A room thermostat preferably a timed or programmable one.
Combi boiler room thermostat.
The boiler only operates if both the programmer and thermostat are on.
A programmable thermostat for a combi boiler need only control the heating as the hot water is instantaneous.
When heat is required the thermostat connects these two wires together applying the full mains voltage to the switched line terminal.
The table below shows a selection of standard and smart programmable thermostats from honeywell baxi ideal nest tado and drayon.
Trvs are those nozzles located on the bottom of radiators usually with numbers 1 5 and an asterisk on them.
You can find out more about combination boilers and the best brands on our dedicated combi boilers page.
This is the same operation as the volt free system except in this case line voltage is applied to the controls and boiler.
While your boiler thermostat and room thermostat are ways to control the temperature of your entire home and hot water thermostatic radiator valves trvs allow you to manage the temperature of individual rooms.
This is called a single channel programmer.
A 2 wire thermostat is connected between line and the switched line terminal on the boiler.
Water is heated in a special chamber of the boiler which is usually powered by gas or fuel oil and is then distributed to different rooms of the home via radiators or other heat distribution systems installed.
3 wire thermostat and programmer.
A boiler interlock motorised valves.
Thermostatic radiator valves in all rooms except the one with the room thermostat.
The location of the thermostat is very important as the following examples show.
They work by automatically sensing the air temperature and when the temperature falls to a pre determined setting the thermostat will tell the heating to turn on.
If the thermostat is also activated the sl terminal on the boiler is connected to line and the boiler operates.
This activates the boiler.
We have a great range of wireless thermostats available that make it easier to control your heating remotely.