• Home Heating & Hot Water Automation

    13th July 2016 | Blog | David
  • Automationlogo-large

    In this article, we outline the basic steps to add home automation / intelligence to an existing home central heating & hot water system. The system is a modern pressurised/sealed central heating & water system. It was controlled by a Honeywell ST9400C programmer.

    Honeywell ST9400C

    The heating system is to be integrated into a Z-Wave Home Intelligence system, controlled by a Fibaro Home Centre 2 Hub/Server. Z-Wave continues to set the standard for automated lighting, heating, security, appliances, and other smart devices. It is consumer-focused, secure & easy to setup & use, both in the home and all-importantly: away.

    In order that both the Heating and Hot water is controllable, a Fibaro dual Z-Wave relay unit is used. Part# FGS-222.

    warning-signs Before embarking on ANY electrical work, the circuit MUST be switched off & isolated at the Consumer Unit. If in doubt, consult a Qualified Electrician.

    With the power to the boiler & programmer isolated, the panel is removed for inspection of the existing wiring.

    before wiring IMG_2269

    The existing controller sits over a deep 47mm single wall box, so there was plenty of room to add the Fibaro Z-Wave 2 x 1.5 kW relay unit.


    The existing wiring was connected up using ‘chocolate strip’ connectors. These were replaced with WAGO connector blocks and all of the multi-wire conductors ferruled, in accordance with the 17th Edition of the IET Wiring Regulations [526].

    wagos IMG_2270

    The Z-Wave Dual Relay was wired in, taken the CH On as the input to switch#1 and HW On as the input to Switch#2.

    Screen Shot 2016-07-12 at 17.00.33relay IMG_2271

    The original programmer’s plate was then re-attached to the wall box, with care taken to ensure the antenna of the Z-Wave dual relay unit, is not trapped or obscured. It is also important to have clear, safe access to the ‘B’ button of the relay unit, so it can be woken up and added to the system.

    setup IMG_2272

    After inspecting & testing the new wiring, the Boiler’s power circuit was switched back on. Further testing was completed & the operation of the RCD serving this circuit was confirmed.

    In the Fibaro System, a new device was added by the system entering ‘Learning/ListeningMode’ and the ‘B’ button on the Dual Relay carefully toggled 3 times.

    Hallway Screen Shot 2016-07-13 at 11.52.03

    The 2 switches were then configured into the system & added to the ‘Hallway’ Room as the Central Heating will be managed & controlled there. As can be seen, either the Central Heating and/or the Hot Water can be manually turned on/off from this panel and from a smart-phone or tablet now.

    Screen Shot 2016-07-12 at 16.30.25 linked device Screen Shot 2016-07-13 at 12.11.09

    Using the Heating Panel, a house temperature profile can be created. The Hallway thermometer is used as the controlling thermostat, via Linking the Hall Thermometer to the Central Heating (switch/relay). Alternatively multiple thermometers could be combined and the worse-case temperature, used as the controlling input.

    hot water Screen Shot 2016-07-13 at 12.06.59

    For the hot water, a simple schedule has been setup to switch on the boiler, to heat the hot water, in the morning & evenings. All aspects of the control and management of the house’s hot water & central heating can now be managed remotely by smart-phone & tablet.

    iPhone IMG_2275 iPad IMG_0060

    The remote-control of the system allows for the following:

    • Turning off the hot water & heating when away from the home, for extended periods of time, such as holidays.
    • Tuning the hot water & heating back on, when back in the country, such as in the arrivals hall of an airport.

    Future Enhancements to the System

    • Turn off the boiler in the event of Fire/Carbon monoxide detection/Flooding or other disasters.
    • Adding Nest style smart energy management.
    • Turn off the central heating if doors and/or windows are opened.