The ENGO Controls E25 smart thermostat is a Zigbee wireless room thermostat designed for use within the ENGO smart heating system.

Underfloor Heating Control:
When paired with an ENGO control box, the E25 controls individual underfloor heating zones by room. Each thermostat measures the room temperature and sends heating demand wirelessly to the control box over ZigBee 3.0; wireless binding to the control box is set up through an ENGO gateway (sold separately). The control box then operates the thermal actuators on the underfloor heating manifold, allowing precise zone control throughout the property.

Radiator Heating Control:
When paired with ENGO smart radiator valves, such as the ETRV-M30, the E25 controls radiator heating room by room. The valves physically open and close to regulate heat output. One E25 can control up to 6 smart radiator valves in the same room, and pairing them needs no gateway.

How it is controlled:
Heating schedules, timers and smart automation are created in the ENGO Smart app, which needs an ENGO gateway such as the E-Gate Pro (sold separately). Schedules are not set on the thermostat itself. Without a gateway, the E25 runs in day mode, with no schedule, from its three buttons (Up, OK, Down), which also set the temperature, pair radiator valves and hold installer settings such as TPI or hysteresis control and key lock. With the gateway and the ENGO Smart app you can also use voice control with Alexa or Google Home.

The E25 has two radios: ZigBee 3.0 (2.4 GHz) and a separate 868 MHz radio. The battery version runs on 2 x AA batteries (included) and needs no supply cables. The 230 V version has a volt-free relay output (COM/NO, 3(1) A, settable to NO, NC or off) that can be wired to a boiler, pump, actuator or ENGO ECB8-230 control box. The E25 is designed specifically for ENGO smart heating systems and is not compatible with other brands or generic Zigbee hubs.