Evohome Thermostats randomly setting to 5 Degrees C

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • prowl
    Automated Home Lurker
    • Feb 2017
    • 2

    Evohome Thermostats randomly setting to 5 Degrees C

    So I have a new evohome and a few of thermostats randomly set to 5 Degrees C

    The connection seems good and it's the same 2/3 thermostats that do this.

    Any idea?

    Thanks
  • dty
    Automated Home Ninja
    • Aug 2016
    • 489

    #2
    Two of mine (in the same room) did this about an hour ago. I've never seen it before.

    The fact that they're in the same room suggests that it was some kind of controller initiated thing. However, the controller didn't think it was an override (i.e. there was no "cancel override" option).

    Comment

    • prowl
      Automated Home Lurker
      • Feb 2017
      • 2

      #3
      Originally posted by dty View Post
      Two of mine (in the same room) did this about an hour ago. I've never seen it before.

      The fact that they're in the same room suggests that it was some kind of controller initiated thing. However, the controller didn't think it was an override (i.e. there was no "cancel override" option).
      Interesting - did you notice it on the app or the controller first? I wondered if it was an app thing?

      No override cancel for me either.

      Mine are in separate zones. Only ones on each?

      Does Evohome auto update firmware ore anything? Wonder if that's the case?

      Comment

      • dty
        Automated Home Ninja
        • Aug 2016
        • 489

        #4
        I was using the app to tweak some schedules at the time. Perhaps related?

        The two thermostats that changed are the only ones in this room. So... all the stats in one zone.

        Evohome does have over-the-air firmware updates if you have the latest wifi controller, but AFAIK there has only been one update since it was launched.

        Comment

        • Bazinga
          Automated Home Jr Member
          • Feb 2015
          • 22

          #5
          Is this the Open Window feature kicking in? The radiators' HR92 are sensing a rapid temperature decrease and changing the set point to 5C for 30 minutes. The Open Window function can be turned off in the relevant HR92's menu with Option 3 (Off, *30 mins, 60 mins, 90 mins)
          I've also noticed this behaviour if you change the Temperature Offset in the HR92 menu (Option 8). Ideally, I would have coded the HR92 to ignore Open Window temperature drops for say 5 mins after an adjustment to Option 8 Temperature Offset, but that doesn't appear to be the case.

          Comment

          • dty
            Automated Home Ninja
            • Aug 2016
            • 489

            #6
            Not in my case. Both stats were in a 21C room and there was no open window indicator on them or on the controller.

            Comment

            • Bazinga
              Automated Home Jr Member
              • Feb 2015
              • 22

              #7
              There is no indication of Open Window on the HR92. I'm not certain that there isn't an indication on the Wi-Fi Controller, but I don't recall seeing one whenever this has occurred. The only sign to me is when the Set Point is changed to 5C. If the set point changes back from 5C to (for example) 21C after 30 minutes (or however many minutes are set in Option 3 for that HR92) then that would confirm it. If the set point doesn't change, then it's down to something else. I have only seen a 5C change due to this. When my HR92 behave weirdly, they have defaulted to a 20C set point.

              Comment

              • DBMandrake
                Automated Home Legend
                • Sep 2014
                • 2361

                #8
                Originally posted by Bazinga View Post
                I've also noticed this behaviour if you change the Temperature Offset in the HR92 menu (Option 8). Ideally, I would have coded the HR92 to ignore Open Window temperature drops for say 5 mins after an adjustment to Option 8 Temperature Offset, but that doesn't appear to be the case.
                Yep, I had noticed this crazy oversight in the open window algorithm as well - clearly the open window algorithm monitors for sudden drops in the calibrated temperature not the raw temperature, so when you reduce the calibrate setting it triggers open window detection! Kind of a silly bug that.

                Originally posted by Bazinga View Post
                There is no indication of Open Window on the HR92. I'm not certain that there isn't an indication on the Wi-Fi Controller, but I don't recall seeing one whenever this has occurred. The only sign to me is when the Set Point is changed to 5C. If the set point changes back from 5C to (for example) 21C after 30 minutes (or however many minutes are set in Option 3 for that HR92) then that would confirm it. If the set point doesn't change, then it's down to something else. I have only seen a 5C change due to this. When my HR92 behave weirdly, they have defaulted to a 20C set point.
                Actually on an HR92 if you press the button it will say WINDOW at the bottom of the display instead of the zone name. And the Wi-Fi model controller definitely displays the window icon on the screen - I've seen it loads of times as it tends to trigger in my kitchen when the back door is open in the cold mornings to get the car ready. It certainly works!

                The phone apps won't show it though, they just show a 5 degree set point, which can be confusing until you realise what has happened.

                BTW if your HR92's are reverting to a 20 degree set point randomly (and this is not in your schedule) I'd check the battery contacts - they may be spontaneously rebooting due to a poor battery connection, as 20 degrees is the default set point of an HR92 after the batteries are inserted. I've had it happen to me on two HR92's now! I had to tighten the spring loaded contacts a bit.
                Last edited by DBMandrake; 10 February 2017, 01:03 PM.

                Comment

                • dty
                  Automated Home Ninja
                  • Aug 2016
                  • 489

                  #9
                  Originally posted by Bazinga View Post
                  There is no indication of Open Window on the HR92. I'm not certain that there isn't an indication on the Wi-Fi Controller, but I don't recall seeing one whenever this has occurred. The only sign to me is when the Set Point is changed to 5C. If the set point changes back from 5C to (for example) 21C after 30 minutes (or however many minutes are set in Option 3 for that HR92) then that would confirm it. If the set point doesn't change, then it's down to something else. I have only seen a 5C change due to this. When my HR92 behave weirdly, they have defaulted to a 20C set point.
                  As DBMandrake has pointed out, HR92s (at least mine!) do have an indication of open window mode, as does the WiFi controller. I'm 99% certain it wasn't window mode kicking in.

                  Comment

                  • Rameses
                    Industry Expert
                    • Nov 2014
                    • 446

                    #10
                    You can change the 'sensitivity' of the HR92 inside the deep settings.
                    getconnected.honeywell.com | I work for Honeywell. Any posts I make are purely to help if I can. Any personal views expressed are my own

                    Comment

                    Working...
                    X