Central Heating Explained

When certain things in our house break down or show signs of problems, we might have a general knowledge of how to go about fixing it. When it comes to central heating systems – for most people, they remain a complete mystery. While we might understand what each component does, not many of us know how the system fits and works together as a whole.

Modern domestic central heating systems will have the following components that the owner can adjust:





Diverter Valve


Hot water cylinder thermostat

Hot water cylinder

Central Heating Explained

Here is how they all function together as a complete unit:

The boiler is the heart of the system and has two important jobs – to heat your hot water tank and heat your home. For Boiler Installation Gloucester, visit http://www.hprservicesltd.com/gloucester-boiler-installation-and-heating-systems/

A programmer unit has a clock and two-time dials which can be set or programmed to turn the hot water and heating on and off at pre-selected times of the day or night.

When the programmer turns on the system, the boiler coming on is controlled by the room thermostat and a thermostat in the hot water cylinder. The thermostats are responsible for turning on the boiling when it’s required and turning it off again when it isn’t.

The diverter valve is a clever and important component that directs the flow of the hot water to either the hot water tank or the radiators depending on which thermostat is asking for heat. If you require both the heating and hot water, then the diverter valve will stick in the ‘mid-way’ position.

Did you know?

Boiler water is different from the water that comes from your taps. The water in your heating system and radiators is the same water, going around in a cycle until it is drained from the system by an engineer for some reason. The benefit of this is that the water can be treated with a chemical called an inhibitor, which prevents corrosion inside the pipework.

Central Heating Explained

The control dial on the front of your boiler is what sets the temperature of both the water and that which the radiators will reach. It’s important that this control dial is set at a higher temperature than that which is set on the cylinder thermostat. If it isn’t, the cylinder will never reach the desired temperature to be able to shut down the boiler.

One element that often confuses new boiler owners is that of the ‘pump over-run’. The pump continues to run for a couple of minutes when the boiler has been switched off. This is a clever mechanism designed to remove the danger of static water boiling from the leftover heat after the gas has been extinguished.