Radiators

Buying a radiator involves more than choosing a size or colour. These FAQs explain how to work out the heat you need, choose the right setup and material, find the best position and know what to check before you replace or fit one.

 

What size radiator do I need?

The right size of radiator depends on how much heat the room needs, which is usually measured in BTUs. Work this out using the room's dimensions and factors that affect how quickly it loses heat, such as windows, external walls and insulation. Then choose a radiator that provides enough heat while fitting the height, width and depth you have available.

Use our BTU calculator to work out what your room needs, or watch the video below for a quick guide to calculating BTU.

This video explains how to measure your room and which factors to consider when working out the heat output you need.

 

What's the difference between central heating and electric radiators?

Central heating radiators connect to a wet heating system, with hot water flowing through the radiator and back through the pipework. Electric radiators use electricity to produce heat independently, so they don't need to connect to central heating pipework.

Central heating models are a great choice when you're replacing or adding to an existing system, while electric radiators can be useful where extending pipework isn't practical or you want to heat a room independently.

 

Does radiator material matter?

Yes. The material can affect how quickly a radiator warms up and cools down, as well as its weight. Aluminium radiators tend to heat up and cool down quickly, while cast iron radiators take longer to warm but also cools more slowly. Steel is widely used across panel, column and designer radiators. Whatever the material, check the individual radiator's heat output to make sure it can provide enough warmth for the room.

 

How many radiators do I need in a room?

There isn't a set number. What matters is the total amount of heat the room needs. You can provide that with one radiator or split the required BTU between two or more new radiators if that works better with the size and layout of the room.

 

Where is the best place to put a radiator?

Choose a position where furniture, long curtains and other fittings won't block the radiator or restrict how heat moves into the room. Beneath a window is a common position for horizontal radiators, but it isn't the only option. Consider the available wall space, pipework and room layout, and leave the clearances recommended by the radiator manufacturer.

 

Can I mix different types of radiator in the same home?

Yes. Different rooms can use different radiator sizes, styles and orientations as long as each one works with the heating setup and provides enough heat for that space. If a central heating system contains radiators made from different metals, such as aluminium and steel, make sure the system uses a suitable inhibitor and follow the manufacturer's guidance. The system will also need balancing so each radiator heats properly.

 

What's the difference between BTU and watts?

Both are used to describe heat output. Central heating radiator specifications commonly show output in BTUs, while electric radiators are usually sized in watts. The important thing is to work out how much heat the room needs and compare that requirement with the output stated for the radiator you're considering.

 

What should I check before installing a radiator?

Check the radiator's dimensions, weight, connection positions and the type of wall or floor it will be fitted to. For central heating radiators, make sure the radiator valves suit both the radiator connections and the direction of your existing pipework. You should also leave the clearances stated by the manufacturer and check whether changing the radiator size or orientation means the pipework or fixings need moving.