Honeywell Home Evohome Hot Water Kit (8406H)

Each evohome controller is able to control up to 12 room heating zones and 1 hot water zone. Due to the control hierarchy within evohome, where for example, a room demand operates the room actuator and heating control relay then boiler relay, while hot water demand operates the hot water relay and then boiler relay, and due to different control algorithms used for hot water control, it is not possible to reassign a heating zone to hot water control. An additional hot water cylinder can be controlled independently by using separate timing and thermostat, or an additional evohome can be used (up to 4 can be used with the same boiler relay). Controlling 2 cylinders from one evohome should not be attempted, especially with unvented systems that need to be installed with due regard to Part G of the building regulations.

The ATF500DHW hot water kit can be used without the evohome controller but only manually, by pressing the button on the relay box in order to turn the hot water ON or OFF. It is not a recommended way of using the device since it was designed to be controller remotely through the evohome controller.