Dry, or forced air, central heating systems use a single gas or oil-fired furnace and a network of ducts through which the heated air travels throughout the building. In more modern systems, fans are often used to force the warm air to circulate more evenly from room to room. In each room there is a damper on the duct which can be used to control the local temperature.

Wet, or hydronic central heating systems use a boiler to heat water which is then circulated around the house through a network of pipes and radiators. This is by far the most common type of central heating system in use today.

Sealed Systems use a flexible diaphragm to compensate for the expansion of the water as it heats. These systems also incorporate a safety valve, which provide an escape route for excess water if the pressure inside the tank becomes too great. A non-return valve ensures that none of this water can end up in the mains water supply, and a topping-up bottle ensures that the water level can easily be brought back up to normal once it has cooled.

Although ceiling and underfloor heating systems are often referred to as being types of central heating systems, it is more common for them to use an independent electrical heating element rather than a shared heat supply. These systems work by using a combination of a heating element and a certain amount of insulation which both disperses the heat and prevents it from going out of the room.

Electric storage heaters are a popular choice in lower cost housing due to their cheap installation, maintenance, and running costs. They work by using a combination of an electric heating element and insulating ?fire bricks?, which can store and release heat energy over a comparatively long length of time. They are usually set to heat up during off-peak times when electricity demand is low and therefore comparatively cheap, and then release this heat slowly over the course of the day using fans or convectors. This is one of the cheapest ways to heat your home, although it is one of the least flexible for obvious reasons.