Gas Heating Systems
There are two main types of gas heating system, what differs is the way they provide hot water:
A gas heating system generally has the following main elements:
The timeswitch tells the boiler when to be "on", they can be programmed to be "on" at different times. The boiler will provide heat when it is "on" and the room thermostat tells it to, ie when the room that the thermostat is in falls below the desired temperature.
The room thermostat will tell the boiler to produce heat when the room it is in falls below the desired temperature.
Turning a room thermostat to a higher setting will not make the room heat up any faster. How quickly the room heats up depends on the design of the heating system, for example, the size of boiler and radiators. Neither does the setting affect how quickly the room cools down. Turning a room thermostat to a lower setting will result in the room being controlled at a lower temperature, and saves energy.
The heating system will not work if a time switch or programmer has switched it off.
The way to set and use your room thermostat is to find the lowest temperature setting that you are comfortable with, and then leave it alone to do its job. The best way to do this is to set the room thermostat to a low temperature – say 18oC – and then turn it up by one degree each day until you are comfortable with the temperature. You won’t have to adjust the thermostat further. Any adjustment above this setting will waste energy and cost you more money.
Thermostatic radiator valve (TRV)
The room thermostat is situated in one room. It may therefore be calling for heat when other rooms are warm enough. A TRV will sense the air temperature around them and control the flow of water through the radiator which they are fitted to.
They should be set at a level that gives you the room temperature you want. These settings may have to be different in each room, and you should set the TRVs to suit each room and then leave them to do their job. Turning a TRV to a higher setting will not make the room heat up any faster. How quickly the room heats up depends on the boiler size and setting, and the radiator size. Turning a TRV to a lower setting will result in the room being controlled at a lower temperature, and saves energy.
TRVs need a free flow of air to sense the temperature, so they must not be covered by curtains or blocked by furniture. TRVs cannot turn off the boiler when the whole house is warm, that is the room thermostat's job. The radiator in the room with the room thermostat should not normally have a TRV, but, if it does, keep the TRV on the maximum setting and adjust the room thermostat as required.
Programmable Room Thermostat (PRT)
Some systems will have a PRT instead of a boiler timeswitch and room thermostat. A PRT is both a boiler timeswitch and a room thermostat.
A PRT lets you choose what times you want the heating to be on, and what temperature it should reach while it is on. It will allow you to select different temperatures in your home at different times of the day (and days of the week) to meet your particular needs.
For systems with a combi boiler, the boiler will heat water as you require it. There are no controls for the boiler for this.
For stored water, the boiler timeswitch will control when the boiler produces hot water.