QUESTIONS
How long does it take to fit a new boiler?
Updated 08/26
By: Tommy Burgess
Reviewed: Kim Staples
There's no single answer, since installation time can range from a few hours to several days, depending largely on whether you're doing a straight swap or something more involved.
What actually drives installation time
Realistic timescales for different scenarios
Why moving or changing boiler type adds days, not hours
What to ask your installer before booking
Where to get an accurate quote
Find boiler fitters near you
How long does it take to fit a new boiler?
Installation time varies considerably, from as little as 4-6 hours to 3-4 days, depending on your specific situation.
What affects installation time?
Whether you're replacing an existing boiler or installing one for the first time
Whether the new boiler goes in the same location or is being relocated
The fuel type, and whether it's changing from your current supply
The boiler type, and whether it's changing from your existing one
Access to the property and boiler location
Average timings for fitting a new boiler
As a general guide:
Straight boiler swap (like-for-like, same location): 4-6 hours
Changing the boiler's location: 1-2 days
Installing a completely new combi boiler: 1-2 days
Changing the type of boiler: 2-3 days
Changing the fuel type: 2-3 days
Changing both the type and location: 3-4 days
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Why does changing type or location add so much time?
A like-for-like swap simply disconnects the old unit and connects the new one to existing pipework and flue.
Changing type (say, regular to combi) or relocating the boiler means removing or adding a hot water cylinder, rerouting pipework, and often repositioning the flue, all of which add genuine labour time on top of the installation itself.
How much does a new boiler cost in the UK in 2026?
Our comprehensive guide outlines the average cost of a new boiler, running costs, and potential additional expenses to budget for.
Getting an accurate estimate
Whatever your boiler situation, speak to local boiler fitters directly for professional advice specific to your home.
A installer can give guidance on both timing and cost once they've seen your setup, rather than relying on general averages alone.
Before you book an installation
Find a local tradesperson
Find boiler fitters near you
FAQs
Typically 4-6 hours, since it's usually a straightforward disconnection and reconnection using existing pipework and flue.
Around 2-3 days, since this usually involves removing or adding a hot water cylinder and reworking pipework.
Yes, typically 1-2 days on top of a standard installation, since new pipework and often a repositioned flue are needed.
Not reliably; access, existing pipework condition, and property layout all affect the final time, so a specific quote from a local installer is the most accurate route.
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