Hot Water Control


I have spoken to tado chat, and I am still unsure how to proceed. I am happy to contact a professional installer if needed.

Here's the basic setup I have a tado wired thermostat and 6 TRVs upstairs this is working fine, downstairs I have underfloor zoned heating (and I am going to leave this alone).

I have hot water controlled by a Honeywell ST9100C, I'd like to replace this and bring it into the Tado ecosystem. Chat have suggested an add-on receiver, however, this seems to suggest it will use the tado wired smart thermostat to call for heat, in my situation this wouldn't work as one of the radiators upstairs doesn't have a TRV so I wouldn't want this to come on when the hot water does. Have I miss understood how the add-on works? The add-on receiver seems to support heating and hot water, is it ok just to use it for hot water?




  • GrilledCheese2
    GrilledCheese2 ✭✭✭
    edited May 9

    Worst case scenario is you have a new wireless thermostat that does nothing, because the heating channel in the wireless receiver will not be connected to anything. Plus you'll have a tile/room in the app that is redundant. The existing thermostat and TRVs work as before.

    The Tado documentation explicitly states that the wireless receiver is suitable for heating, or heating and hot water. No reference to HW only, but their documentation is quite patchy. Unless someone here has experience of using the receiver as a single channel device you'll probably need to contact customer support again. The question you need to ask is whether you can use the receiver for 'hot water only' and 'turn off' the redundant new wireless thermostat.

  • some of the below might be relevant

    Our system is 2 separate heating zones(zone 1 - ground floor, zone 2 - 1st and second floor bedrooms) each zone having a wired Honeywell thermostat and a wired Honeywell ST9100C timer nest to the boiler

    We were told we needed the wireless receiver to replace replace the Honeywell ST9100C timer to effectively control the hot water(i.e. on or off) and wired thermostats to replace existing ones

    I used an electrician( who was convinced the timer was controlling the thermostats) and he set the wireless receiver up choosing the control the heating option(turns out he only had installed Nest before) have since found out from the plumber that it should be set up to control the hot water

    ***We now have the situation where the heating has to be on, on one of the thermostats, for the hot water to come on(yes each zone has a radiator with no TRV)***

    Did contact support and asked how do I remove a device(wireless receiver) using the android app so that I could try and reinstall it choosing the Hot Water option, basically I got a rubbish reply from support indicating they didn't understand the question or couldn't be bothered to read it properly

    looking at the web based login it does appear to give me an option to remove a device, so intend trying this and then reinstall the wireless receiver selecting the control Hot Water option

    hopefully if if the electrician hasn't mucked the wiring up it should work

  • For the effort involved for a little gain. I think I might just leave it outside the ecosystem for now!