A cold water feed or expansion tank is situated higher than the hot water cylinder, usually in the loft or attic.

In addition, each room can have Open Window Detection turned on. This uses an algorithm to detect when a draft is detected, suggesting an open window or door. The heating is then turned off to conserve energy. Combi boilers only allow for one hot tap, bath or shower to be running at a time, by running more than one it will significantly reduce the pressure to each, which can be a problem for larger households with high demand for hot water. Four 22mm or 28mm copper pipes connected to the boiler (sometimes three pipes if an injector T is fitted, but a fourth 22mm or 28mm copper pipe will still be nearby). The Heat Hub is a rectangular box with two buttons. One button activates the set-up process, while the other starts the whole system heating. LEDs above the buttons glow green when these options are active. The Heat Hub should be screwed to the wall next to your boiler. The square smart thermostat has a two-inch screen that shows the current temperature of the room it’s in, as well as the desired temperature. It also displays the relative humidity and battery level, and features a flame icon to indicate if the heating is switched on. Wiser allows you to build up your heating system as you go. Add smart plugs and radiator thermostats as required. By creating more independent heating zones, you can optimise your comfort and save energy.This type of system is effectively an upgraded gravity-fed system, where the central heating has been upgraded to be fully pumped, while the hot water remains gravity-fed. This type of upgrade allows separate central heating and hot water timer control, unlike standard gravity-fed systems, due to the addition of motorised valves and a cylinder thermostat. CHARACTERISTICS OF CONVENTIONAL BOILERS (with vented hot water and fully pumped) There’s no difference in how the devices work, and Drayton provides all the fixings in the box to connect its TRVs to any radiator with an existing manual TRV. If your radiators don’t have TRVs, you’ll need a plumber to add them. Alexa and Google Home support means that you can control your heating using your voice. Alexa recognises individual rooms so that you can adjust the heat automatically, and you can also find out what the temperature is in each room.

Although the TRVs make a small humming noise while operating, I found that they were very quiet in operation. Once I was used to them, I could easily sleep while they operated. A room thermostat controls the heating in your home. If the room's temperature drops below your chosen temperature, the thermostat will switch on. Once the room has reached the chosen temperature, the thermostat will turn the heating off, preventing overheating and reducing energy consumption. This can help reduce your home's energy consumption. If, however, but turning on the central heating side, the hot water also turns on, this would indicate a gravity system. ADVANTAGES OF CONVENTIONAL BOILERS (with vented hot water and fully pumped) Thanks for the detailed response. I havent decommissioned the downstairs thermostat but given its just a dial, I think all it does is set the max temperature rather than dictating when to come on - the Drayton must have taken control in that case as it comes with its own digital thermostat to place in a given room. You can tap on a room and edit the schedule or access the room settings, where you can view the battery level for the thermostat, rename it and turn Open Window Detection on or off. Editing a schedule was made super-easy as a result of the ‘copy’ feature, which lets you duplicate a schedule with just one tap, rather than having to input it all for each day and on each device.

There’s no geolocation built into the app to set Away mode automatically, although the IFTTT channel does let me automate this. I have my system turn on Away mode when the Abode alarm turns on; when the alarm turns off, I have Wiser turn Away mode off. If you have a gravity-fed system, Wiser will only be compatible if it is fully pumped, by that we mean upgraded with motorised valves and a cylinder thermostat. Comfort Mode is there to make sure that your home hits the target temperature at the set point rather than turning the heating on at that point. In other words, if you get up at 7:30am and set a schedule to have your heating at 18°C at this time, your house will be warm when you wake up. HubR: Fixed wiring only, to comply with current IET regulations (BS7671); Room and radiator thermostat: No wiring required

Timer and thermostat control of the central heating is available independently of the hot water, due to a cylinder thermostat fitted to the hot water cylinder. However, it does have an Away Mode. Rather than switching the heating off completely while you’re out, this feature allows you to set a minimum temperature at which you want your home to remain at while away. If the temperature plunges below this threshold, the heating will spring to life – handy, if you're concerned about frozen pipes when you’re not at home. These smart radiator thermostats replace the TRVs (thermostatic radiator valves) on your radiator, the type that let you adjust the temperature of the radiator manually. If you don’t have TRVs then you’ll need to bear the cost of changing your current valves to TRVs on top of the cost of the smart heating system. There’s no denying the radiator thermostats are bulkier than TRVs, but we found we didn’t notice them as much as we expected to. Consists of a central heating boiler and a separate, pressurised hot water tank fed directly by the cold water mains feed, so the tank heats and stores hot water at mains pressure.HubR: User: Push Button/LED; I/O: Mains Relays (1-3), Digital Boiler Interface; Room thermostat: User: TFT display, touch buttons; I/O: None; Radiator thermostat: User: Twist Cap, LED; I/O: None Honeywell Evohome gives more flexibility, with its custom actions and IFTTT channel. Its radiator thermostats are also more fully featured, letting you set the temperature you want from the room. If you want the most powerful and flexible multiroom heating system, then, we’d recommend Evohome. With the standard kit, you get two TRVs and one room thermostat. If you start with this, you can put the TRVs into your most heavily used rooms for individual control, and the room thermostat elsewhere in the house to control everything else. That’s neat, as you can start with the cheap kit and then upgrade as you see fit to add TRVs to every radiator in the house. Once you’ve done that, the room thermostat can be used to control a room and all TRVs in it, as Wiser supports rooms with multiple radiators.

There’s also an Away mode, where your heating is set to a reduced temperature (configured by you). This mode is handy when you’re out or on holiday. There’s only manual operation of this, but you can use the IFTTT channel to build your own geolocation service, either for one device or, with a service such as Life360, for your entire family.GRAVITY-FED SYSTEMS (conventional systems with vented hot water cylinder and non-pumped central heating) Gravity-fed systems are no longer fitted new and do not comply to current building regulations, therefore homeowners are increasingly opting to replace older gravity-fed systems to either combi or fully-pumped conventional boiler systems. CHARACTERISTICS OF GRAVITY-FED SYSTEMS (non-pumped)