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18 Oct 2019
Owe Carter Owe Carter

Boiler alert! The best boilers to keep you warm this winter


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It’s not the most exciting of purchases, but having a good, reliable boiler to keep your home warm over winter is a must. Here we look at some of the best boilers on the market.

As unsexy as the topic of boilers may be, we all need one - and we need for it to be reliable. No one wants to have a cold home during winter, or lose their hot water at any time.

So if you’re looking to get your boiler replaced, it’s worth taking a bit of time to choose the right one.

But which is the best boiler for you? There are many options available, and it can be a bit confusing to figure out what's best. It depends, in part, on what type of property you live in. Although your intended usage and your area’s water pressure will also be factors.

Here we give a quick rundown of what boiler types are available and our top picks in each category.

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What is a condensing boiler?

By law, all new central heating boilers fitted in the UK must be condensing boilers. 

These boilers extract heat from the gases they spit out. Non-condensing boilers would lose this heat as they’re less efficient.

You can see what kind of boiler you have by looking at the flue. This is the pipe that carries the boiler’s exhaust outside the house.

If the flue is plastic and releases steam when the boiler is on, chances are you have a condensing boiler.

if it's a gas or oil boiler installed after 2005, it's likely to be a condensing boiler.

If the flue is metal and you can’t see any steam, your boiler is likely the non-condensing variety.

The good news is condensing boilers are easy to fit and tend to be energy efficient. A-rated condensing boilers have at least 90% efficiency ratings. Older boilers only convert about 60% of their fuel into heat*.

So A-rated condensing boilers use a third less fuel than older boilers. This means they cut your heating bills and CO2 emissions by a third* - great for your savings and the planet!

The different types of boiler

There are three main types of boiler. These are combination or combi boilers, conventional heat-only boilers and sealed system boilers

Combi boilers

If you live in a fairly small place, a combi boiler is likely to be your best bet. These provide heating and instant hot water directly from the boiler.

Importantly, these are nice and compact, as they don’t need additional water tanks.

They can also be more economical than conventional boilers, as they produce heat on demand - meaning they’re not using energy needlessly while not in use.

Plus they’re easy to install, which could mean you end up spending less upfront on an engineer.

Read more: Your energy questions answered
best boilers

Conventional heat-only boilers

Conventional boilers (or standard, if you prefer) can give you lots of hot water, but require two tanks - which take up a lot of space.

You tend to have a hot water cylinder, often in an airing room or suchlike. There’s also a cold water feed tank, usually in the attic.

If your home has a good deal of space, and two or more bathrooms, a conventional boiler might be your best option. If you need hot water in multiple places in your home at once, these tend to cope with the demand best.

Sealed system boilers

A system boiler also has a good capacity for producing hot water, and only requires one tank. The trade-off here, however, is the cost. These tend to be pricey.

However, they can be a life-saver if you live in an area with low water pressure, as they’re pressurised. No one wants a dribbly shower.

They’re also a good bet if you’re planning to have a loft conversion, because having a big cold water tank isn’t the best use of space in a regularly used room.

How powerful should my boiler be?

Boilers also vary in power, depending on your needs. When you get a heating engineer, let them know your requirements - such as if you want a nice powerful shower.

The engineer will also be able to tell you how powerful your boiler should be. But a quick and dirty tip here is to count your radiators:

  • If you have fewer than 10 radiators, you’ll need 27kW or under. This will probably be the case if you live in a one or two-bedroom flat or house with one bathroom.

  • Between 10 and 15 radiators should require a 28-34kW boiler. If you live in a three-bedroom semi-detached or terraced house with two bathrooms, this is likely to be you.

  • And if you have over 15, you’ll need 34kW and over. If you live in a detached house with four or more bedrooms, and several bathrooms, we’re talking to you.

Read more: The energy supplier switching process

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So which is the best boiler for me?

You’ve probably guessed by now that the answer is: it depends. Everyone’s needs are different, and so a certain amount of tailoring will be required. But we do have some recommendations.

As mentioned, combi boilers tend to be the best choice for smaller properties, both in terms of space and efficiency. But they’re still a good choice for normal-sized family houses, although you’ll need to choose something a bit more powerful.

According to consumer association Which?, the best overall boiler of 2019 is the Worcester Bosch Greenstar I ErP, which runs on mains gas or can be converted to LPG.

This scores 90% in its reviews. Although not the highest scoring combi boiler, this tops the table due to its value. It should set you back just over a grand, minus installation costs. 

Other highly recommended gas and LPG combi boilers include Viessmann Vitodens 050W (available in 29 and 35kW), 100W (26, 30, 35kW) and 111W (26 and 35kW) models.

These are closer to the two grand mark, but come with a 10-year warranty, and are particular favourites with engineers across the board.

These boilers also get the nod from Which?, as Viessmann was named the most reliable boiler brand in 2019. 

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If you’re shopping around, other well-respected combi brands include the Vaillant ecoTEC combi range; and Ideal, with its Logic, Vogue Gen2 and Vogue Max models scoring well in consumer reviews. 

If you live in a mid-sized family house with multiple bathrooms and a bigger demand for hot water, then it may be better to consider a conventional heat-only boiler.

Again, Worcester Bosch comes up trumps in Which?, with the Greenstar Danesmoor ErP+ range taking the top slots. 

If you’re after a system boiler, Vaillant ecoFIT and ecoTEC boilers are worth keeping an eye out for.

If you’re after an oil-fuelled boiler, Grant Vortex Eco External System 26-35 boilers are tip-top, as are Grant VortexBlue Internal Sealed System for bigger houses. 

But bear in mind that - although it’s a good idea to know which brands are recommended online - a qualified heating engineer will be able to make recommendations specific to your property.

Go smart

Increasingly systems around the house are becoming smart, so it’s not a terrible idea to integrate your heating and water too. Viessmann, for example, has smart heating systems that can be controlled by app.

Having heating you can control remotely has plenty of benefits. If you know you’re going to be home in twenty minutes, you can ensure it’s nice and toasty when you arrive using your phone.

This can also be really useful for maintenance. Boilers going on the blink can be frustrating and confusing. But having real-time diagnostics could help you identify any problems which arise, or even prevent them in the first place.

For more ways in which the home is becoming smart, check out our future of the home widget.

*Statistics are taken from the Energy Saving Trust.


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