New Boiler Installation in London

Gas Safe registered engineersFixed prices agreed before workOFTEC & MCS certified where requiredRepairs, servicing & installations

Boiler prices are opaque mostly because quotes hide the split between appliance, labour and system extras. Ours don't: you'll see the boiler, the flue, the filter, the controls, the chemical flush and the labour itemised — and the guide table below sets expectations before the survey.

Gas Safe registered: Boiler Installation & Replacement in London is carried out by Gas Safe registered engineers — the legal requirement for work on gas appliances in the UK. You can verify any engineer’s ID card against the Gas Safe Register before work begins, and our network checks registration before a job is assigned.

London heating notes: London's supply is hard — Thames Water draws heavily from chalk aquifers and the Thames itself, so limescale builds fast on heating elements, shower heads and tap internals. London's stock runs from Victorian and Georgian terraces with generations of altered pipework to high-rise flats with pumped and boosted supplies, and each brings its own failure patterns. Mains supply here is managed by Thames Water.

Combi, system or heat-only — the honest steer

Combi boilers heat water on demand — no cylinder, no tank, ideal for homes with one bathroom and decent mains flow. System boilers feed an unvented cylinder: better for two-plus bathrooms running simultaneously, at the cost of cylinder space. Heat-only (conventional) boilers with tanks suit some older systems where wholesale conversion isn't worth it. The deciding facts are your bathroom count, mains flow rate and airing-cupboard real estate — not fashion.

What happens on installation day

Day one, the outgoing boiler comes off and the new one goes up: flue, condensate, gas and water connections made, the system flushed and dosed, filter and controls fitted. Commissioning is the part that separates professionals — combustion analysed, gas rate verified, the benchmark log completed and building control notified. You end the day with a working system, a registered warranty and paperwork that will matter when you sell the house.

Warranties, paperwork and aftercare

The boxes that must be ticked: warranty registered with the manufacturer within the deadline, building-control notification lodged (the Gas Safe notification handles this for gas installs), benchmark commissioning record completed in the boiler's log, and your first annual service booked eleven-ish months out to keep the warranty alive. Network installers do all four as standard — it's a condition of taking installation work through us.

Pricing for boiler installation & replacement in London tracks the national bands closely, with the usual local caveats: access difficulty in older Ealing properties, parts availability for the boiler families common here, and the seasonal demand curve that makes autumn bookings cheaper and calmer than January ones. You will always see the price structure before an engineer travels.

Frequently asked questions

How much is a new boiler in London?

Most London combi replacements land between £1,800 and £2,800 installed; conversions and system-boiler installs range higher, typically £2,500–£4,500. Your fixed quote follows a survey — the quote form on this page captures what the surveyor needs to price accurately.

How long does a boiler installation take?

A like-for-like combi swap: usually one day. A conversion from cylinder system to combi, or a relocation: two to three days. You'll be told the expected duration with the quote, and the heating is commissioned and working before the installer leaves.

Which boiler brand should I choose?

The honest answer: any of the major brands at the right size, installed well, will serve you. Differences lie in warranty length, parts availability and price tier. Our brand hub compares them factually — and a good installation matters more than the badge.

What size boiler do I need?

Size follows demand, not house pride: bedroom and bathroom count, radiator count and mains flow rate determine it. Oversizing wastes money and cycles the boiler; undersizing disappoints at the shower. The quote survey calculates it — our sizing guide explains the logic.