Boiler guide · 4 min read · Updated October 2026
Boiler installation cost: what the labour actually covers
The difference between the boiler price and the installed price, what a proper installation includes, and what a combi installation costs.
Hardware vs installed price
The boiler itself is typically half to two-thirds of an installed price. The rest is the work that makes it safe, legal and efficient — and it is where cheap quotes cut corners.
What a proper installation includes
- Removing and disposing of the old boiler
- Flue installation or replacement
- System flush and magnetic filter fitting
- Gas, water and condensate pipework connections
- Commissioning with combustion analysis
- Benchmark registration and manufacturer warranty registration
- Controls setup and a walkthrough so you can actually run it
Combi installation costs
A like-for-like combi installation from our catalogue starts at £2,415 including VAT, all-in. Larger outputs and conversions cost more — the quote builder prices your exact job and the figure is fixed after survey.
Red flags in a cheap quote
- No mention of a system flush or filter
- No commissioning or Benchmark registration
- Warranty registration left to you — some extended terms must be registered by the installer
- A price given without anyone asking about your flue, pipework or gas supply
Common questions
Why is installation such a large part of the cost?
Because the labour, flue, flush, filter, commissioning and warranty registration are what make the boiler safe and keep its warranty valid. The boiler box itself is only part of the job.
Can I supply my own boiler for you to fit?
Our fitted prices are for boilers we supply, so the warranty registration and pack contents are under our control. If you want to use your own installer, our shop sells supply-only packs instead.
Ready for a real price?
Build a fitted boiler quote in about two minutes, or browse over 700 supply-only boiler packs in the shop.