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Different Types Of Boilers [Explained] – Combi, System, Conventional Boilers & More

Welcome to our 5-minute guide to the different types of boilers available, and which one you’re going to need. After reading this guide, you’ll know the most suitable type of boiler to install in your property.

Do You Need A New Boiler?

We’ll also explain when it’s viable to switch to a different type of boiler from your current setup, and why.

Our Guide To The Different Types Of Boilers Available

Boiler Type: Back Boilers

We’re starting this guide, with a boiler type that’s not popular at all; back boilers (yuck!).

Why is this boiler a bust?

Because if you have a back boiler in your home, we’d advise switching and upgrading to a new central heating system, most likely one that incorporates a combi boiler.

What Is A Back Boiler?

If you’ve purchased a new property, you’ve looked for your boiler, and you’re stumped, there’s a good chance it’s hidden in the fire; that’s a back boiler.

These types of boilers were introduced in the 1960s and were fitted up until around the 1980s.

Needless to say, if you have a back boiler installed in your property, it’s going to be REALLY old. And with age, comes an incredible amount of heating inefficiency. Being ridiculously inefficient, it’s no coincidence that the big manufacturers no longer produce back boilers.

If you think you have this type of boiler, jump straight over to our guide to back boiler replacement here.

Or, you can get a heating engineer to help decide what the best route forward is, with a free on-site visit and quote here.

Boiler Type: Combi Boilers

Combis are by the far the most popular types of boiler.

And, that’s because they’re boilers most suited to small-averaged sized properties. So, that’s a 1-bedroom flat, a 4-bedroomed detached house, and pretty-much everything in between that requires heat.

What Is A Combi Boiler?

Combination boilers are an extremely efficient way to heat your home, and hot water as they require only a small amount of energy.

Combi boilers heat hot water on demand. So, as you turn up the thermostat, or turn on a tap or shower, the boiler heats water, just enough to supply you with what need.

The great thing about this type of boiler? You won’t need any kind of water storage facility with a combi boiler. And, that’s going to save space in your home. After all, cylinders aren’t exactly small; they’ll take up the majority of space in an average airing cupboard.

The popularity of combi boilers has meant that most airing cupboards are now redundant. If there’s capped off pipework in your airing cupboard, it’s likely the central heating system has been upgraded from one of the boilers below; a system or conventional boiler. After it’s been upgraded, the cylinder would have been removed.

We’ve created a couple of guides for you to read on the topic, including one on combi boiler prices, and the best combi boilers currently available.

And, you can get a boiler installation company to offer you free expert advice, with an on-site quote here.

Advantages Of A Combi Boiler

  • Instant hot water and heating
  • Many boiler brands produce compact combis that can fit in a small kitchen cupboard
  • No need for a hot water cylinder, saving you space
  • Energy efficient, saving you up to £305 per year on your utility bills
  • No cold feed in the loft, meaning no risk of pipes freezing during winter
  • Cheap to replace in comparison to other types of boiler

Boiler Type: System Boilers

Whilst most homes either have a combi boiler, or upgrade to one, that doesn’t mean there isn’t a place for other boiler types , including system boilers.

What Is A System Boiler?

A system boiler doesn’t work like a combi; it doesn’t heat hot water on demand. Instead, it fills up a cylinder.

Although there’s an obvious disadvantage to having to find space to install a hot water cylinder, there are some major advantages too.

In large properties with huge hot water demand, it comes to a point where it’s no longer viable to fit a combi boiler. We’re talking about properties where multiple taps and/or showers are running at once.

You’re really going to struggle to get the heating output from a combi, because sometimes,  those boilers just can’t keep up with the need.

So, if you have a system boiler with a hot water cylinder, and have high hot water demand, it’s unlikely it’s a viable option to switch to a combi; keep your current setup.

Sound like the type of boiler you need?

Check out our guide to system boilers, which covers everything you need to know about this type, including prices

Advantages Of A System Boiler

  • No need for a cold water tank in your loft
  • Ability to provide large volumes of hot water for your home, via multiple taps and showers
  • Perfect boiler for properties with multiple bathrooms
  • Can be used with an existing cylinder (when in good condition), meaning boiler replacement costs are similar to combi installations (cheap!)

Boiler Type: Conventional Boilers

You’ll hear conventional boilers being called a few different things. That includes heat-only, and traditional boilers.

What Is A Conventional Boiler?

Essentially, the conventional boiler, is an old-school version of a system boiler. But, instead of a simple water storage facility, it also needs a tank (usually located in your loft), to feed the boiler. Of course, that’s extra space.

Most popular boiler manufacturers still produce conventional boilers.

Whilst a system boiler might be a more viable option for your home, it’s likely a straight swap for a conventional boiler is the most cost-effective option, that is, if you don’t plan to alter pipework in your central heating system (i.e. lots of additional cost).

That’s because, an old and traditional central heating system might not be able to cope with the additional output and pressure, given out by newer system boilers.

But, this isn’t a one-size fits all approach. My suggestion, would be to get a heating engineer to spec your property, consider what’s currently installed (in terms of the boiler and the pipework), consider your demand for hot water, and then help you decide on the right boiler. You can go and get a site visit and quote here.

If there’s no risk of a system or combi boiler putting current pipework under too much pressure, it’s likely one of these will be a better fit in your home than a conventional boiler.

We’ve created a guide to conventional, heat-only and traditional boilers here.

Advantages Of A Conventional Boiler

  • Ideal boiler for properties with low water pressure
  • Due to water storage facilities, it can provide high volumes of water to multiple taps and showers
  • Not essential to upgrade to a combi or system, so no need to replace your full heating system

Boiler Type: Condensing Boilers

You’ll see some older properties with what’s known as a non-condensing boiler. This is a generic term and isn’t directly related to a specific boiler type (i.e. back, combi, system or conventional boiler).

What Is A Condensing Boiler?

Due to new building regulations, boilers need to meet certain energy efficiency requirements. Many of which, aren’t met by non-condensing boilers, due to their inefficiency.

When a non-condensing boiler is firing, it wasted lots of energy, via heat that’s expelled out of the flue. A condensing boiler recycles these gases, and heat. Essentially, it’s making use of energy, that would otherwise be wasted.

We’ve already written a detailed guide to condensing boiler prices you can read here. As well as flicking through that, you can get free on-site boiler installation quotes, from a qualified heating engineer here.

Home Installation Costs For Different Types Of Boilers

Now you know which type of boiler you need, the next question is, how much will it cost to install?

We’ve created a range of guides to help you. Also have a look at our new boiler deals.

Boiler Installation Costs Depend On The Kind Of Boiler You Get

If you own a back boiler, you’re most likely going to need to upgrade, check out our back boiler cost guide here.

For a typical gas boiler installation, including combi, system and conventional boilers, we’ve written a guide to boiler installation here.

But, if you’re off the grid and run on oil, check out our oil boiler installation guide.

Finally, if you have no central heating in your property currently (you’re using storage heaters, for instance), we’ve also created a guide to the central heating installation.

What’s Next? Still Have Questions On Which Type Of Boiler Is Right For You?

Still confused about the different boiler types, not sure which boiler is right for your home, or have a complex central heating system, and have questions about alternatives to boilers?

Need More Help With Your Boiler?

Check out our guides to getting a new boiler here – including some boilers prices. Or, we’d be happy to help, you can drop us a line via our contact page.

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