Different types of boilers and their benefits

Whether you are planning to replace your old boiler or buying a new one, it is important that you understand the different types of boilers available. This is even more important if you are moving to a new property. Different types of properties require different categories of boiler based on their size and type. We will list out all types of boilers with their pros and cons.

Combination Boilers

This is a traditional boiler type which works on-demand basis. Water is directly heated from the mains whenever you open the tap. There is no need for any storage tank or cylinder. Since there is no storage, it occupies much lesser space. This is highly suitable for small size properties. These are highly energy efficient as it only works for a specific period, there is no need to heat and store water regularly.


  • Compact
  • Energy efficient
  • Delivers hot water in high pressure for a powerful shower


  • No option to store hot water
  • Lacks efficiency when more than one shower/taps are being used simultaneously.

Conventional boilers

These are the regular boilers which require a hot water cylinder for heating and storing water. In some cases, 2 storage tanks are used one for feeding the hot water and the other for centralized heating. These are suitable for older apartments which don’t have high-pressure water supply. Since hot water can be stored they are beneficial for homes which have more than one bathroom. This can simultaneously deliver consistent hot water for multiple showers at the same time. They consume more energy if not used efficiently. Once the water drains out completely from the tank, it takes a considerable amount of time to refill and boil again.


  • Hot water can be stored
  • Single boiler can service more than one bathroom
  • Suitable even for old properties


  • Not energy efficient
  • Takes time to refill and boil

Also read:  Things to consider before buying a new boiler

System boilers

System boilers are also similar to conventional boilers but are much more efficient and smaller in size. This requires hot water cylinder storage, the only difference is that the storage is built inside the boiler itself. All the modules of the boiler including the storage and cylinder are bundled inside the boiler which occupies a much lesser space. They are much more energy efficient and can supply hot water consistently across multiple showers simultaneously. This is best suited for apartments which have multiple bathrooms.


  • Cost-effective
  • Compact
  • Delivers hot water across bathrooms simultaneously

Immersion heaters

These are electric heaters which perform similarly to your electric kettle. Immersion heaters are small metal coils that are positioned inside a big hot water cylinder filled with water. It has its own power source and heats the water only when required. This is largely used as a backup to your combination boilers. They can come in handy when your main boiler fails.


  • It comes with a thermostat so that it can automatically switch off when the water temperature reaches a certain level.
  • It comes with a well-insulated jacket, so the water is stored hot for a longer period of time


  • Consumes a lot of more energy than its gas counterparts.

Chose your boiler type based on the size of your apartment and the frequency of usage.