New boiler installation by Gas Safe registered engineers
Boiler Installation
Boiler installation covers fitting a new gas combi, system or regular boiler, correctly sized for the property, along with associated pipework and controls, carried out by Gas Safe registered engineers.
Definition
What boiler installation involves
Installing a new boiler involves more than a like-for-like swap decision: correctly sizing the appliance for the property's heat and hot water demand, deciding on combi, system or regular boiler type, and specifying appropriate controls. New installations must also meet current Building Regulations Part L energy efficiency requirements.
Suitable for
- New heating installations as part of an extension or new build
- Upgrading from an old or undersized boiler
- Changing boiler type (e.g. regular to combi) as part of a wider renovation
Not suitable for
- Anyone other than a Gas Safe registered engineer carrying out the installation — this is a legal requirement
Process
How the work is carried out
- 01
Assessment
Assessing property heat loss and hot water demand to size the new boiler correctly.
- 02
Specification
Agreeing boiler type, output, brand and controls.
- 03
Installation
Installing the boiler, associated pipework and controls to current standards.
- 04
Commissioning
Commissioning and testing the complete system.
- 05
Certification
Issuing a Gas Safe certificate and Building Regulations notification via the Competent Person Scheme.
Typical timescale
A straightforward like-for-like installation typically takes one to two days; a boiler type change or relocated boiler takes longer.
Cost guidance
Cost depends on boiler output, brand and any pipework or flue changes needed. An itemised quotation follows a site assessment.
Limitations and exclusions
- Installation is carried out only by Gas Safe registered engineers, in line with legal requirements
- Radiator and pipework upgrades beyond the boiler itself are scoped separately unless included at outset
Areas we cover
Boiler Installation across Sussex, Surrey, Kent and South London
Local property styles, planning authorities and neighbourhood coverage for boiler installation in each town we work in.
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FAQs
Boiler Installation FAQs
How do I know what size boiler I need?
Boiler output should match your property's heat loss and hot water demand — an oversized or undersized boiler runs less efficiently. We calculate this properly during assessment rather than defaulting to a like-for-like replacement.
Discuss your boiler installation project
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-19.