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System or Regular Boiler: Which is Best for Your Home?

Becky Mckay
By: Becky Mckay
Updated: 25th October 2023

Best 32kW System Boiler

System and regular boilers have similarities, but are ultimately made for different homes and purposes. If you're unsure which boiler is best for you, we’ve created this simple 'system or regular boiler' guide to help you compare and decide which would be best suited to your home.

Both of these boilers are made for homes with high water demand and multiple bathrooms, but if you have just 1 bathroom a combination boiler will be your best option.

If you have two or more bathrooms, lots of inhabitants or just have a high demand for heat and hot water, read on to find out which of these powerful boilers is best for you.

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How do system and regular boilers work?

System boilers

System boilers are large, powerful heating setups. They come in two parts, the main boiler unit and an external hot water storage cylinder.
They work by taking water directly from the mains, heating it and supplying hot water to the radiators and an external storage cylinder. This cylinder provides an ample supply of hot water to support heavy usage in large homes (e.g. running multiple taps), and it differs slightly to the regular boiler.

Regular boilers

Regular (or conventional) boilers are a more traditional heating system, which you might find in some older homes. They are similar to system boilers, as they also have a main boiler unit and an external cylinder, but a regular boiler also has a large 'feed' tank which sits in the loft.

This feed tank is how the regular boiler gets its water supply. The tank is fed water from the mains, which is then fed down to the boiler to be heated. It's then sent on to radiators and an external hot water storage cylinder.

Both set ups are made to provide adequate supplies of hot water and heating, but they do take up a lot of space. If you don't need such a large supply there is an alternative option, the combi boiler. Visit our conventional or combi boiler guide for more information.

Should I think about a combi?

If you have just one bathroom and would prefer to save space, a combi boiler is definitely the best option for you. These boilers are much more compact, can provide hot water on demand and are the most popular choice for homeowners.

Combi boilers are connected directly to the mains, so they can heat hot water instantly and deliver to taps and radiators when needed. There is no storage or feed tank elements, so this makes them incredibly compact compared to their counterparts.

It's crucial to note, however, that you should only consider a combi if you have a single bathroom in your property. Whilst they are great for on demand use, they simply can't provide for the heavy usage of multiple bathrooms as effectively as system or regular boilers.

For more information about combis and how they compare to system boilers, read our helpful guide: Combi boilers vs System Boilers.

Benefits of a system boiler

We know that system boilers are great for larger homes, but there are also a lot of other benefits too.

  • Meets high demand for hot water
    With the benefit of an external storage cylinder there is always plenty of hot water ready to meet the demands of a home with multiple bathrooms.
  • Heats the home quickly
    The system set up includes a heating pump, which means hot water is continually circulated around the heating system and therefore warms up radiators very quickly.
  • Mains water pressure
    The pressure of your water will be stronger, compared to a combi, when multiple hot taps are being run at the same time.
  • Takes up less space than regular boilers
    A system boiler has no need for a water feed tank in the loft like a regular boiler, so it saves a lot of space and makes installation easier.
  • Can work with solar thermal
    As long as the cylinder installed is compatible, a system boiler can work with solar thermal energy. Which is great if you are looking for an alternative renewable energy source for your home. It can lower your heating bills and reduce strain on the boiler, leading to less faults and making it more reliable in the long run.

Why get a regular boiler?

Regular boilers might not be the first choice, as they are considered an older, more traditional system, but there are still benefits to these boilers.

  • New models are far more efficient
    Some modern versions of the regular boiler can now reach efficiency levels of up to 97%. That can mean huge savings on your bills and a reliable supply of hot water for larger homes.
  • Top choice for anyone living with low water pressure
    If you live in an area with low water pressure you could benefit from a regular boiler. It's ready-to-go storage of water can increase the pressure and flow rate to your taps.
  • Easier installation if you already have one
    If you currently have a regular boiler it is much easier to simply replace what you have with an updated version. It minimises disruption and reduces cost.
  • Can potentially work with solar thermal
    Solar panels can be connected to compatible cylinders which means there is potential to run them on solar energy.

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Disadvantages of system and regular boilers

The similarities between these heating systems means that they both have disadvantages that are also worth considering.

