New Boiler Installation in Cardiff
Swapping like-for-like — combi for combi in the same spot — is the economical end of the range; relocating the boiler, converting from a cylinder system to a combi, or upsizing for a loft conversion moves the price up. We'll always show you which parts of the quote are which.
Combi, system or heat-only — the honest steer
The rule of thumb that survives contact with reality: one bathroom and reasonable mains pressure, choose a combi; family house where two showers run at 7.30am, choose a system boiler and cylinder; ageing gravity system in a house you're not renovating, a modern heat-only swap can be the pragmatic move. A good installer measures your mains flow before recommending — if nobody's run a tap into a jug, the recommendation is a guess.
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
Manufacturer warranties on new boilers run 5–12 years depending on brand and installer accreditation — but they're conditional: annual servicing by a Gas Safe engineer, recorded. Your installer should register the warranty, notify building control (you'll receive the certificate), and complete the benchmark section. Keep all three documents with the house papers; missing paperwork is a genuine friction point in Cardiff conveyancing.
Water quality quietly decides how long heating components last around Cardiff. Cardiff's Welsh Water supply from Brecon Beacons reservoirs is soft — scale is a minor player, and the city's heating and hot-water work leans toward Victorian terrace pipework and the huge Cardiff Bay apartment stock. Where scale is a factor, protection on the boiler's cold supply and properly inhibited system water do more for the appliance's lifespan than any brand choice on the quote — and our engineers will say so.
Frequently asked questions
How much is a new boiler in Cardiff?
Most Cardiff 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.