Baxi Duo Tec 28 Combi Boiler Review (Buying Guide for 2023)

If you’ve already read our overview of the Baxi Duo Tec boiler range, you’ll know we’re huge fans of Baxi boilers. Today, we’re going run through a quick review of the Duo Tec 28 combi. So, if you’re not sure if this is the right boiler for you, you’ll have everything you need to know to make a decision within the next 5 minutes.

What Size Property Is the Baxi Duo Tec 28 Designed For?

Before you go any further, it’s worth working out if the 28kW Duo Tec has sufficient heat output and flow rate for your property. 

The 28kW isn’t the smallest in the Duo Tec range; that would be the 24kW. The 24kw is designed for the smallest of properties, but we also need to take into account hot water demand, and the number of radiators.

And, you’ll need to consider the flow rates. The 24kW is low, at 9.8 litres per minute. This rises to 11.5 litres per minute for the Duo Tec 28. But, if that’s still not enough, you can jump to the Duo Tec 33, which provides a massive 13.5 litres per minute.

Typically, you’d expect to fit a 24kW in 1-2 bedroom apartments, flats, and sometimes, small terraced houses.

For homeowners with average hot water and heating demand, a 28kW is going to cover everything in the 2-3 bedroom range, sometimes even 4-bedroomed properties, depending on the size and number of radiators, as well as showers.

This might seem vague, but no property is the same. Feel free to get a general gauge of what size boiler you need here.

Another good option is to use Heatable’s boiler calculator, especially if you’d prefer a Worcester Bosch. Using their clickable multiple choice tool, you’ll get recommended boilers on screen, including installation costs.

The great thing about Heatable is they concentrate on technology rather than salespeople and house visits, and this helps keep boiler installation prices low.

Baxi Duo Tec Reviews Online

The best way to see how good a product is, is to go and check out online reviews, just like you would if you bought something off Amazon.

Unfortunately, most boiler sales tend to happen through plumbing merchants, so they’re not often reviewed.

However, you can find a Baxi boiler review on a cool little review site called Revoo. In fact, you’ll see over 450 reviews for the Baxi Duo eTc 28, with an average rating of 9.3 — which is pretty-darn’ good.

How Big Is the Baxi Duo Tec 28?

The next thing you need to decide is whether you need a compact boiler. If you need to install your boiler in a tiny space, such as a kitchen cupboard, the Baxi Duo Tec 28kW boiler isn’t suitable.

These are the dimensions of a Duo Tec combi are:

450mm (boiler width) x 780mm (boiler height) x 345mm (boiler depth)

To install this appliance, you’ll need a side clearance of 5mm, 200mm upper, lower of 150mm and 450mm front clearance for servicing.

Like I said, getting the right spec boiler, that also fits into the installation area, can be confusing. So, just get your boiler engineer to measure up when they’re there giving you a quote.

And, if you do need a compact boiler and like the Baxi brand, the Baxi 600 we mentioned above, is worth a shout. If you’re looking at the 28kW Duo Tec, it’s likely you’ll need the Baxi 630, not the 624.

Is the Duo Tec 28 Efficient?

It sure is, and it’s also Boiler Plus-compliant.

Baxi are up there with the leading boiler manufacturers in the UK. And, it’s not just reliability and competitive pricing that has allowed them to create a quality brand image.

Efficiency is extremely important. There’s little point saving a few quid by buying a cheap boiler, only to find you spend that saving 10x over, on energy bills, due to it being inefficient.

Baxi’s Duo Tec 28 is endorsed by the Energy Saving Trust, thanks to it’s 88.6% energy efficiency, giving it an A-rating. So, you’ll be saving a tonne of cash on energy bills, in comparison to your old and inefficient boiler.

How Long Is the Baxi Duo Tec Warranty?

With the Baxi Duo Tec 28, you’ll get a long, 7-year parts and labour warranty, and that’s plenty in our opinion.

In every single review written on this website, you’ll hear us banging on about warranty. We’ll do the same here.

Don’t buy a boiler with a low warranty. The boiler is only part of the overall installation cost. And saving a few hundred pounds now on a boiler with a low warranty (2-year, for instance), is going to come back to haunt you.

If a boiler was deemed reliable by a manufacturer, they wouldn’t offer a short warranty. At the end of the day, like you, they don’t want to pay for repairs.

So, you can bet your bottom dollar when the warranty runs out, that’s the time when there’s the biggest chance of something going wrong.

An installation cost of £1,800 or more? For things to start self-destructing after 2-years?

No thanks.

I personally wouldn’t buy a boiler with a warranty below 5-years. But, there are a tonne of brands offering boilers with a longer warranty than this. Where it’s cost-effective, get the biggest warranty you can.

Bear in mind you can get a Worcester at a similar price (or cheaper) with a 10-year warranty via Heatable.

Baxi Duo Tec Features Worth Mentioning

This year, we had a cold snap. In a single day, our site went from the average of around 2,500 visits, to over 20,000.

And, most of the people’s problems, related to a simple fault; a frozen condensate pipe. The condensate pipe allows condensed gases to escape from the boiler. Unfortunately, they can easily freeze, cause a blockage, and lock out the boiler.

The solution is to thaw out the pipe and reset the boiler. Or…

Buy a boiler with frost protection, which the Duo Tec 28 has.

The model’s frost thermostat ensures that boilers fitted in garages or lofts don’t freeze up. That means zero downtime, and no expensive call-out charges to get a boiler engineer to come and fix your appliance.

What’s the Price?

Baxi’s boiler prices are typically up there with the more expensive brands.

At the time of writing, the price of the Baxi Duo Tec 28kW sits at around £830, excluding costs associated with boiler installation. And that’s actually quite cheap.

Most would probably compare this with something like the Worcester 30i, which costs around £1,000 without installation, and the Ideal Logic Plus 30kW, which is priced around £800.

So, in terms of cost, the Baxi Duo Tec 28kW is competitive in relation to other boiler brand’s offerings.

How Much Will It Cost Including Installation?

Now, labour rates vary throughout the country, as does the complexity of a job.

Typically, we’d expect the installation price of a Duo Tec 28 to be in the region of £2,100-£2,200. That’s comparable in price to an equivalent Worcester installation from Heatable.

You can read our guide to boiler installation costs here. That’s going to give you a good idea of what adds on or reduces the cost of an installation like this one.

Should You Buy The Baxi Duo Tec 28?

With frost protection, reliable brass components, user-friendly controls, an A-rating in efficiency, and a long-ish 7-year warranty, the Baxi Duo Tec 28 certainly offers tonnes of value for money.

That said, you can get a comparable Worcester boiler installed from Heatable, with an even longer, 10-year warranty. The choice is yours.

The main downfall here is that the Baxi Duo Tec 28 is not compact. And who doesn’t want to save space? We’d be happy installing this, although for those needing a compact boiler, the new Baxi 600 is the way to go.

The best thing to do? Speak to a heating engineer. Don’t just get multiple quotes from different installers. If needs be, get quotes for different (but, suitable) boilers, and see how they stack up.

You can get up to 3 different boiler installation quotes here.

What’s Next?

Thanks for reading our review of the Baxi Duo Tec 28 combi boiler. Got a Duo Tec 28, and have an opinion? Still got questions about which boiler you should install?

Leave us a comment below and we’ll get back to you as soon as possible.