  • Space
    Both boilers take up a lot of room, as you need to find space for storage cylinders and feed tanks. However, you simply cannot adequately supply a home with more than one bathroom without that water storage.
  • Empty Cylinders
    Perhaps the biggest disadvantage of these boilers is the wait for hot water once the cylinder is empty. Unfortunately, once it's empty you have to wait for it to refill before you can get hot water again. It can be frustrating, but it just takes a bit of extra planning and you can optimise your usage so there's plenty left for taking a bath.

System and regular boiler installation

Installation may be one of the most important factors in your boiler decision. There are a lot of aspects to consider and a couple of key differences between what happens depending on the heating system you choose.

We've broken down the main aspects of installation when it comes to replacing different systems below. In addition, however, the engineer should also perform a powerflush as part of this work, so be sure to ask about this.

Replacing a regular boiler with a system boiler (approx. 2-3 days)

The main change when replacing a regular for system boiler is to remove the feed tank from the loft as it's no longer required. You would also need to install an unvented cylinder, this is somewhat different to the one a regular boiler uses, as they take their water supply in different ways.

Pipework would also have to be rerouted as the water supply changes. Instead of feeding the tank in the loft, the system boiler needs a direct water mains connection.

Replacing a system boiler with a regular boiler (approx. 2-5 days)

This type of replacement isn't recommended, as there are more elements to install at higher cost, more space usage and heavy disruption to reroute pipes. A homeowner should only consider a regular boiler if the property already has the correct pipework and space.

A system boiler will provide for the same level of water demand as a regular boiler and it is therefore not considered beneficial to make this kind of replacement.

Like-for-like boiler swap (approx. 1-2 days)

A direct upgrade of either boiler will be the most straight forward option. There would be no additional changes needed, unless any aspect (e.g. pipe work) needs replacing due to age or damage.

It's the perfect opportunity to upgrade elements, like cylinders or feed tanks, to newer models. In the case of the cylinders there is opportunity to upgrade to solar compatibility.

How much do they cost?

The price for a new boiler can vary depending on the type, brand and power output of the boiler you choose. You must also factor in the cost of installation on top of that. The full price including installation can be anywhere from £1,000 to £3,750.

We've created this brief table below to help you get an idea of what you may have to pay. You can find more information about cost breakdowns however, in our article about boiler prices and replacement costs.

BoilerAverage cost of boiler (without installation)Average installation costsEstimated cost of boiler fully installed

Combi £500 – £2,000 £500 - £1,000 £1,000 - £3,000
System £500 - £2,500 £500 - £1,000 £1,000 - £3,500
Regular £500 - £2,750 £500 - £1,000 £1,000 - £3,750

You can use our Boiler Installation Calculator to get a better idea of how much your unique installation could cost.

If you are considering a system or regular boiler, you should also factor in the type of cylinder or feed tank you will need, as these can also vary in price

Hot water cylinder costs

Both the regular and system boiler can only provide their greater supply of hot water with the addition of the hot water cylinder. Each system uses a slightly different type however, either vented or unvented depending on the way they are supplied water.

The best cylinders cost between £1,000 – £2,000, but there are some cheaper options available. Installation of the cylinder will also add to the overall cost by around £500, but this will depend on the size and model and where it needs to be fitted in the house.

You learn more about cylinder sizes, models and get free quotes here.

Water tank costs

Regular boilers will need a cold water tank fitting in the loft, which will add to the cost. Tank sizes vary depending on the size of the home and the usage demands, but most homes will need a tank that can store 25-100 gallons of water. These tanks can cost between £100 – £450 with an additional fee on top for installation.

Is a system or regular boiler best for your home?

We know that both system and regular boilers are best for homes with more than one bathroom, but deciding which is best for you can depend on your own needs and the physical aspects of removing or replacing your existing heating system.

You should only consider a regular boiler if you already have one and you're looking to update or replace it. There is really no benefit in trying to update a regular boiler with a system boiler, as they take up much the same space and a lot of pipework changes will really push up the cost and disruption.

However, if you have many bathrooms and a high demand for hot water in your home, a system boiler would be a perfect solution. It's more compact than a regular boiler, but can provide more hot water than a combi.

If it's time for you to update or replace your boiler, you can use our handy online form to get free quotes from trusted engineers in your area.

Becky Mckay

About the author

Becky Mckay

Becky has been a writer at Boiler Guide since 2021. Her vast boiler knowledge means she’s ready to help with any home heating query, big or small!

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