Central Heating Electricity Use
This page is aimed at those who have either oil or gas central heating but some of the points will be applicable to any central heating system that uses electricity. A simple saving is to switch off the central heating completely at the mains during the summer months if it is not required, saving at the very least the cost of running a time switch and possible any motorized zone control valves. The power used by the central heating system controller is likely to be between 1 and 5 Watts. For more information on oil or gas central heating look at setting up and balancing central heating and the associated pages on radiators.
Central Heating Pumps
Most systems use a pump to circulate the hot water which runs all the time the heating is operational. In a normal size installation this will use between 50W and 200W. The amount of power used is dependent on the pump speed which is likely to be variable, at least on modern pumps.. From experience quite a few are installed with the speed set to maximum (and hence maximum power consumption). Reducing the speed significantly, especially in a small property) may have very little effect apart from saving electricity. There is a down side to doing this - the heating does tend to take longer to reach temperature. To achieve the maximum savings the central heating system must be properly set up .
Motorised Valves In Central Heating
Also known as zone control valves, these are a good way to save heating energy by controlling different parts of the house BUT they do use electricity. There are some types which draw power continuously in one position, if this is the position the valve spends most of it's time in then you are wasting power. Playing with these valves is only for the competent but if you are having changes done to your heating system this is a good subject to question the heating engineer about to find out if he has considered this issue.
Central Heating Controllers/Time Switches/Time Switches
Modern central heating controllers consume only a small amount of current but electricity use adds up over time as they are on continuously, however there are still a large number of old style ones in use which can use up to 5W of power continuously so there will be scope for savings even taking into account the cost of replacement.
Central Heating Boilers
Central heating boilers have control circuitry in them which use electricity, how much is very dependent on the age of the boiler and it's complexity but could be between 2W and 40W. For this reason it is not a good idea to leave the boiler on permanently and rely on a room thermostat. If the boiler is used for heating hot water as well it is best to fit a time switch if one is not already fitted.