Interactive calculator with real prices adjusted by UK region. Select your scope, pick your region, get your instant estimate.
1. Choose Scope of Work
2. Select Your Region
What Affects the Cost?
Boiler brand and model
Existing pipework condition
Flue routing complexity
Controls and thermostat upgrade
Removal of old boiler
Power flush of system
Frequently Asked Questions
How much does a new combi boiler cost installed UK?
A new combi boiler installed typically costs £1,800-£3,000 for a like-for-like replacement. If the boiler needs relocating, expect £2,500-£4,000. Prices include the boiler, installation, and commissioning.
Is it worth replacing a 15 year old boiler?
Yes. Modern boilers are 90-94% efficient vs 70-80% for older models. The energy savings of £200-£400/year mean a new boiler often pays for itself in 5-8 years, plus you get a new warranty.
What is the best combi boiler UK?
Worcester Bosch, Viessmann, and Vaillant consistently rank highest for reliability. Worcester Bosch offers the longest standard warranty (up to 12 years). The best choice depends on your home size and hot water demand.