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)

TOP TIP make sure your advanced heating control is compatible with your preferred boiler. If the advanced control uses weather compensation, load compensation or both then the control and the boiler must be able to communicate with each other in the same ‘language’. Most boiler manufacturers use a bespoke language that means only their ‘compensation’ controls can work with their boilers. Some boiler and control manufacturers have adopted the ‘Opentherm’ language which means that differ products, such as a Honeywell control and Baxi boiler can speak with each other. See our Guide to Opentherm products and alternative controls 4) Which control do I need to comply with Boiler Plus? Review and compare 32 thermostatic radiator valves by style and budget: standard, premium, chrome and budget.All Honeywell ST9400 models incorporate the Line of Text (LoT™) display that gives clear plain English instructions whenever any button or slider is used. This means that installers, customers and users can operate all of the controls reliably, without needing to find an instruction manual. Read our guide on wireless heating controls , both standard and smart controls, and the boiler plus scheme. 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. If you want to set different times on different days, you will need what is called a ‘seven-day’ programmable thermostat. Combi, heat only and system boilers are compatible with programmable thermostats but you will need to factor in hot water controls if you have a heat only or system boiler.

Weather compensation works in the same way but uses the external temperature. This traditionally involved a temperature sensor on the outside of a property linked to the internal programmer/thermostat. The sensor is able to forewarn the boiler of a change in outside air temperature which will eventually lead to a decrease or increase of inside temperature. Traditional programmable room stats turn the boiler on and off, for example if you only want your boiler to come on in the mornings and before you get home from work as well as set the room temperature. A standard central heating programmer (or programmable thermostat) will allow you to set the boiler to come on at the same times each day, for example, from 6am – 8am and 5pm until 9pm. require the same time and temperature control but with an additional ‘advanced’ energy saving feature, i.e weather compensation, load compensation or smart controls that combine automation and optimisation features. (Or a flue gas recovery unit) New installations of a combi boiler: Conventional zoning is really only worth undertaking in larger properties. It involves piping two heating zones, usually ground floor and first floor. Each zone is controlled by a separate thermostat, allowing you to set different temperatures on each floor thus saving energy. For example, 21 degrees downstairs and 16 degree upstairs. The Honeywell ST9400C Two Channel unit is a 7 day full programmer that gives great flexibility offering up to three on/off switchings per day, additionally each day can be programmed differently, which is ideal for when the user has different heating needs from day to day. The Honeywell ST9400C can be set to 5/2 day or 1 day programme during installation.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: Slightly different minimum requirements apply depending on boiler type (combi, heat only or system) and whether the heating control is being fitted to an existing installation or fitted as part of a new boiler. The boxes below set the requirements according to your circumstances. Remember to fit a compatible Boiler Plus product. If you are fitting a new boiler with a smart heating control we strongly recommend you review our Guide to the Best Smart Controls or Guide to Opentherm products and alternative controls for non-smart products. New installations of a heat only or system boiler: The 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 A programmable room stat will have commonly have one (single) or two (twin) channels, although some have three. The first channel will control the boiler. The second channel will control the hot water. These are used with combi boilers, as it is not necessary to control the hot water separately (this is done by the boiler).

Every boiler installation must have an ErP efficiency of at least 92% (see our Guide to Boiler Efficiencies). 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.

A thermostat sets the desired room temperature whilst a programmer gives the user great control of the times the heating is on. A programmable room thermostat is a combined unit that does both. There are two main types of programmer: 1 day and 7 day (although some with a 5/2 day options). Most programmers will allow you set 2-6 time periods per day and also set different temperatures for each time period. If you only have a thermostat then your boiler will fire on and off all day unless 1) you turn the thermostat down when you out or 2) you switch the boiler off when you go out. Single Channel and Twin Channel Programmers d. Flue gas recovery unit - this sits above the boiler and recovers heat from the flue. It is reported to reduce gas consumption by upto 4%. At their most basic, heating controls tell the boiler to come on and go off via a room thermostat. A room thermostat is set to the desired temperature and it will tell the boiler to come on until that room temperature is reached. Once reached, the thermostat will tell the boiler to go off again. These take the form of a digital display or a dial thermostat. 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 Compensation A ‘channel’, like a radio channel, is the means by which the thermostat communicates with the systems it controls.