24kw Combi Boiler Guide – How Much And Which One’s Best?

Choosing the right boiler isn’t exactly easy. In today’s guide, we’re going to discuss 24kw combi boilers. In general, we’d expect these to be fitted in 2 bedroomed houses or flats.

Below we’ll be covering:

  • 24kw combi boiler prices
  • The best brands
  • Our top pick.
If you’re not sure if this size boiler is right for you, you can quickly fill out this boiler size calculator and the most suitable boilers will be listed towards the top.

Top Boiler Makes

There are literally dozens of boiler makes being supplied across merchants in the UK, some better than others.

We’ve already created a guide to the best combi boiler brands here. But in summary, you want to be heading for brands such as:

  • Baxi
  • Worcester Bosch
  • Ideal
  • Vaillant
  • Potterton.

Typically, these brands are known for excellent customer service, long warranties and building reliable appliances.

Picking Your 24kw Combi Boiler

That still doesn’t make your purchase decision easy. Each brand mentioned above will offer a range of 24kw boilers, so you still have plenty of choice.

You’ll want to narrow this down further by checking:

  1. Size

You need to decide whether you need a compact boiler. A compact boiler will fit snugly into a standard sized kitchen cupboard, rather than being wall hung. So, it’s going to make the room where the boiler is installed less cluttered and save space.

Examples of compact boilers include the Baxi 600, Ideal Logic Plus, and the Worcester Bosch CDi Compact.

  1. Price

Price is going to help filter your shortlist further. Typically, you’d expect all the top brands to be comparable on price. However, you will find that certain installers fit more of one brand than another, so can offer that specific brand at a slight discount.

One thing worth mentioning is HEATABLE. The company was founded with an emphasis on technology rather then salespeople, to keep boiler install prices down. That means HEATABLE supply and fit Worcester Bosch boilers at ridiculously competitive rates. You’ll be able to get a Worcester 25i fitted from £1,770 here, including a filter and smart thermostat. From other national installers, you’d be talking more like £3,000.

  1. Warranty

Although all the brands mentioned above are big on reliability, not all boiler models come with a long warranty. And generally, the warranty on offer speaks volumes for product quality. Even if it doesn’t, it guarantees you aren’t footing the bill for expensive repairs during the warranty period.

Some boiler models will come with a warranty as low as 2-years. We’d personally recommend heading for 5-years as a minimum; you’ll still have plenty of boiler options there.

As an example, HEATABLE mentioned above provide all Worcester Bosch 24kw combi boiler installations with a 10-year warranty, which is huge! Check their package out here.

The Best 24kw Combi Boiler

There’s a tonne of choice, and the best 24kw combi boiler is certainly up for debate. But as an overall package including warranty, price, product quality and extras included, we’d pick the Worcester Bosch 25i as topping the list.

Worcester 25i


Typically, Worcester Bosch boilers tip towards the higher-end price bracket compared with other brands, although they’re comparable to the likes of Vaillant and Potterton. An average installation here is likely to be in the region of £2,000.

However, due to the connection between HEATABLE and Worcester Bosch, you can find them cheaper. We plugged in some property details into this calculator and got a price that was well below £2,000.

Worcester Bosch Greenstar i from Heatable

Considering that includes an impressive warranty, filter for protection and an expensive smart thermostat, it’s an excellent deal.


Warranty is always a big deal maker or deal breaker for us. The Worcester 25i is leaps and bounds above most of the competition, coming with an impressive 10-year warranty.

You won’t be able to get this warranty with all local installers. The standard warranty is lower, and you’ll need to use an accredited installer, alongside certain Worcester branded parts.

HEATABLE have a relationship with Bosch, so they’re able to offer 10-years with all Worcester installations, as you can see here.

Frost Protection

Winter is the busiest time of the year for any Gas Safe engineer, simply due to the number of breakdowns.

One of the most common breakdowns relates to a condensate pipe blockage, which will lockout your boiler, and end up in an expensive repair bill from an emergency engineer.

Worcester aim to solve this problem with their CondenseSure. It helps to avoid condensate blockages by protecting your boiler down to -15°C for up to 48 hours.

Put simply, instead of condensed gases slowly dripping from the condensate pipe, the CondenseSure on the 25i releases them at speed, meaning less chance of them freezing over.


The options are endless when it comes to the types of controls you can use with the 25i. Obviously, you could go with a cheap looking (£40 or so) and manual thermostat from the likes of Honeywell.

However, most people nowadays tend to head for a smart thermostat. The two best options for 25i, are the Worcester Wave, or the Nest Learning Thermostat.

Currently, you can get a smart thermostat (around £200 value) fitted as part of an installation deal here, and it’s still well below £2,000.

Review Verdict

Overall, we put the Worcester 25i up there as one of, if not the best 24kw combi boiler.

It has an exceptional warranty at 10 years, can be fitted for under £2,000 and has plenty of useful features such as frost protection, not to mention it’s compatible with a wide range of smart controls.

Not sold on the 25i? You can compare multiple 24kw boiler prices from a range of brands here.

What’s Next?

Thanks for reading our guide to 24kw combi boilers, and our top pick.

If you want to read more on the 25i, we’ve already written a detailed Worcester 25i review here.

Got questions? Email us via our contact page, and we’ll do our best to help you out.




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