Process
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- Process
A simple, five-step journey
From first enquiry to lifetime aftercare clear, calm and completely hassle-free.
Enquiry
Get an instant online quote or call us we'll understand your needs in minutes.
Survey
A free, no-pressure survey (in person or by photo) to confirm the perfect solution.
Install / Repair
Gas Safe engineers complete the work cleanly and efficiently, often in a single day.
Testing
Full commissioning, safety checks and certification and we walk you through it all.
Aftercare
Warranty registration, servicing reminders and a team that's always a call away.
Your questions, answered
Everything you need to know about boilers, pricing and our service.
A new combi boiler installation in London typically ranges from £1,900 to £3,500, depending on the brand, boiler size and how complex the installation is. Use our instant quote tool above for a tailored, no-obligation price in under 90 seconds.
Yes — absolutely. Every Diamond Gas engineer is Gas Safe registered, fully insured and manufacturer-accredited by Baxi and Vaillant. We're happy to show our registration on arrival.
Yes. We offer same-day emergency callouts across London for boiler breakdowns, no heating, no hot water and suspected gas leaks. Call 07534 652448 and we'll prioritise you.
New installations come with up to a 10-year manufacturer warranty on Baxi and Vaillant units, plus our own workmanship guarantee. We register the warranty for you so you're covered from day one.
Most standard boiler swaps are completed within a single day. After your survey we can often install within 24–48 hours — sooner in an emergency.
Yes — we offer flexible finance options so you can spread the cost of a new boiler into affordable monthly payments. Ask our team for details when you request your quote.