BUS Grant Guide: Up to £9,000 for Heat Pumps in Wales (Oil/LPG, 21 Jul 2026–31 Mar 2027)
Complete guide to claiming the Boiler Upgrade Scheme grant. Step-by-step application process, eligibility requirements, and how to find approved installers in Wales.
The Boiler Upgrade Scheme (BUS) offers grants towards air source heat pump installations across England and Wales. There are two tiers: up to £9,000 if your home currently runs on oil or LPG (for voucher applications from 21 July 2026 to 31 March 2027), and £7,500 if you're on mains gas or electric. The aim is to accelerate the move away from fossil-fuel heating, and the larger oil/LPG figure reflects how much harder it is to switch off-grid homes.
This comprehensive guide covers everything Welsh homeowners need to know about claiming the grant, from eligibility checks to final installation approval.
What Is the BUS Grant?
The Boiler Upgrade Scheme is a government-funded programmerunning until March 2028. It provides upfront capital grants to reduce the cost of low-carbon heating system installations, making heat pumps more affordable for homeowners.
Grant Amounts & Eligible Technologies
Air Source Heat Pumps
- • Most popular choice
- • Suitable for most properties
- • Works with existing radiators
- • Lower installation complexity
Ground Source Heat Pumps
- • Higher efficiency potential
- • Requires garden space
- • More complex installation
- • Higher upfront costs
Biomass Boilers
- • Rural properties mainly
- • Fuel storage required
- • Ongoing fuel costs
- • Regular maintenance needed
Important: Grant Caps & Uplift Window
The grant cannot exceed the total installation cost. For example, if your heat pump installation costs £6,000, you'll receive £6,000 (not the full £9,000 or £7,500). Most quality installations cost £8,000–£15,000, so the full grant is usually available.
Oil/LPG £9,000 uplift: applies to voucher applications submitted from 21 July 2026 to 31 March 2027. Applications outside this window, or for mains gas/electric properties, receive £7,500.
Eligibility Requirements
BUS grant eligibility is straightforward but must be verified before installation. The scheme targets properties moving away from fossil fuel heating systems to achieve maximum carbon emissions reduction.
✅ Property Requirements
Location & Ownership
- • Located in England or Wales
- • Owner-occupied or privately rented
- • Single domestic property (not flats in shared blocks)
- • Must be your main residence
- • No existing government heating grants claimed
Existing Heating System
- • Oil boiler (any age or condition)
- • LPG boiler (any age or condition)
- • Mains gas boiler
- • Electric heating (including storage heaters)
- • Biomass or coal heating systems
- • No existing air or ground source heat pump
EPC and insulation conditions removed: As of current Ofgem rules, there is no minimum EPC rating requirement and no mandatory loft or cavity wall insulation condition to claim the BUS grant.
❌ What Makes You Ineligible
Existing Heating
- • Existing heat pump installations
- • Hybrid heating systems with heat pumps
- • Properties with communal heating
Property Type
- • New build properties (completed less than 12 months ago)
- • Flats in buildings with shared heating systems
- • Social housing properties
- • Commercial or mixed-use properties
The Application Process
The BUS grant application is handled entirely by your chosen installer — you don't apply directly. This streamlined process ensures technical compliance and reduces paperwork for homeowners.
Step-by-Step Process
Choose MCS-Certified Installer
Only installers with MCS (Microgeneration Certification Scheme) accreditation can apply for BUS grants. Verify their certification on the official MCS database.
- • Check MCS certificate validity
- • Confirm BUS scheme registration
- • Get multiple quotes for comparison
- • Verify insurance and warranties
Property Survey & System Design
Installer conducts detailed survey to design optimal heat pump system and verify grant eligibility.
- • Heat loss calculation and sizing
- • Radiator and hot water cylinder assessment
- • Electrical supply adequacy check
- • Planning permission requirements
- • BUS eligibility confirmation
Grant Voucher Application — Before Installation
Your installer submits the voucher application to Ofgem before any installation work begins. Installation cannot start until the voucher is approved.
- • Online application via Ofgem portal
- • Property details and heat pump specifications
- • Homeowner consent and declarations
- • No EPC or insulation documents required
- • Vouchers are usually issued within a few days to a few weeks (exact timing varies; Ofgem processes applications before installation may begin)
- • Once issued, the voucher is valid for 3 months for ASHPs and 6 months for GSHPs — installation must be completed and the voucher redeemed within this window
Installation & Commissioning
Once the voucher is approved, installation proceeds with full MCS compliance and certification.
- • Professional installation to MCS standards
- • System commissioning and performance testing
- • Homeowner handover and training
- • MCS certificate issuance
- • Warranty registration
Grant Deducted from Your Invoice
Ofgem pays the grant directly to the installer, who deducts it from your final invoice — you only pay the balance.
