The ENGO EMOD-ZB is a compact ZigBee 3.0 relay module that gives a wired heating system a wireless switching point. Wired to a 230V pump, zone valve, thermostatic actuator or wiring centre, it lets an ENGO EONE or E25 thermostat call for heat over ZigBee instead of a control cable. This is useful when adding a zone to an existing manifold, retrofitting a room with no wiring route, or bringing a hard-wired control box under app control.At 40 x 40 x 20 mm it fits inside a standard back box, and the DIN rail holder supplied in the box lets it clip straight into a manifold cabinet alongside the wiring centre. Power is 230V AC 50Hz with a 230V AC switched output rated 3(1)A. An LED shows operating status, and a single function button handles manual switching, binding and factory reset.Pairing works two ways. Added to a ZigBee 3.0 gateway such as the ENGO EGATE-PRO, the module appears in the ENGO Smart or Tuya Smart app for scheduling, remote switching and Alexa or Google Home voice control. Used with ENGO binding, it links directly to a compatible thermostat and keeps switching whether the system is online or offline, so the heating does not stop because the broadband has.Every powered module also works as a ZigBee repeater, acting as a mains-powered router that extends mesh range and steadies the signal to thermostats sitting further from the gateway. In a larger property that is often the difference between a reliable zone and an intermittent one.In the box: EMOD-ZB module, DIN rail mounting holder, quick guide. A ZigBee 3.0 gateway is required for app control and is sold separately. Installation must be carried out by a qualified electrician. Indoor use only.