Boiler swaps & installation

A new boiler is one of the bigger purchases you’ll make for your home, and the choice you make today is the heating system you’ll live with for the next decade. We don’t rush that conversation, and we never push you toward a more expensive boiler than you need.

What’s included as standard

Every boiler install we do includes the same baseline. We don’t strip kit out of cheaper packages and try to upsell you back to it.

• Gas Safe-registered engineer carrying out the work end-to-end
• Magnetic system filter (MagnaClean Professional 3 or equivalent) on every install
• Power flush of the existing system if it needs one; we’ll show you what’s coming out before we charge for it
• Smart wireless thermostat (Worcester Wave, Vaillant vSMART or Honeywell evohome), paired and tested before we leave
• Manufacturer warranty registration handled by us, in your name
• Building Regs notification submitted to Cardiff Council via Gas Safe within 14 days
• Old boiler removed, packaging taken away, dust sheets up the whole time

The bits that some other firms call “extras”, flue extensions up to 3 metres, condensate trace heating, isolation valves on the gas and water, are baseline on our quotes. If something genuinely is an extra (a major flue rework, a soft-start motor for an apartment block) we’ll tell you up front and price it line-by-line.

Brands we install

We’re approved installers with Worcester Bosch, Vaillant (Vaillant Advance) and Viessmann, which means extended manufacturer warranties of up to 10 years on most installs. We also fit Ideal and Baxi where it’s the right call for the budget.

Worcester Bosch: the safe pick

Worcester is what we fit in maybe 60% of Cardiff homes. The Greenstar 4000 and 8000 ranges are well-priced, parts are everywhere (we carry most service parts on the van), and the 10-year warranty through accredited installers is the longest in the mid-market. If you want a boiler your kids could service in 2036, this is the one.

Vaillant: the engineer’s pick

Vaillant build their own components in Germany, and it shows. The ecoTEC plus is the quietest combi we install, barely audible from the next room. Vaillant Advance gives us the 10-year parts-and-labour warranty, and we’ve never had one of these come back inside warranty for a major fault. Slightly more expensive than Worcester but it’ll outlast it.

Viessmann: the premium choice

If you’re staying in the home for 15+ years, Viessmann is the long-game pick. Stainless-steel heat exchangers (Worcester and Vaillant use aluminium) mean genuinely lower long-term degradation. Vitodens 100-W is the entry model; the 200-W is what we install when someone wants the best.

How long does it take?

Most combi-to-combi swaps are completed in a single working day, 8am start to 4–5pm finish. System or regular boiler upgrades, or installs that need a flue route changed, take 1–2 days. Back-boiler removals add half a day for the chimney sweep and asbestos check.

We’ll give you the firm timeline at quote stage so you can plan around it. We don’t start a job we don’t have time to finish.

What does it cost?

Combi installs start from £1,895 including the boiler, the labour, and everything in the standard inclusion list above. That’s a Worcester Greenstar 30i or equivalent in a like-for-like swap. Larger system upgrades, Megaflo cylinder installs and powerflushes are quoted on a fixed-price basis after a free survey.

Pricing is as transparent as we can make it: see the bands above for the bracket your install will land in. No hidden fees, no surprise extras at the end of the job.

Common mistakes other firms make

We get called out a lot to fix new boilers other firms have just installed. The patterns we see:

• Wrong size. A 28kW combi in a 4-bed house can’t keep up with a shower running while the kitchen tap’s on. The fix is upsizing to 32–35kW, but it should never have been wrong from the start.
• No magnetic filter. Saves the installer £80 on the job, costs you a clogged heat exchanger in year three. Every modern boiler manufacturer specifies one in the install instructions; some installers ignore it.
• No powerflush on a sludged system. Bolting a £2,000 boiler onto a 20-year-old radiator system full of magnetite is the fastest way to void the warranty.
• Cheap thermostats. A wired stat costs £30; a smart thermostat costs £180. The smart one will pay back the difference in winter heating savings within 18 months.

We don’t cut these corners. It’s why our installs cost slightly more than the cheapest quotes you’ll see, and why our boilers don’t break down in year four.

Will my warranty actually be honoured?

Only if the install is registered correctly with the manufacturer, and only if the boiler has been serviced annually by a Gas Safe engineer. We register every install in your name within 7 days; we send you an annual service reminder; and the service can be done by any Gas Safe engineer (not just us) without affecting cover.

If you ever have a warranty issue we’ll handle the manufacturer call on your behalf; that’s part of what you’re paying for.