These are used with regular and system boilers where the programmer needs to control the heating and the hot water timing. (They can also be used with combi boilers where there are two separate heating circuits or a mix of radiators and underfloor heating). Load compensation takes the difference between the lower internal room temperature and the desired room temperature and adjusts the boiler’s output to close the gap as efficiently as possible. A programmable thermostat for a combi boiler need only control the heating, as the hot water is instantaneous. The table below shows a selection of standard and smart programmable thermostats from Honeywell, Baxi, Ideal, Nest, Tado and Drayon. This is called a ‘single channel’ programmer. The single channel (as in radio channel) is for the thermostat to send a signal to the boiler. NB these are compatible with heat only and system boilers however a separate control for hot water will be required. Under the new Boiler Plus regulations a new combi boiler must be fitted with an ‘advanced heating control’ (see below). wireless thermostats with programmers (non smart control)

Smart radiator valves will also individually control heat radiator, the difference is that the temperature can be controlled by a central programmable room stat. Smart valves can be grouped together to operate as a single circuit or controlled individually. They are a very easy fit to most radiators. Review and compare 32 thermostatic radiator valves by style and budget: standard, premium, chrome and budget. These work with regular and system boilers to control two separate heating circuits plus the hot water. These are only used in larger properties where the ground and first floors are separately piped to create two radiator circuits (called zones) or where there is a mix of radiators and underfloor heating. Load and weather CompensationThe conventional way is to fit Thermostat Radiator Valves (TRVs). This will allow you to control the temperature of each radiator, e.g. turning off radiators in little used rooms and turning them down in the bedrooms. This is a manual exercise but once done rarely needs changing. TRVs can be fitted to most radiators by a plumber. For a comprehensive review of 32 TRVs regard our Guide to Thermostatic Radiator Valves. Smart Radiator Valves Review and compare Smart Controls, including Boiler Branded smart controls, also referred to as remote heating controls, internet controls and wifi controls. A ‘channel’, like a radio channel, is the means by which the thermostat communicates with the systems it controls. New minimum efficiency standards were introduced in April 2018 aimed at reducing the amount of fuel we use to heat our homes. It is now mandatory for every new boiler installation to be fitted with a programmable room thermostat and, for combi boilers, an additional energy saving measure: Setting times for central heating and hot water to switch on and off can help reduce your home's energy consumption.

The common aim of all advanced controls is to ensure the boiler is on for the shortest possible time to meet the room temperature. Standard controls tend to overshoot the room temperature by 1 or 2 degrees which is very inefficient. Advanced controls reduce the heat output of the boiler as it approaches the desired temperature to prevent overshooting. The net result is a reduction is gas use and lower fuel bills. For all new a boiler installations a thermostat must be accompanied by a separate time control or programmer (or use combined a model see below). For existing installations it is still permissible to use a standalone thermostat. The table below shows standalone wireless thermostatic controls, but they will also be available in wired models. wireless thermostats with programmers (non smart control) Smart heating controls are all programmable thermostats that are connected to the internet and operable via a smart phone app. Most use some form of advanced heating control (i.e. weather compensation, load compensation and/or automation/optimisation features). Many are now compatible with Alexa, Apple, IFTTT and other smart home devices. This can provide additional functionality, for example you can turn your heating on and off via the voice activated smart home device or active geofencing sensors (the heating will come on as you near home via a GPS signal from your phone). NB some smart controls such as Nest and Tado come with geofencing as part of the device. For more on smart controls try our Guide to Smart Heating Controls or Guide to Home Automation Systems. 7) Zoning Advanced controls are also programmable room stats but have the addition of operating the boiler more efficiently during its periods of operation. Programmable thermostats for combi boilers

For smaller properties, the work and cost involved in re-piping the system to create two zones is rarely worth it. There are more cost effective, and less disruptive, ways of achieving variations in temperature. An additional energy saving measure must also be installed for combination boilers from the following list (a-c are all advanced heating controls):