Choosing a boiler installer is one of the most important decisions you'll make for your home. Here's what to look for — and what to avoid.
Essential checks
Gas Safe registration: Non-negotiable. Ask for the engineer's Gas Safe card and verify it at GasSafeRegister.co.uk. A Gas Safe engineer's work is legally compliant and safe.
Fixed, written price: Any reputable company should be willing to give you a fully itemised, fixed price in writing before work begins. Walk away from anyone who gives a vague estimate and adds extras afterwards.
Local reviews: Check Google Reviews, Checkatrade, or Which? Trusted Traders for recent customer feedback. Look for consistent themes — punctuality, cleanliness, communication, and quality of work.
Red flags to watch for
- Cash-only payment requests
- Reluctance to show Gas Safe ID
- No written quote or itemised price
- Extreme urgency to sign today
- Very low prices that seem too good to be true
The accreditation advantage
Brand accreditations (Worcester Bosch Accredited, Vaillant Advance Installer) are only awarded to installers who meet the manufacturer's quality and training standards. Accredited installers can offer extended warranties that other engineers can't — often 10–12 years vs 5 years standard.