Are you considering the Baxi Duo-tec combi boiler?

This boiler is a popular choice for many of my customers, and although it’s a step-down to the Platinum models, the biggest difference is that they come with a 7-year guarantee (instead of a 10-year one).

If you’re still unsure whether the Duo-tec combi range might be right for you, have no fear – that’s why I’ve written this review!

Introduction

I once fitted this particular boiler for a landlord with a small flat who lived abroad. He wanted decent guarantee, as he did not want to be at the mercy of his letting agent for repairs, so we looked at Baxi and Vaillant models for him. It turned out the Baxi Duo-tec was £190 cheaper than the Vaillant equivalent.

If you think this could be the boiler for you, read on, as below I’ve put together an overview of the entire Duo-tec range, as well as which output model is best suited to each type of home. This is particularly important, as getting it wrong could mean you’re either a bit too chilly in winter, or using more energy than you need.

So, without further ado, let’s take an in-depth look at the Baxi Duo-tec range, so you can get a feel for whether this is the right boiler for your home.

Output/flow rate

Firstly, let’s take a look at which outputs are available to your hot water and central heating, along with the flow rate you can expect to your taps:

• Duo-tec 24HE: 20kw to heating and 24kw to hot water: 9.8 litres per min at 35 degrees Celsius
• Duo-tec 28HE: 24kw to heating and 28kw to hot water: 11.5 litres per min at 35 degrees Celsius
• Duo-tec 33HE: 28kw to the heating and 33kw to the hot water: 13.5 litres per min at 35 degrees Celsius
• Duo-tec 40HE: 33kw to the heating and 40kw to the hot water: 16.4 litres per min at 35 degrees Celsius

TIP: In order to be confident you’re making the right choice for your home, I always recommend getting your chosen Gas Safe registered heating engineer to measure your home’s heat loss – it’s better to be safe than sorry!

PLEASE NOTE: If you decide to go for the 33 or 40kw boiler, always ask your engineer to check your incoming water pressure and flow rate before fitting, as you will NOT experience these brilliant flow rates if your incoming pressure is not up to scratch.

Size and special features

With measurements of 780mm high x 450mm wide x 345mm deep, the Baxi Duo-tec combi range is bigger than a compact model, so will not fit in Edinburgh press or standard kitchen wall cupboard.

This boiler can be used with Baxi’s twin flue system, which means your boiler can be located in positions other brands can’t – the long flue can easily be fitted through a ceiling or void.

Guarantee

The Baxi Duo-tec range comes with a 7-year no-quibble guarantee, and unlike other brands, you don’t need to fit Baxi’s filter and controls. Your guarantee stays valid as long as your boiler is serviced annually by a Gas Safe registered engineer.

Ideal for

Best pay attention to this part, as I’m about to give you a rough idea of which boiler specification is best suited to your home (but to be 100% sure, always request a heat loss measurement first!):

Duo-tec 24kw combi: Ideal for a small property with 3 – 4 radiators and a shower (although it might be a bit slow to fill a bath).

Duo-tec 28kw combi: Perfect for a small property with 1 – 2 bedrooms and around 4 – 6 radiators, with a shower and bath.

Duo-tec 33kw combi: Ideal for a 3-4 bedroom family home with around 6-10 radiators, high pressure shower and a bath. This is a very good flow rate for your shower and will easily fill your bath.

Duo-tec 40kw combi: Ideal for large flat with high ceilings, or a detached house with a bathroom and ensuite. Will happily heat 9-14 radiators, and will easily run 2 showers at once. You can also fill a deep cast iron bath without any problems.

ERP rating

The Baxi Duo-tec combi boiler is ERP rated A with an efficiency of 89%. It’s not the best efficiency rating of all the Baxi boiler ranges, but it’s not too shabby, either.

Conclusion

The Baxi Duo-tec combi range of boilers is the next step-down from the Baxi Platinum range, although the biggest different here is the 7-year guarantee (compared to 10 years for the Platinum).

My overview above gives you the full low-down on each model specification, included the heating and hot water output and flow rate, size and special features, guarantee, ERP rating and more.

I’ve also included a guide to help you decide which particular model might be ideal for your home – but don’t forget to ask your chosen heating engineer to conduct a heat loss test and check your incoming water pressure to make sure!

What are your thoughts on the Baxi Duo-tec combi boiler range?