Modern boilers certainly don’t come cheap; however they are an essential part of the home, which is why it is important that you choose the right boiler to meet your needs and requirements. Here we will provide information about the various different types of boilers available to help you identify your current system and choose your next boiler.
Combination boilers (Combi)
Over half of all boilers installed in the UK are combi boilers. As their name suggests, they provide two-in-one functionality, with both a high efficiency water heater and central heating boiler. A combi boiler produces domestic hot water directly from the boiler. The water enters as cold or pre-heated and leaves as hot as it goes into the tap. Hot water from the central heating system can also be pumped from the boiler around the radiators via a sealed circuit.
It is worth keeping in mind that domestic hot water is given priority. This means that when a hot tap is turned on, the boiler will devote its energy to heating the water for that tap. When the tap is turned off, the boiler will return to providing central heating.
Combi boilers have a sealed system, which means there is no need for bulky storage tanks in the loft or hot water cylinders that take up room in your cupboards. This type of boiler is suitable for most households (which is why they are so popular) however they are not particularly beneficial for larger homes, or houses with multi-occupants. This is due to the fact that combi boilers cannot cope with too many hot water outlets.
Regular boilers use a primary circuit, which means they directly supply the central heating system by sending water to the radiators and back again. The boiler warms the water for the taps indirectly using a coiled heat exchanger in the hot water cylinder.
The primary system is kept topped up by an expansion cistern in the loft, which also doubles up as an expansion tank with an overflow. The secondary water for the taps is kept topped up within the hot water cylinder, located by the cold water storage cistern in the loft. This is known as a vented system and is common in most UK homes.
Like regular boilers, system boilers also provide hot water directly for the central heating system by heating domestic water within a cylinder. The main difference is that their primary circuit passes through the heat exchange, before going to the radiators and back, like a sealed system. This means you do not need an expansion or feed cistern in the loft. Instead your system will be fitted with expansion vessels that facilitate and contain the expansion of hot water.
The hot water for your taps will be heated from a secondary circuit. This can either be an open vented system (which will require a cold water storage cistern) or a sealed and pressurised unvented system. It all depends on your choice of cylinder. The main benefit of a system boiler is that the hot water is located at the mains pressure.
In order to choose the right boiler, you will need to examine your current system and identify the pros and cons of each type of boiler. This is something that our team here at Priory Gas Heating can help you with. We will discuss your needs and requirements, as well as your lifestyle, to help you decide to choose the right boiler for your home. For more information about the different types of boilers available, feel free to contact us.