How a Modern Boiler System Works

In the UK today a Central Heating system is the most popular form of heating, found in around 70% of homes. However, the majority of households are unclear as to how a boiler functions and how it subsequently heats your home. It’s always beneficial to have a bit more knowledge on how something works, helping you to cope if, or when, it ever goes wrong!

Below the most popular heating systems within UK homes are explained, detailing how they work. After reading this article you will know a little more about this clever system that keeps you warm.

There are two popular central heating system used in UK homes, being a Combination Boiler (Combi Boiler) and a Systems Boiler.

Combi Boiler

This boiler has two appliances in one unit, combining both a pressurised central heating boiler and an instant water heater. This means you don’t need any separate elements to store water or heat water. A Combi Boiler gives you instant hot water when simply turning on the tap.

The Combi Boiler works by bringing in outside cold water from the mains water feed and passing it through the boiler’s main heat exchanger. This heats the water to 85 degrees C and then passes it through the secondary heat exchanger. This process heats the water up to then run through the hot water pipe and out of the tap. For your radiators, the Combi Boiler works in a similar way, but it only passes through the first heat exchanger before then being passed through to the radiators located around your house. A Combi Boiler is an adaptable system as you can have various features and sizes, suitably powered by different combustion fuels such as Gas, LPG and Oil fuels.

System Boiler

A System Boiler does not provide instant hot water as they use a cylinder storage unit. These are classed as a sealed system and work on a principle of stored water. This system works by the cold water tank, usually stored in your loft, releasing cold water into the cylinder. In turn the boiler heats water through pushing it around a series of coiled copper pipes inside the cylinder. These hot pipes create an energy exchange and subsequently heat the standing water in the cylinder for you to then use as hot water. These systems do not provide instant hot water, thus you will have to pre-program when you will likely need hot water in your household.

Each system has its disadvantages and benefits, outlined in a further posts in this blog, ‘What is a combi boiler?’.