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Which Boiler Is Best: Combi, Conventional, or System?


Choosing the right boiler for your home is a big decision. Not only does it impact your energy bills, but it also sets the stage for your heating system's performance over the next few decades. That's why it's crucial to make a choice you feel confident about.

There are three main types of domestic boilers: combi, conventional, and system boilers. Each has its own perks and drawbacks, and the best fit often depends on your property size, the number of bathrooms, and your hot water needs.

At M J Burt, we specialise in installing energy-efficient boilers across Dorset. Read our guide below to discover the ins and outs of each boiler type, so you can make a decision that's right for your home.

Combi boilers

Combi boilers, short for combination boilers, combine the functions of a water heater and a central heating boiler into a single compact unit. Unlike conventional boiler systems, combi boilers don't require a separate hot water cylinder or storage tank. Instead, they heat water directly from the mains supply on demand, providing hot water instantly whenever a tap or shower is turned on.

Pros of combi boilers

  • Combi boilers don't require a separate hot water cylinder or cold water tank, making them ideal for homes with limited space.
  • Combi boilers can be more energy-efficient because there's no need to preheat the water and store it.
  • Combi boilers generally provide high-pressure hot water since they draw water directly from the mains.
  • Combi boilers are relatively quick and easy to install, especially in smaller properties, as they don't require a separate storage tank.

Cons of combi boilers

  • The water is shared between your hot water taps and central heating, so using hot water simultaneously in multiple outlets may reduce the flow rate.
  • Combi boilers are compact and may struggle to meet the hot water demands of larger homes with multiple bathrooms.

Conventional boilers

Conventional boilers are made up of a boiler unit, a hot water storage cylinder (usually located in an airing cupboard), and a cold water tank (usually in the loft). They heat water and store it for later use.

Pros of conventional boilers

  • Conventional boilers are often better suited for larger homes with multiple bathrooms, as they can provide a higher volume of hot water.
  • They can supply hot water to several taps simultaneously without a drop in water pressure.

Cons of conventional boilers

  • Conventional boilers may take longer to provide hot water since it needs to be heated and stored in the cylinder. Once the stored hot water is used, there may be a delay before more hot water is available.
  • They require separate hot and cold water storage tanks, which can take up space in your home.
  • Installing a conventional boiler can be more complex due to the need for multiple components and the associated pipework.

System boilers

System boilers work similarly to combi boilers, bringing most components together into a single unit. The main difference is they require a separate hot water storage cylinder. The boiler warms up water and keeps it ready in the cylinder until it's needed.

Pros of system boilers

  • Like combi boilers, system boilers don't require a water tank in the loft, making them suitable for properties with limited space.
  • System boilers are pressurised, and the hot water is delivered at mains pressure. This means they can provide a stronger and more consistent flow of hot water, making them suitable for multiple bathrooms and higher floors.
  • System boilers are generally quick and easy to install, as many of the components are built into the unit, reducing the need for additional external tanks and equipment.

Cons of system boilers

  • Although system boilers provide hot water at mains pressure, the amount of hot water available is still limited by the size of the storage cylinder.
  • While system boilers save space by eliminating the need for a loft tank, they still require space for a hot water cylinder, which may be a problem in smaller properties.

Expert boiler installations in Dorset, Poole, and Bournemouth

Replacing your old, inefficient boiler can be daunting, but the experts at M J Burt are here to make it simple. With over 35 years of experience, our Gas Safe™ registered team have the knowledge to design, supply, and install the perfect new heating system for your home.

Whatever boiler you're looking for, we'll work carefully to optimise its performance, minimise disruption during installation, and provide a friendly, reliable service from start to finish. We also provide scheduled maintenance and repairs to keep it working its best in the future.

Still not sure which boiler type is best for you? No problem! We'll assess your needs and provide our expert recommendations, so you can have total confidence in your new system.

If you're ready to upgrade your old boiler for a modern, energy-efficient model, let's get started. Get a free quote online or call us on 01202 721955 today!

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