Heating
Most UK homes have gas-powered central heating systems. A gas-burning boiler heats a cylinder of water which is then pumped around the house in pipes to radiators where it heats the surrounding air. The warm air around the radiator rises causing a convection current which spreads the heat around the room. This technology is decades-old but can be very efficient, with modern condensing gas boilers achieving 90% efficiency (i.e. 90% of the energy in the supplied gas is converted to useful heat energy).
In rural areas without a gas network connection fuel oil is often used in place of gas, but the principle is the same. Electric boilers also exist but these are less popular in the UK because electricity is more expensive than gas per unit of heat, making them more expensive to run.
Gas boilers are gradually being replaced by more efficient electric heat pump systems. Heat pumps work similarly to boilers in the sense that they heat water which is pumped around the home, but this is done using a heat exchanger rather than by burning fossil fuels. They operate at lower temperatures which makes them better suited to under-floor heating than radiators. The uptake of heat pumps has been limited by the high cost of installation and the perception that they don’t produce enough heat to keep older houses warm. Both of these concerns are warranted - adding insulation and draughtproofing is essential first step if you are considering installing a heat pump in an older home.
Most radiators also feature individual thermostatic control valves which are supposed to switch off the radiator when the room reaches a set temperature. The intention is to allow room-by-room control of temperatures, however these are often unreliable leading to dramatically different temperatures between rooms. Upgrading to modern wifi-connected radiator valves will give you complete control of the temperature around your home, and also enables you to turn down the heating when you're out of the house. For tips on getting the most out of your heating see our page Optimise Heating Controls.
To see how much you could save on your heating bills by insulating your home, refer to our Cost Savings tables.
The central heating system is usually controlled by both a timer and a thermostat. The timer controls which hours during the days the system is "active". While the system is active, the thermostat checks the temperature and switches the heating on or off depending on whether the temperature of the house is above or below a specific temperature. Thermostats are typically set between 18-22°C so the thermostat will turn off the gas boiler if it detects that the house is already at that temperature or above. Reducing your thermostat by a couple of degrees is one of the most effective things you can do to reduce your energy usage. Most people will feel comfortable in temperatures of 18-20°C so you probably don't need to set it much higher than this.