How Central Heating Works

A lot of people don’t fully understand exactly how central heating works. This is probably due to the fact that there is never an ‘overall’ user instruction manual for heating systems. You will get individual leaflets for say boiler, controller, and even for thermostat but there is nothing that can help you understand the central heating system as a whole.

Major Components Of A Central Heating System

A regular domestic heating system has seven major components. To understand this system, you first need to understand each part and learn how it works. Only then you can you understand how central heating works.

  1. Boiler: This is the easily the most important part of the entire central heating system as it heats the water, which ultimately heats your home.

  2. Programmer: This part helps you take control of heating as you can turn on the hot water in the heating system using this part.

  3. Room thermostat: It controls the temperature of the water by turning the boiler on/off to bring room temperature close to desired temperature.

  4. Hot water cylinder thermostat: This thermostat works essentially the same as a room thermostat. The only difference is that it is located inside the water cylinder and not the room.

  5. Radiators: This is where the hot water/air releases energy and become cold therefore making the room hot.

  6. Diverter valve: This valve controls flow of water from boiler.

  7. Hot water cylinder: The boiler water flows through hot water cylinder inside a pipe. As a result, the water in the cylinder heats up.

  8. Pump: As name suggests, this parts pumps water around different channels in the heating system.

How Central Heating Works – The Basic System

Understanding how each part in a central heating system works is critical to learning how central heating works. There are mainly either wet heating systems or dry heating systems.

Wet Heating System – How It Works

A central heating system makes use of a primary heating appliance, often a boiler or a furnace, to deliver heat throughout the building. A wet heating system pumps water through pipes to room radiators. Here is how this heating system works.

  • Boiler heats the water.

  • Hot water is pumped around the pipes to radiators.

  • Valves control how much water is sent to radiators depending on the settings on thermostat and indoor temperature.

  • Water releases heat in the house/building through radiators. It’s then pumped back to boiler where it’s reheated and the cycle is repeated.

Dry Heating System – How It Works

These systems use warm air instead of water to heat the indoors. Here is how it works.

  • A boiler heats air.

  • Hot air is blows through large ducts to the building.

  • You can open/close and adjust airflow in these ducts to control hot air coming from the heating system.

Boilers can make use of different types of fuels to heat water/air, depending on the type of central heating system installed in your home/office. They can burn methane gas or make use of liquid petroleum gas. Below is a list of all fuels that can power your heating system.

  • Methane gas or liquid petroleum gas

  • Coal or wood

  • Electricity