Boiler Installation London — Gas Safe Registered Engineers

A new combi boiler fully installed — including all pipework modifications, flue, controls and commissioning — typically costs £2,200–£3,500 for a standard back-boiler replacement or like-for-like swap. Converting from a conventional to a combi boiler (removing the hot water cylinder and cold tank) is £2,800–£4,500 depending on the amount of pipework involved. Worcester Bosch and Vaillant are the most reliable long-term choices; both come with 10-year manufacturer warranties when installed by an accredited installer.

A like-for-like combi boiler replacement typically takes 6–8 hours — one working day. A full conversion from conventional to combi (removing a hot water cylinder and cold water tank in the loft) takes 1–2 days depending on the amount of pipework rerouting required. We give you a fixed time estimate when we quote.

Worcester Bosch and Vaillant are the most reliable makes in our experience — both have good parts availability and offer 10-year warranties on their premium ranges when installed by accredited engineers. Ideal is a solid mid-range option. Baxi is also reliable and competitively priced. We'll recommend the most suitable model for your property's hot water demand and heating system — a combi isn't right for every house.

Yes. Old boiler removal and disposal is included in our installation price. We disconnect the old appliance safely, cap off any redundant pipework, and take the unit away. If you're having a hot water cylinder and cold tank removed as part of a combi conversion, that's included too.

We commission and fully test the boiler on installation day and register the manufacturer warranty in your name. We recommend an annual service from year 2 onwards — these are typically £85–£120 and take around 45 minutes. Annual servicing is a condition of most manufacturer warranties.