Complete Guide to Boiler Installation

Getting a new boiler installed can feel overwhelming if you've never been through it before. This guide walks you through the entire process so you know exactly what to expect.

Step 1: Survey and quote

A reputable installer will visit your property to assess your current system, heating requirements, and ideal boiler location. This is where they'll identify any additional work needed (such as upgrading pipework or adding a magnetic filter). This visit should be free.

Step 2: Choosing your boiler

Based on the survey, your installer will recommend appropriate boiler models. Consider: type (combi, system, heat-only), brand reputation, warranty length, and budget. Don't let anyone pressure you into the most expensive option without a clear explanation of the benefits.

Step 3: Installation day

Most combi boiler replacements take 1–2 days. A like-for-like combi swap is often completed in a single day. System conversions and full system replacements take longer. Expect: removal and disposal of old boiler, installation and fluing of new boiler, power flush of the system if needed, fitting controls, and commissioning and testing.

Step 4: Commissioning and handover

A properly commissioned boiler is started up, tested at full load, and all safety devices verified. You should receive: Gas Safe certificate, manufacturer's warranty registration, and a full handover explaining the controls.

Step 5: Ongoing maintenance

Annual service required to maintain warranty and efficiency. Book your first service before the anniversary of installation.