What does size mean in terms of boilers?

‘Size’, in the context of boilers, refers to kilowatts (kW). A “larger” boiler will have a larger amount of kWs; it will not necessarily be physically bigger. It is very important to keep in mind that you should purchase a boiler that suits your and your home’s needs; buying a boiler that has a larger kW than you need will only waste the fuel and will become a long-term financial burden. Likewise, it is also important to not try to save money by buying too little, as you will run out of hot water.

Types of boiler

Your boiler type will impact which size boiler you will need, due to how the different types of boiler are made. Before purchasing a boiler, you should consider which boiler type you have and which one would be beneficial for your hot water needs. The three types of boiler are:
-Combi boiler: A combi boiler is the most common type of boiler found in UK houses. Combi boilers are most efficient for small houses due to only heating the water you need.
-System boiler: A system boiler heats your hot water and heating system through a water cylinder, typically located in the attic. System boilers receive their water directly through the mains which is very useful for large houses.
-Conventional boiler: A conventional boiler heats your hot water and heating system through a water cylinder. Conventional boilers are useful for older buildings that may not be able to handle higher boiler pressure.

Count your radiators

One way to determine what size boiler you will need is to count your radiators. For example, if you live in a one-bedroom bungalow, you will need a smaller boiler than a 5 bedroom house, due to having a larger demand for hot water. Below are estimates to what size boiler you need, depending on the type of boiler, and how many radiators you have:

Combi boilers:
-Up to 10 radiators: 24kW – 27kW
-10 – 15 radiators: 28kW – 34kW
-15 – 20 radiators: 35kW – 42kW

System and Conventional boilers:
-Up to 10 radiators: 12kW – 15kW
-10 – 15 radiators: 18kW – 24kW
-15 – 20 radiators: 30kW – 40kW

Combi boilers require more energy due to heating the water instantly, unlike system and conventional boilers. It is very important to know which boiler type you have so you can ensure you purchase the correct size boiler, using the estimations above.

If you have any concerns or would like a boiler installed, please do not hesitate to contact Bradford Boiler Company at 01274 317169 or at info@bradfordboilercompany.co.uk.