Heating Advice
Five Signs Your Cardiff Home Needs a New Boiler
Knocking sounds, rising bills and inconsistent hot water — here's when it's time to consider a replacement.
Read More →About Cosywarm
Established in 1976 and based in Whitchurch, Cardiff, Cosywarm Heating & Plumbing has spent nearly fifty years building a reputation as one of South Wales' most trusted names in domestic and commercial plumbing, gas, heating and electrical work.
We're Gas Safe registered, Worcester Bosch Group Accredited Installers and accredited by Which? Trusted Trader — and every new boiler we fit is backed by a 10-year manufacturer guarantee. From a dripping tap to a full bathroom or kitchen refit, our team of highly trained local engineers delivers a first-class service at an affordable price.
What We Do
Eight trades, one Cardiff-based team. From emergency boiler repair to a brand-new fitted kitchen, we cover every job our customers need — saving you the headache of juggling multiple contractors.
Leaking taps, blocked drains, appliance installs and all general plumbing work — domestic and commercial.
Worcester Bosch accredited installs for new builds and replacements, with a 10-year guarantee.
Expert fault-finding and repair across all major boiler brands, plus annual servicing.
CP12 landlord gas safety certificates and homeowner safety checks — fast turnaround.
Full system design, installation and repair — including radiators and underfloor heating.
Domestic and commercial electrical work, EICR inspections, certifications and emergency call-outs.
Complete bathroom design, supply and installation — including all plumbing and tiling.
Full kitchen fitting in Cardiff — plumbing, worktops, tiling and flooring all included.
24/7 Emergency Cover
One number, three emergencies covered — call us first.
Where We Work
Based at 112C The Philog in Whitchurch, Cardiff, our engineers cover every neighbourhood across the city and beyond — from the Valleys down to the Vale of Glamorgan.
Why Cosywarm
We've been fixing leaks, fitting boilers and rewiring homes across South Wales for nearly fifty years. That's not a marketing line — it's three generations of returning customers and the same trusted team turning up year after year.
Gas Safe Registered. Worcester Bosch Group Accredited Installer. Which? Trusted Trader. Each one demands continuous training, audited workmanship and customer references — we hold all three because cutting corners isn't an option.
Every new boiler system we install comes with a full 10-year manufacturer guarantee. No fine print, no asterisks, no "subject to" — a decade of cover from the day the engineer leaves your door.
Plumbing emergency at 11pm? Boiler dead before a frosty morning? Tripped consumer unit on a Sunday? One phone number gets a qualified Cosywarm plumber, gas engineer or electrician to your door — we cover all three.
Most plumbing firms hand you off to a tiler, who hands you off to an electrician, who hands you off to a fitter. We do plumbing, gas, electrics, bathroom and kitchen fitting in-house — one company, one quote, one finish date.
Every quote we give is free, properly itemised and exactly what you'll pay — barring genuine unknowns we'd never spot until the wall's open. No upselling, no "while we're here" surcharges, no shock invoices.
Boiler Servicing Plans
Spread the cost of an annual service over the year, lock in priority call-out, and keep your manufacturer warranty valid. Plans start from just a few pounds a month.
View Service PlansWhat Cardiff Says
Trustindex verifies that the original source of the review is Google.
The Cosywarm team replaced our old boiler with a new Worcester Bosch and sorted some radiator issues at the same time. Quote was clear, fitters were tidy and on time, and the 10-year guarantee gave us real peace of mind. Highly recommended.
Trustindex verifies that the original source of the review is Google.
Use Cosywarm for the gas safety certificates on all of my rentals. They are properly Gas Safe registered, paperwork is always sent through the same day, and tenants get on with them. Couldn't be easier — well worth the call.
Trustindex verifies that the original source of the review is Google.
Had a full new bathroom fitted — Cosywarm handled the lot, from removing the old suite through to plumbing, tiling and electrics. One team in and out, no hassle juggling different trades. Finish is spotless and the price was exactly what was quoted.
Trustindex verifies that the original source of the review is Google.
Boiler packed up in November — phoned Cosywarm first thing and an engineer was at the door before lunch. Diagnosed and repaired the same day. The price was fair and they explained everything as they went. Will use again.
Trustindex verifies that the original source of the review is Google.
Full kitchen fit — plumbing, electrics, tiling and flooring. The lads turned up on time every morning, kept the place clean, and finished within the week they quoted. Genuinely impressed by how seamless it was.
Trustindex verifies that the original source of the review is Google.
Needed an EICR done before selling. Booked, completed and certificate emailed across within two days. Friendly electrician, properly explained anything that needed sorting. Saved me a lot of stress with the sale.
From the Blog
Heating Advice
Knocking sounds, rising bills and inconsistent hot water — here's when it's time to consider a replacement.
Read More →Landlords
What CP12 inspections cover, how often you need one, and the legal implications of letting yours lapse.
Read More →Bathrooms
From measuring up to choosing fittings — how to plan a bathroom refit that lasts the next 15 years.
Read More →Got Questions?
Yes — Cosywarm Heating & Plumbing is fully Gas Safe Registered (the only legal gas industry register in the UK) and our engineers' details are publicly verifiable on the Gas Safe Register. Anyone working on gas in your home must be on this register by law.
Every new boiler system we install comes with a full 10-year manufacturer guarantee. As Worcester Bosch Group Accredited Installers, we're authorised to offer the extended warranty cover their non-accredited competitors simply can't.
Yes — emergency plumbing, gas and electrical call-outs are all available across Cardiff and South Wales. Call 029 2061 5111 and you'll speak to a real person who can dispatch a qualified engineer.
Absolutely. Every quote we issue is genuinely free — no obligation, no callout charge for the survey, and no pressure to proceed. We'd rather earn your business with honest pricing than chase it with hidden fees.
Our team is based in Whitchurch, Cardiff and we cover every Cardiff neighbourhood as well as the wider South Wales region — including Penarth, Barry, Caerphilly, Pontypridd, Bridgend and Newport. If you're unsure, just call us.
Yes — both. Our kitchen and bathroom fitting service is fully in-house, covering the strip-out, plumbing, electrics, tiling, flooring and final fittings. One team, one quote, one finish date — no juggling contractors.
Fill in the form below and a Cosywarm engineer will be in touch — usually within the same working day.
Cardiff-based plumbing, heating, gas and electrical company established in 1976. Worcester Bosch accredited, Gas Safe registered, Which? Trusted Trader — covering Cardiff and the wider South Wales region.