Make Sense

Heat pumps may not be suitable if:

• Modern gas boiler + poor insulation: Fix insulation first
• Small radiators: Expensive upgrades required (£1,000-£2,500)
• Listed building: Planning restrictions on external units
• No outdoor space: Nowhere to install external unit (ASHP)
• Tight budget: Even with BUS grant, upfront costs remain significant
• Short-term occupancy: Payback period may exceed time in property

Heat Pump Installation Requirements

Insulation

Heat pumps work best with good insulation (EPC Band C or better). Before installing a heat pump, ensure you have:

• Loft insulation (270mm minimum)
• Cavity wall insulation (if applicable)
• Double glazing
• Draught proofing

Radiators and Flow Temperature

Heat pumps operate at lower flow temperatures (45–55°C) than many gas boilers (60–80°C). You may need to upgrade radiators to larger models or add additional radiators. The same principle applies to condensing boilers: running radiators cooler where comfort allows improves efficiency—a step Nesta emphasised during Guy Martin's House Without Bills retrofit alongside the heat pump install. See Nesta's project notes for how commissioning tied fabric, flow temperature, and monitoring together. If you are still on gas, try lowering boiler flow temperature before sizing a heat pump.

Hot Water Cylinder

Most heat pumps require a hot water cylinder (200-300L). If you currently have a combi boiler, this is an additional cost and space requirement.

Electrical Supply

Heat pumps draw 3-5 kW. Your electrical system must support this load. Some homes require consumer unit upgrades (£500-£1,000).

Finding MCS-Certified Installers

MCS (Microgeneration Certification Scheme) accreditation is mandatory for BUS grant eligibility. To find installers:

1. MCS Certified Installer Database: mcscertified.com
2. Get 3+ quotes: Compare costs, equipment, and warranties
3. Check reviews: Look for Trustpilot, Google reviews, case studies
4. Ask about SCOP: Ensure quoted system meets minimum standards
5. Warranty coverage: Minimum 5 years on heat pump, 2 years on installation

Heat Pump Performance in Cold Weather

Common myth: "Heat pumps don't work in cold UK winters."
Reality: Modern heat pumps operate efficiently down to -15°C to -25°C. UK winter temperatures rarely drop below -5°C, so performance is not a concern.

However, efficiency does decrease in colder weather. A heat pump with SCOP 3.5 may achieve SCOP 4.0+ in mild weather but drop to SCOP 2.5-3.0 in freezing conditions.

Carbon Savings

Heat pumps reduce carbon emissions compared to fossil fuel heating:

• vs Gas boiler: 30-50% CO2 reduction (UK grid mix)
• vs Oil boiler: 50-70% CO2 reduction
• vs LPG boiler: 50-70% CO2 reduction
• With solar panels: 80-90% CO2 reduction

As the UK grid decarbonizes (more renewables, less gas), heat pump carbon benefits will increase over time.

Payback Period Calculation

Heat Pumps, EPC Ratings, and Real Bills

Installing a heat pump often moves the needle on your EPC rating—sometimes by two bands when replacing an old boiler and pairing with insulation—because SAP rewards efficient heat delivery and lower carbon intensity. That SAP uplift does not automatically mean lower monthly direct debits if you switch from a modern gas boiler at 2026 electricity prices.

BUS eligibility also references your certificate: you need a valid EPC, and outstanding recommendations for loft or cavity insulation may need addressing first. Treat the EPC as the regulatory and modelling view; treat meter readings as the financial truth. Many households improve both by sequencing fabric, then heating, then tariffs—not by skipping straight to hardware.

Future-Proofing Your Home

Even if heat pumps don't save money today vs gas boilers, future changes may shift the economics:

• Rising gas prices: Gas levy expected to fund grid upgrades
• Falling electricity costs: Renewable energy becoming cheaper
• Carbon pricing: Fossil fuels may become more expensive
• Hydrogen uncertainty: Hydrogen boilers still unproven at scale
• Building regulations: Future homes standard may mandate heat pumps

Frequently Asked Questions

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

Most compelling when replacing oil, LPG, or direct electric heating in a reasonably insulated home. Gas replacements are often a carbon and EPC play unless you have solar or cheaper electricity.

How much does a heat pump cost after BUS?

Many air-source installs net around £500–£4,500 after the £7,500 grant, but radiator, cylinder, and electrical work can push totals higher. Always compare three MCS quotes.

What flow temperature should a heat pump use?

Typically 45–55°C for space heating. Lower is better for SCOP if radiators and fabric support it—the same logic as tuning gas boiler flow down before a full system swap.

Do heat pumps work in UK winters?

Yes, with correct sizing and commissioning. Efficiency dips in cold snaps but remains usable across typical UK temperatures.

Next Steps

1. Check insulation: Ensure EPC Band C or better before considering heat pumps
2. Get heat loss survey: Determine required heat pump size
3. Request MCS quotes: Compare 3+ certified installers
4. Apply for BUS grant: Installer typically handles application
5. Plan radiator upgrades: Budget for larger radiators if needed
6. Consider solar: Maximizes heat pump cost-effectiveness