The ENGO E4i is a wired Wi-Fi room thermostat for water underfloor heating, in black. It has Wi-Fi built in, so it connects straight to your 2.4 GHz home network and the free ENGO Smart app with no gateway or hub. Set the temperature and your schedules from your phone, at home or away, or use the clear LCD and three buttons on the thermostat.

What it controls: the E4i has a switched 230 V output (SL, TRIAC) rated at 2(1) A. It wires directly to 230 V thermal actuators, or to an underfloor heating wiring centre such as the ENGO ECB8-230, without jumpers. TRIAC switching is silent, with no relay click. Please note the output is 230 V and not a volt-free relay, so it is not designed to switch a boiler directly or to carry electric heating mats.

Schedules: set four time periods a day, each with its own temperature, and copy a day to the next or give every day its own programme. The schedule is stored in the thermostat and keeps running if the internet connection drops. A short press switches to manual mode.

Heating and cooling: the 230 V CO input switches the thermostat between heating and cooling automatically from a heating and cooling wiring centre such as the ENGO ECB8HC-230. The same input can instead take a night setback signal from a timer. Control is TPI, with presets for underfloor heating, radiators or electric systems, or hysteresis from 0.1 to 2 degrees C either side.

More settings: setpoint range 5 to 45 degrees C with minimum and maximum limits, key lock with optional PIN code, valve protection and anti-stop, temperature offset and adjustable backlight. Works with Amazon Alexa and Google Home through the ENGO Smart app.

Specification: 230 V AC 50 Hz supply, terminals CO, SL, L and N, Wi-Fi 2.4 GHz, IP30, 80 x 80 x 23 mm. Model E4i-B. In the box: thermostat, backplate, 2 screws, 2 wall plugs and quick guide. Installation must be carried out by a qualified electrician. Indoor use only.