What are heating controls and how do they work?
The heating controls in your central heating system are designed to allow you to control the temperature of your home and to use energy efficiently. For the controls to be effective you should be able to turn them on and off and they should rapidly react to any changes in room temperature. If you have thermostatic heating controls in each room they should provide varying levels of heat in different parts of your home, at levels set by you, and stop your boiler from working when it is not needed.
What do heating controls actually do?
The main parts of your heating system are:-
Radiators enable the heat in the hot water generated by your boiler to be released into a room through convection of the surrounding air. So that the room is not too hot or too cold the radiator should be appropriate for the size of the room and if you have a new central heating system each room will need to be assessed. You should ‘bleed’ your radiator if you notice it is not as warm as it should be. Radiators also have valves to restrict the flow of hot water (see the section on valves and thermostatic valves below).
Radiator Valves. Valves are provided in radiators to enable you to shut off or restrict the flow of water. This can be in an emergency following a water leak or when you wish to remove or replace the radiator. Turning the valve in a clockwise direction should close down the flow and turning anticlockwise will restore the water flow.If you plan to remove the radiator you should also close the valve on the other side of the radiator to completely seal it off prom the main plumbing.
Thermostatic radiator valves (TRVs). These act similar to radiator valves but they also control the temperature of each room separately. To achieve this they sense the room temperature and reduce the flow of water into the radiator when it reaches the required temperature. They tend to work best in rooms which get too hot or are used infrequently. As they work independently of the main room thermostat you can achieve a more precise control of individual room temperatures and hence reduce energy consumption.
Programmers or time-clocks are the most useful controls for controlling the temperature and energy usage. They can they turn your heating and hot water on and off depending on the times you set. More advanced programmers can have a different on / off pattern for weekdays and for the weekend. To be fully effective they should be capable of controlling the heating and hot water independently so that, say in the summer, you can still have hot water when the heating is off. Of course if you have a combi boiler then it produces hot water on demand so you need only be concerned about switching off the heating. Also look for the ability to advance a cycle and immediately turn on either the heating or the hot water without disturbing the programmed schedule.
Room thermostats automatically switch your heating off once the chosen temperature is reached and bring it back on if the temperature in the room falls. To save energy you should set your room thermostat to the lowest comfortable temperature. In domestic properties this is usually 18°C – 21°C. It is surprising to learn that lowering a thermostat by just 1°C can cut up to 10 per cent off annual heating bills.
A thermostat controls the temperature of the air in the room where it is positioned. They need a free flow of air to detect the ambient room temperature, so they must not be covered by curtains, blocked by furniture, or positioned near to drafts and direct sunlight or other sources of heat. You should also not put a thermostatic radiator valve on the radiator with the room thermostat or the operation of the two thermostats will interfere with each other producing unexpected effects.