Thermostats
Room Thermostats
Room Thermostats measure the air temperature around them, this enables them to regulate the heating system to constantly maintain the room temperature. When the room temperature falls below the setting, the thermostat switches on the central heating until the desired temperature is reached. Thermostats will only function when the programmer is switched on (calling for heat).
Room Thermostats are generally positioned in areas close to a home’s busiest spaces, such as the lounge or hallway, a room Thermostat should not be installed in a room with a radiator fitted with a TRV.
Programmable Room Thermostats
A Programmable room thermostat combines the room thermostat and programmer in one unit. Most programmable room thermostats are best suited to combination boilers because they only control your heating demands and not your hot water. Though a few such as the Honeywell CM907 will control hot water as well.
Cylinder Thermostats
A cylinder thermostat functions the same way as a room thermostat, except instead of controlling room temperature it controls hot water temperature in your hot water cylinder. The temperature of the hot water thermostat should be set at 60 degrees to combat any likelihood of legionella.
A cylinder thermostat should be fitted about 1/3 up from the bottom of the hot water cylinder and have a good contact with the copper body of the cylinder.
Some cylinder thermostats such as those fitted to unvented cylinders are more complex and should only be replaced by a competent person.