How to Vet an MCS Heat Pump Installer UK 2026

MCS (Microgeneration Certification Scheme) certification is a non-negotiable requirement for the £7,500 Boiler Upgrade Scheme grant. Without it, the grant is rejected + you've lost the most valuable financial lever in the install.

How to verify:

1. Go to the MCS Certified register.
2. Search the installer's company name (not the salesperson's name).
3. Confirm the certificate scope includes 'Heat Pumps - Air Source' (or Ground Source if applicable).
4. Note the certificate expiry date - if it expires within 6 months, ask whether the installer's renewal is in progress.

Common gotcha: large nationals (BOXT, Octopus Energy, Aira) hold MCS certification at the company level. Smaller installers may hold it at the individual or company level - both are valid; check both.

Under UK F-Gas regulations, anyone handling refrigerant-containing equipment must be F-Gas certified at the individual level. This applies to:

• The engineer who commissions the heat pump.
• Any engineer who returns for annual service or repair.

MCS certification at the company level doesn't automatically mean every engineer holds F-Gas - ask for the specific engineer's F-Gas certification number when scheduling install. Reputable installers will provide it without hesitation. Refusal is a red flag.

A reputable installer should be able to show you 5+ real case studies from their recent UK installs. Quality of case studies separates serious installers from form-letter operations:

• Address/postcode (or anonymised area): proves the install is real + in your region's climate band.
• Install date: within last 12-18 months ideally (vs ancient 2018 examples).
• Heat pump model + size: matches the type they'd quote for your property.
• Actual SCOP reading: bonus marks - real operational data not just lab-spec figures.
• Customer testimonial: with name (anonymised first name is fine).

If an installer offers only marketing material without specific case studies, they're not running enough volume to have real examples. Walk away.

Cross-reference the installer's reputation across at least 2 independent review platforms:

• Trustpilot: typically the largest review surface for UK heat pump installers. Minimum 50 reviews + 4.5 average score.
• Checkatrade: trades-focused with stronger anti-fake-review controls. Minimum 20 reviews + 9.0/10 average.
• Google Business Profile: location-specific reviews + photos.
• Which? Trusted Trader: for installers who've passed the Which? vetting process.

Filter for recent reviews specifically. An installer with 500 reviews from 2019-2022 + 10 from 2025-2026 may have changed ownership, lost key engineers, or expanded too fast - all of which can mean the recent experience is much worse than the historical average.

Heat pump installation involves electrical work, refrigerant handling, hydronic system modification - any of which can cause significant property damage if done badly. Insurance covers you when something goes wrong:

• Public liability insurance: covers third-party injury or property damage during the install. Minimum GBP 2 million; GBP 5 million is better.
• Professional indemnity insurance: covers design errors (e.g. unit sized wrong, location chosen unsafely). Minimum GBP 2 million.
• MCS-required warranty insurance: covers your heat pump for the manufacturer warranty period if the installer goes out of business. Required for BUS grant compliance.

Reputable installers will provide certificates on request. Refusal is grounds to walk away.

A transparent quote should clearly itemise:

• Heat pump unit cost (manufacturer + model + capacity + RRP comparable to the manufacturer's published list price).
• Indoor unit + hot water cylinder cost (if separate from main heat pump).
• Pipework + radiator changes (specific items, not lumped 'pipework adjustments').
• Electrical work + DNO consent (G98/G99 application costs).
• BUS grant deduction (£7,500 explicitly shown as negative line item).
• Commissioning + first-year service (often bundled into install but should be itemised).
• Warranty terms (years + scope).

Vague quotes ('Heat pump install GBP 11,000') are an immediate red flag - they're either hiding scope changes or planning to upsell during install. Get 3 itemised quotes from 3 installers + compare line-by-line.

1. Refuses to provide MCS certificate number for register verification. Non-negotiable - the BUS grant requires MCS-certified install.
2. Won't quote without a 'site survey deposit' over GBP 100. Reputable installers offer free quotes (occasionally GBP 50 for very remote travel). A high upfront fee suggests difficulty getting customers via normal channels.
3. Pressures you to sign within 7 days for a 'discount'. Decision-pressure tactics indicate sales-driven rather than technical-driven operation. Real engineering work doesn't have time-limited discounts.
4. Quote significantly higher OR lower than the other 2. ~15-25% above the median quote suggests price-skimming a less-informed customer; ~15-25% below suggests corner-cutting on materials, install time, or commissioning quality.
5. Refuses to leave the old gas boiler operational as backup. Reputable installers leave the gas system pluggable as backup for the first winter while the heat pump beds in. Forcing immediate decommissioning indicates lack of confidence in their own work.