How much does a new boiler cost?

Questions about boiler replacement costs

How much does it cost to replace a boiler in London?

A like-for-like combi boiler replacement in London typically costs £1,500 to £3,000 for supply and fit, depending on the brand tier. Budget brands such as Ideal and Baxi sit at the lower end, while mid-range brands like Worcester Bosch and Vaillant fall in the middle. Premium options such as Viessmann can reach £4,500 or more. Prices in London are generally higher than the national average due to labour costs.

What affects the cost of a new boiler installation?

The main factors are property size (which determines the boiler output needed), the brand and model chosen, whether you are replacing like-for-like or switching boiler type, and any additional work required such as new pipework, a replacement cylinder, or moving the boiler to a new location. Switching from a regular or system boiler to a combi, for example, typically adds £500 to £1,200 because the old cylinder must be removed and pipework reconfigured.

Is a budget boiler worth buying, or should I spend more?

Budget boilers from brands like Ideal and Baxi are reliable and carry manufacturer warranties, making them a sound choice if upfront cost is a priority. Mid-range brands such as Worcester Bosch and Vaillant offer a longer track record for longevity and slightly better efficiency ratings. Premium brands like Viessmann are often chosen for their build quality and extended warranties. For most London homes, a mid-range combi is the most cost-effective long-term choice.

How long does a boiler installation take?

A straightforward like-for-like combi boiler swap typically takes one day. More complex installations - such as switching boiler type, moving the boiler location, or replacing a hot water cylinder - may take one to two days. Renzy engineers aim to complete all standard replacements within a single visit.

Does the estimate include parts and labour?

Yes. The estimate produced by this calculator covers supply and fit - meaning the boiler unit itself plus installation labour. It does not include optional add-ons such as a magnetic system filter or a new thermostat unless you selected those in the calculator. Renzy provides fully itemised fixed quotes so you know exactly what you are paying before any work begins.