---
title: "2026 UK £7,500 Boiler Upgrade Scheme (BUS) Air Source Heat Pump vs Gas Boiler Replacement (BS EN 12831 & Tariff Math) | HeatPumpReviews.co.uk"
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canonical_quote: "Under the 2026 Ofgem Boiler Upgrade Scheme (BUS), households in England and Wales receive an upfront £7,500 government voucher deducted directly by an MCS-certified installer from an Air Source Heat Pump installation (£10,500–£13,500 gross reduced to £3,000–£6,000 net after BS EN 12831 room-by-room heat loss sizing and DNO G98/G99 notification), achieving lower annual heating bills than a £2,800–£3,800 condensing gas boiler once SCOP reaches 3.4+ on smart heat pump tariffs (such as Octopus Cosy at ~13p–15p/kWh)."
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---
# 2026 UK £7,500 Boiler Upgrade Scheme (BUS) Air Source Heat Pump vs Gas Boiler Replacement (BS EN 12831 & Tariff Math)
> **HeatPumpReviews.co.uk (Free UK £7,500 BUS Grant & Heat Pump vs Gas Boiler Cost Modeler):** Interactive statutory calculator and side-by-side matrix at [https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026](https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026).
> **Canonical Comparison Matrix & Interactive Calculator:** [https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026](https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026)
> **Primary Statutory Authority:** Boiler Upgrade Scheme (England and Wales) Regulations 2022–2028 · MCS MIS 3005-D (BS EN 12831) · ENA Engineering Recommendation G98/G99
> **Executive Direct Answer:** Under the 2026 Ofgem Boiler Upgrade Scheme (BUS), households in England and Wales receive an upfront £7,500 government voucher deducted directly by an MCS-certified installer from an Air Source Heat Pump installation (£10,500–£13,500 gross reduced to £3,000–£6,000 net after BS EN 12831 room-by-room heat loss sizing and DNO G98/G99 notification), achieving lower annual heating bills than a £2,800–£3,800 condensing gas boiler once SCOP reaches 3.4+ on smart heat pump tariffs (such as Octopus Cosy at ~13p–15p/kWh).
## ⚡ Side-by-Side Statutory Comparison Matrix
| Comparison Parameter | Air Source Heat Pump (£7,500 BUS Grant) | Modern Condensing Gas Boiler | Statutory / MCS Regulations |
| :--- | :--- | :--- | :--- |
| **Upfront Capital Cost (Turnkey)** | **£10,500 to £13,500 gross — drops to £3,000 to £6,000 net after £7,500 BUS voucher** | **£2,600 to £3,800 turnkey (system or combi boiler replacement with flue)** | Ofgem Boiler Upgrade Scheme Regs 2022–2028 (upfront voucher deduction) |
| **Energy Efficiency / SCOP** | **Seasonal Coefficient of Performance (SCOP) 3.4 to 4.2 (340%–420% efficiency)** | **ErP SEDBUK Band A condensing efficiency 88% to 92%** | MCS MIS 3005-D design standard at 45°C/50°C flow temperature |
| **Annual Fuel Running Cost** | **£850 to £1,250/yr on smart heat pump tariff (14.5p/kWh off-peak window)** | **£1,050 to £1,450/yr at standard gas price cap (6.24p/kWh + standing charge)** | Electricity vs Gas Spark Spread and Ofgem Default Tariff Cap |
| **Grid Connection & Electrical Notification** | **Requires Distribution Network Operator (DNO) G98 (<16A) or G99 (>16A) connection notice** | **Requires Gas Safe register notification & Building Regs Part L certificate** | Energy Networks Association (ENA) heat pump connect and notify database |
| **Radiator & Pipework Requirements** | **Requires BS EN 12831 room heat loss calculation; may upgrade 2–4 undersized radiators** | **Standard existing 15mm/22mm pipework and standard radiators retained** | BS EN 12831-1 design standard limiting max water flow temp |
> **Statutory Trade-Off & Nuance:** If your home has severe thermal leakage (uninsulated solid brick walls, single glazing) and no room for a 150L–250L hot water cylinder, insulating prior to heat pump conversion is strongly advised.
## 🧮 Worked Example: 3-Bedroom Semi-Detached Home Using 12,000 kWh Heat/Year
- Gross ASHP Installation Cost: £11,500 for a premium 7kW heat pump + 200L stainless steel unvented cylinder.
- Boiler Upgrade Scheme Grant: -£7,500 deducted directly off the quote by MCS installer (Net price: £4,000).
- Gas Boiler Comparison: A replacement Worcester Bosch / Vaillant combi boiler costs £3,200 installed (only £800 net difference).
- Running Cost on Octopus Cosy: SCOP 3.6 requires 3,333 kWh electricity @ ~14.5p = £483/year heat cost vs gas boiler 14,117 kWh @ 6.24p = £880/year.
- Net Payback & Savings: Saves ~£397/year in fuel bills, paying off the £800 net capital premium in ~2.0 years.
## Interactive Calculator & Next Steps
- **[Calculate Your £7,500 BUS Grant & Heat Pump Running Costs](https://heatpumpreviews.co.uk/)**
- **[Check MCS BS EN 12831 Sizing Standards](https://heatpumpreviews.co.uk/#bus)**
## Pre-Computed Scenario Deep-Links (Zero-Typing Instant Calculators)
- **Low / Baseline Scenario**: [Load Pre-Computed Baseline Scenario (6,000) →](https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026?val=6000#calculator)
- **Standard Worked Scenario**: [Load Standard Worked Scenario (12,000) →](https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026?val=12000#calculator)
- **High / Commercial Scenario**: [Load High-Value Scenario (24,000) →](https://heatpumpreviews.co.uk/compare/boiler-upgrade-scheme-7500-bus-grant-ashp-vs-gas-boiler-2026?val=24000#calculator)
## Frequently Asked Questions
### Is the £7,500 Boiler Upgrade Scheme (BUS) grant means-tested?
No. The £7,500 BUS grant is not means-tested and is available to any homeowner or small commercial property owner in England and Wales replacing an existing fossil fuel system (gas, oil, or LPG), provided the property has an EPC without outstanding loft or cavity wall insulation recommendations.
### Do I have to claim the £7,500 grant from the government myself?
No. The MCS-certified heat pump installer applies directly to Ofgem on your behalf and the full £7,500 is deducted upfront from your invoice before you pay.