What are the different types of central heating systems?
There isn’t a one-fits-all approach when it comes to central heating systems, and the type of system that’s right for you could depend on all sorts of things, such as the location of your home, whether it’s connected to the gas grid, how many people live there, your hot water demand, the mains pressure, and more.
Below, you can find the types of central heating systems available, including wet systems, electric systems, direct heating and warm air heating. We’ve also looked at some of the most popular fuel types used for central heating, and provided some information around heat pumps.
Types of central heating systems
Wet central heating
Wet central heating is the standard system that most of us have in our home, though you may not have heard it referred to as a wet system before. This simply means that it uses water to heat up our radiators and provide heat to our home. You can also get wet underfloor heating.
Electric central heating
Electric central heating doesn’t mean that the system uses an electric boiler - this would still be considered a wet system as it uses water. Instead, it refers to the use of fully electric radiators, which can be infrared. These devices contain a special thermodynamic fluid, usually an oil, that heats up and expands when electricity is sent through it. They can be set to a programme, just like your boiler system, so that they come on and off at a time suitable for you.
Electric radiators don’t heat a room using convection, as wet radiators do, but through infrared. This type of heating works in a similar way to the sun - you feel warmed but the air around you doesn’t feel the same temperature. This is because electric radiators don’t heat the surrounding air, only the objects in the room, like you. For this reason, they’re very efficient and there’s a reduced feeling of cold spots or draughts.
You can also get electric underfloor heating (also referred to as dry heating) which works in a similar way and heats your whole home from the floor up.
Warm air heating
Warm air systems are most commonly found in the US because they can blow out hot air in winter and cool air in summer, but they can be found in some homes and commercial properties in the UK. Fans are generally located at the top of a wall and open and close their vents to allow air in.
District heating is less common but there are some systems like this in the UK and these could become more popular in a bid to meet net zero targets. Instead of relying on a heat source in your own home, such as a boiler, the heat is produced in a central location outside of your home and sent to multiple houses located within the district. There are currently around 500,000 homes in the UK being heated in this way. This means there is no need for a central heating system in your own home because the heat is supplied for you.
Fuel types for central heating systems
Gas central heating
Gas is the most common fuel type in the UK, currently, but this could be set to change, with the government clamping down on gas boilers in new homes. Gas boilers burn natural gas in order to produce heat for a wet central heating system, but homes must be connected to the gas grid in order for this type of heating to work. Currently, there are about two million homes that aren’t connected, so these will likely use electric or LPG alternatives.
LPG, which stands for liquid petroleum gas, is a liquid gas that can be stored in a tank for use by your boiler.
Electric central heating
We’ve already mentioned electric radiators as an alternative to a wet central heating system, but electric boilers mean you can keep the wet system and heat your home with something other than gas.
Electric boilers work in much the same way as a kettle, and use electric elements to heat water. It’s thought that these systems are greener than gas systems, however the majority of the electricity they use will likely be generated through the burning of fossil fuels. For this reason, they can only be truly green when they use mostly renewable energy.
Oil central heating
Oil-powered boilers are similar to gas, but there is no oil mains supply and so a tank must be located on your property somewhere. The oil is refilled by a large truck as and when you need it, but generally a tank should last a couple of months in winter (and longer in summer when your heating isn’t on). You’ll need to keep an eye on your oil levels as it’s not good for your boiler if it runs out completely. The system will need to be bled before more oil is added.
Biomass central heating
Biomass boilers aren’t that common but are still a viable option for greener heating. The boilers burn natural materials, including wood pellets and logs, to heat your home and create hot water. Burning these items does produce carbon dioxide, but it’s minimal in comparison to burning natural gas and the amount produced is similar to what the plant absorbed in its lifetime. This means that, if the plant was replaced, the process could be sustainable.
Types of heat pump systems
Boilers are no longer the only means of heating your home. Heat pumps have been increasing in popularity thanks to their ability to use renewable energy and their longevity. These systems will generally last longer than boilers and use natural warmth from the ground and air in order to heat your home.
Air source heating systems
Air source heat pumps draw in warmth from outside to heat your home. The warm air naturally heats up a refrigerant, which in turn is compressed to make it even hotter. This process can be done even when it’s as low as -15 degrees outside. The now-hot refrigerant evaporates and can be used to heat the water that is pumped through your radiators or underfloor heating. As the refrigerant cools down, it returns to a liquid and travels back to the heat pump unit to collect more warmth from outside.
Ground source heating systems
Ground source heat pumps work in much the same way as above, but they collect warmth from the ground instead of the air. The pipes that the refrigerant is located in are placed under the ground of your home, so as the fluid travels through the pipes, it picks up natural warmth and goes back to the main unit to be compressed. These systems may only work if you have a large garden or lots of land. In some cases, if you have a small garden, the pipework can be laid vertically in a borehole so it goes very far down, instead of taking up a large amount of surface area.
Water source heating systems
Not every home has access to natural water, but if you do, you could have a water source heat pump instead. These work in the same way as air source and ground source heat pumps, but they take their warmth from natural sources, such as rivers.
We’ve covered quite a few different types of systems in this guide, but hopefully it’s given you some good insights into the numerous central heating systems and which one would be best for you.