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Gas Boilers

The gas boiler is the most important part of a central heating system. It's like a big fire that has a continuous supply of gas streaming into it from a pipe that goes out to a gas main in the street. When you want to heat your home, you switch on the boiler with an electric switch. A valve opens, gas enters a sealed combustion chamber in the boiler through lots of small jets, and an electric ignition system sets them alight. The gas jets play onto a heat exchanger connected to a pipe carrying cold water. The heat exchanger takes the heat energy from the gas jets and heats the water to something like 60°C (140°F).

There are three main types of Gas Boiler. Information on each is given below:

Combi Boilers

A Combi, or combination boiler, is by far the most common boiler type in the UK.  They are both energy efficient and cost-effective as they only heat water when it is required and do not require a separate tank to store hot water. As the name suggests, a combination boiler combines a water heater and a central heating boiler and they are a fantastic choice for flats and small to medium-sized houses where there is not demand for hot water by multiple users at the same time. This type of boiler has an additional heat exchanger which allows water to be heated on demand from the mains supply which means that it will not run out. This also means that, providing that the mains water supply to the property is adequate, it is possible to run a powerful shower without the need for an additional pump.

As combination boilers are small and compact, and do not require feed or expansion tanks, hot water cylinders or cold water storage tanks, they can be fitted into almost any property. This can potentially free up a lot of space if you are switching from an alternative system to a combi boiler.  

As combi boilers rely on mains water pressure to supply the hot water around your home, it is possible to experience a lower flow rate if you silmaltaneously run multiple hot water outlets at the same time. It is also necessary to check that the mains flow rate to your property is sufficient for a combination boiler to work

Conventional Boilers

A conventional boiler, also known as a regular or heat only boiler, is used in the more traditional system. This system utilises a cold water storage tanks, hot water cylinder and feed and expansion tanks.  As this type of system creates a store of hot water, it is suitable for properties where there will be multiple demand points for hot water at the same time. These systems often include a separate hot and cold water pump which allows water to be distributed rapidly around the property when needed.

The use of a separate pump means that these sytems are often suitable for properties where the mains water pressure is low. They are also suitable for properties with older radiator sytems which would be unable to cope with the high water pressures that combination boilers work at. These systems are also suitable for use in conjunction with solar panels which are used to heat water.

System Boilers

A System boiler is very similar to a conventional boiler and they both require a hot water cylinder. The main difference is that a system boiler has many of the major components of the system contained within it. This means that system boilers are often faster and easier to install. By using a system with an unvented cylinder, it is also possible to install a system which does not require a cold water storage tank. This can provide a significant reduction in space requirements and is especially suitable for properties where a loft conversion is planned. Overall, system boilers are ideal in homes with high hot water usage and the installation can be neater as a result of the boiler’s inbuilt components.

If you have a breakdown on your existing gas boiler, please call 0800 142 5204
and one of our friendly customer support advisors will do everything they can to help get an engineer out to you as soon as possible

With your boiler often being the most important appliance in your home, the impact of a breakdown can be very distressing and inconvenient. We know that when your boiler breaks down, you want things back to normal as soon as possible. We will do everything we can to make sure that your boiler is back up and running as soon as possible. We will always tell you beforehand what the call out charge will be and we will keep you fully informed of any additional costs throughout the repair so that there are no unexpected bills.

If you would like to talk to us about installing a new gas boiler

Please call our customer services team on 0844 445 7998 to discuss all of your options