- • Automatic payment processing
- • Grant deducted from customer invoice
- • No upfront grant payment to homeowner
- • Clear invoice breakdown showing grant reduction
Finding Approved Installers in Wales
Only MCS-certified installers can apply for BUS grants. Choose carefully, as the installer handles your entire application and determines system design quality.
Installer Selection Criteria
Essential Qualifications
- MCS Certification: Valid heat pump installation certificate
- BUS Registration: Registered with Ofgem for grant applications
- Insurance: Public liability (£2M+) and product indemnity
- Local Presence: Established business with Welsh operations
- Experience: Proven track record of heat pump installations
Quality Indicators
- References: Recent local installations and customer feedback
- Aftercare: Comprehensive warranty and maintenance support
- Design Quality: Proper heat loss calculations and system sizing
- Communication: Clear explanation of grant process and timelines
- Transparency: Detailed quotes with all costs and exclusions
Finding Installers
- • MCS Database: Search certified installers by postcode on official MCS website
- • Manufacturer Networks: Vaillant, Midea, and Daikin approved installer programmes
- • Trade Associations: Heat Pump Association and RECC member directories
- • Local Recommendations: Word-of-mouth from successful installations
Costs & Financial Planning
The BUS grant significantly reduces heat pump costs. Oil/LPG homes can claim up to £9,000 (for applications from 21 July 2026 to 31 March 2027); mains gas/electric homes receive £7,500. Understanding total costs helps with financial planning.
Typical Installation Costs (After Grant)
Basic Installation
- • Standard 6-8kW heat pump
- • Existing radiators compatible
- • No electrical upgrades needed
- • Simple outdoor unit positioning
Standard Installation
- • 8-12kW heat pump system
- • Hot water cylinder upgrade
- • Some radiator replacements
- • Enhanced controls and monitoring
Premium Installation
- • High-efficiency heat pump
- • Underfloor heating zones
- • Consumer unit upgrade
- • Advanced weather compensation
Additional Costs to Consider
Potential Extras
- • Planning permission applications (£200-£500)
- • Electrical consumer unit upgrade (£800-£1,500)
- • Larger radiators for optimal efficiency (£200-£500 each)
- • Improved insulation if required (£500-£2,000)
- • Structural work for cylinder positioning (£300-£800)
Finance Options
- • Cash payment: Best total cost, immediate ownership
- • Personal loans: 3-7% APR, flexible terms
- • Heat pump loans: Specialist products, competitive rates
- • Remortgaging: Lowest rates, longer terms available
- • Installer finance: Convenient but check rates carefully
Timeline & What to Expect
The complete BUS grant and installation process typically takes 4-6 weeks from initial contact to system commissioning. For emergency situations with broken boilers, we can offer rush service with turnaround in as little as 2 weeks.
Typical Project Timeline
Weeks 1-2: Initial Assessment & Quote
1-2 weeks- • Property survey and heat loss calculations
- • System design and specification
- • Detailed quotation provided
- • Contract agreement and deposit
Weeks 2-3: Application & Planning
1 week- • BUS voucher application submitted to Ofgem (must be approved before installation)
- • Planning permission (if required)
- • Equipment ordering and delivery scheduling
- • DNO notification for electrical work
Ofgem Processing: Grant Voucher Issued
a few days to a few weeks- • Ofgem reviews the application — timing varies; usually a few days to a few weeks
- • Grant voucher issued; valid for 3 months (ASHP) or 6 months (GSHP) from issue date
- • Installation must be completed and voucher redeemed within this validity window
- • Installation date scheduling and final material delivery
Week 4 Onwards: Installation
1-2 weeks- • Heat pump and system installation (2-5 days)
- • System commissioning and testing
- • MCS certification completion
- • Homeowner training and handover
🚨 Emergency Rush Service Available
For broken boilers and heating emergencies, we can offer rush service with complete installation turnaround in as little as 2 weeks. Simply sign our express work consent form to expedite the process.
Ready to Apply for Your BUS Grant?
The BUS grant makes heat pumps affordable for most Welsh homeowners, typically reducing installation costs by 40-60%. With professional installation and government support, now is an excellent time to make the switch.
Next Steps
- • Verify your eligibility (most properties now eligible)
- • Contact Renewable Future Wales or other MCS & Trustmark certified installers
- • Compare total costs after grant deduction
- • Check installer credentials and references
- • Confirm grant application process and timeline
Questions to Ask
- • "Can you confirm my BUS grant eligibility?"
- • "What's the total cost after the BUS grant — and do I get the higher £9,000 oil/LPG rate?"
- • "How long will the application take?"
- • "What warranties and aftercare do you provide?"
- • "Can you provide local customer references?"