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What are room thermostats?

A room thermostat is essentially an integral thermometer and switch combined and is used to switch the boiler on or off as required to reach the user set temperature. A room thermostat works by measuring the surrounding air temperature and adjusting the boiler operation to suit the selected temperature (meaning a TRV is not necessary within the same room as the room thermostat).


Going wireless?


Room thermostats are also available in a wireless format, offering an easier and more flexible installation whilst keeping all the same benefits as a conventional wired thermostat. Care must be taken when deciding if a wireless design is suitable as there are a number of factors in determining the suitability of a wireless interface.


  • wireless room thermostatIn terms of installations a wireless thermostat is far easier to install and offers more flexibility as you do not need to connect the thermostat directly to the boilers location.
  • Like all wireless products some people may find problems with reception and ultimately responsiveness as many electrical items or radios located within the room may interfere with the thermostat's reception.
  • Since the actual thermostat is wireless, it can by nature be taken to any room in the house. Whilst offering a flexible alternative, if you bring it into your conservatory and forget to bring it out your heating will then respond to the temperature inside the conservatory, which in some cases may mean that your house will warm up to an undesired level.


Mechanical or digital?


mechanical and digital room thermostatsA mechanical or digital room thermostat generally refers to the way in which the temperature is recorded within the thermostat. In simple terms a mechanical thermostat works much like a normal mercury based thermometer, whereas a digital one works using a thermistor which then converts the readings into an accurate digital readout.


Given the basic design differences a digital thermostat (often referred to as a 'digistat') is inherently more accurate than a mechanical version. A mechanical thermostat can often maintain temperatures that are often 1°C higher than the set-point, which can inadvertently use up to 10% more energy. Mechanical thermostats are also slower to respond to temperature changes, thus occupant comfort levels are reduced quicker than if using a digital thermostat.


Also given the often inaccurate readings and slower response times you may assume that mechanical thermostats are no longer used. This is not altogether true as some people find the simplified design and user interactivity more appealing in a mechanical room thermostat over a digital variant.


Programmable room thermostats


A programmable room thermostat allows different temperatures to be set for different periods throughout the day, night or even week. A programmable room thermostat can offer this facility as it combines the function of a time switch within the thermostat, offering in effect a timed heating operation. A programmable room thermostat does also offer other features such as a 'night setback feature'.


programmable room thermostats

The main additional feature of a programmable thermostat over a conventional room thermostat is the ability to set different temperatures at different times of the day (known as comfort levels). By offering greater control and flexibility in the number of possible temperature set-points, a programmable room thermostat provides a better match to the occupants lifestyle and personal requirements.




By being able to actually program different comfort levels throughout the day it not only enables full control over your heating requirements but it is also a great way to improve energy efficiency. In addition Building Regulations now state that dwellings with total usable floor areas greater than 150m should have more than one heating circuit with separate time and temperature control. One efficient solution to this would be the addition of a programmable room thermostat.


There are a number of options available when choosing a programmable thermostat mostly dependant of the lifestyle requirements of the occupants. For example a full 7 day programmer may be required if the household is particular busy throughout the day with a number of different temperatures and times being required. Whereas as a more conventional 5/2 day programmer may be more suitable for people who don't need as many temperature changes throughout the day. 


An important benefit that a programmable room thermostat provides is the ability to set a night or day setback feature. This enables you to keep your home set to a desired overall minimum temperature throughout the day or night. This further improves energy efficiency as you heating is never kept to a fully off position and so your heating is used to 'top up' the heating requirements throughout the day, also increasing comfort levels. In addition to this some programmable room thermostats offer built in frost protection, i.e. if the temperature falls below a set level the room thermostat will call for the boiler to fire up.


For homes that feature independent how water and heating (non combi-boiler) some room thermostats enable you to control your hot water requirements from the comfort of your chair or at the least the same control box as your heating controls.


Ultimately a programmable room thermostat lets you choose what times you want the heating to be on, and what temperature it should reach whilst it is on. Not only this but you can also select different temperatures in your home at different times of the day (and days of the week) to meet your particular needs.

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