New evohome FW - update WiFi 02.00.17.00 and Application 02.00.17.03

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  • HenGus
    Automated Home Legend
    • May 2014
    • 1001

    #76
    So what do the percentages actually mean? I have seen 6% on one of my 12 zones and 100% on Opentherm?

    Comment

    • DBMandrake
      Automated Home Legend
      • Sep 2014
      • 2361

      #77
      Originally posted by HenGus View Post
      So what do the percentages actually mean? I have seen 6% on one of my 12 zones and 100% on Opentherm?
      Try comparing them with the Valve position (option 10) on the HR92 and see if they are a 1 to 1 match ?

      The "heat demand" that the HR92 sends to the controller we've previously confirmed is exactly the same as the valve position reported in option 10 on the HR92, however it's possible that it won't be displayed like this because a 20% valve position (and thus heat demand) may not be sufficient to actually open the valve enough for water to flow, so it would be misleading for it to say that the zone was demanding 20% heat when the valve wasn't even flowing.

      Calibration of the HR92's typically seems to result in a valve pin movement of about 30-40% being required before water starts to flow, and the controller probably knows this and "fudges" the heat demand sent to the BDR91 to account for this.

      The way to tell this would be to turn all but one zone down to 5 degrees, and set one zone to 0.5 degrees below the current temperature to see if the heat demand of that one zone equals the heat demand sent to the BDR91 or not.

      Something I will certainly try when I get home... it will be interesting to try to figure out how the individual zone heat demands translate to an overall heat demand for the boiler. I suspect there is a bit more than just max() of all zones involved at the bottom end...
      Last edited by DBMandrake; 20 December 2017, 09:54 PM.

      Comment

      • paulockenden
        Automated Home Legend
        • Apr 2015
        • 1719

        #78
        I have S Plan currently wired the old fashioned way with no boiler relay.

        My system summary shows the controller output demand for the hot water, but not for the heating. So I only see inputs, not the output from the controller.

        I notice someone said that OT values are shown, so I expect a boiler relay probably is too. Shame the CH percentage isn’t shown though - feedback I passed back to Ramses earlier in the beta cycle.

        Comment

        • DBMandrake
          Automated Home Legend
          • Sep 2014
          • 2361

          #79
          Originally posted by paulockenden View Post
          I have S Plan currently wired the old fashioned way with no boiler relay.

          My system summary shows the controller output demand for the hot water, but not for the heating. So I only see inputs, not the output from the controller.

          I notice someone said that OT values are shown, so I expect a boiler relay probably is too. Shame the CH percentage isn’t shown though - feedback I passed back to Ramses earlier in the beta cycle.
          Odd - sounds like a bug. Don't you have a spare BDR91 ? Bind it as a dummy boiler control relay....

          I have a 3x BDR91 system so hopefully I'll be able to see the boiler demand.

          Comment

          • IM35461
            Automated Home Sr Member
            • Jan 2012
            • 69

            #80
            My system summary list heat demand list seems to be in error.
            Both the bedrooms are set to warm up from 21:30 and been up and checked and they are both now getting hot but according to the list (which alas does not seem to auto update) says 0% for one bedroom.

            2017-12-20 21.40.30.jpg

            Boiler on all the time which I guess represents the 100% value for always on

            Comment

            • mtmcgavock
              Automated Home Legend
              • Mar 2017
              • 507

              #81
              I've got the boiler relay bound, with a 19% demand from a HR92 the boiler relay is showing 100% demand, along with the Stored Hot water showing a 100% demand (Due to the 2 port valve set up in the settings).

              Comment

              • mtmcgavock
                Automated Home Legend
                • Mar 2017
                • 507

                #82
                Originally posted by IM35461 View Post
                My system summary list heat demand list seems to be in error.
                Both the bedrooms are set to warm up from 21:30 and been up and checked and they are both now getting hot but according to the list (which alas does not seem to auto update) says 0% for one bedroom.

                [ATTACH=CONFIG]1156[/ATTACH]

                Boiler on all the time which I guess represents the 100% value for always on
                Isn't it a case where the radiator is hot but Evohome has shut the HR92 down?

                Comment

                • IM35461
                  Automated Home Sr Member
                  • Jan 2012
                  • 69

                  #83
                  Originally posted by mtmcgavock View Post
                  Isn't it a case where the radiator is hot but Evohome has shut the HR92 down?
                  The heating only comes on at 21:30 and both rooms were cold.

                  20mins later, it now reads 100% for both bedrooms and the list does auto update but not sure how often.

                  EDIT: One bedroom has now gone down to 60% without having to touch the unit screen

                  2017-12-20 21.59.04.jpg
                  Last edited by IM35461; 20 December 2017, 11:01 PM.

                  Comment

                  • dty
                    Automated Home Ninja
                    • Aug 2016
                    • 489

                    #84
                    Hmm... the demand values seem to be a little... vague.

                    evohome-demand.jpgIMG_2300.jpgIMG_2301.jpgIMG_2302.jpg

                    The first image is the actual current demand (broken down by individual radiator in multi-radiator zones). The other three are the demands reported in Evohome.

                    Something's amiss...

                    EDIT: I have no idea why these images are upside down, sorry!
                    Last edited by dty; 20 December 2017, 11:22 PM.

                    Comment

                    • DBMandrake
                      Automated Home Legend
                      • Sep 2014
                      • 2361

                      #85
                      Originally posted by mtmcgavock View Post
                      I've got the boiler relay bound, with a 19% demand from a HR92 the boiler relay is showing 100% demand, along with the Stored Hot water showing a 100% demand (Due to the 2 port valve set up in the settings).
                      If your stored hot water is in a reheat cycle (which I assume it must be if it is showing a 100% demand for the hot water relay) then you will indeed see 100% demand on the boiler relay as well. That's normal. In these conditions only the heating zone valve relay will TPI modulate until the stored hot water demand has been satisfied. Then the boiler relay demand should track the heating zone valve demand and TPI modulate together in time with each other.
                      Last edited by DBMandrake; 20 December 2017, 11:23 PM.

                      Comment

                      • DBMandrake
                        Automated Home Legend
                        • Sep 2014
                        • 2361

                        #86
                        Originally posted by IM35461 View Post
                        The heating only comes on at 21:30 and both rooms were cold.

                        20mins later, it now reads 100% for both bedrooms and the list does auto update but not sure how often.

                        EDIT: One bedroom has now gone down to 60% without having to touch the unit screen

                        [ATTACH=CONFIG]1157[/ATTACH]
                        Easy way to tell how frequently the heat demand screen updates when left alone - make a major change to the set point of a zone by turning the dial on an HR92 from well below to well above the current temperature. This will send an updated heat demand a couple of seconds after the motor in the HR92 has finished turning.

                        Comment

                        • mtmcgavock
                          Automated Home Legend
                          • Mar 2017
                          • 507

                          #87
                          I wasn’t really stating that anything was wrong with them figures.... but you’ve brought up a question. Surely the boiler relay will only ever show a 100% demand or 0% as the output is only a on or off. It can’t modulate in between. I haven’t used any external monitoring before so I’m unsure how this is shown in any other reporting.

                          Comment

                          • paulockenden
                            Automated Home Legend
                            • Apr 2015
                            • 1719

                            #88
                            From my observations I think the values update as soon as new data is received from an HR92 or other device. It isn’t on a timed update schedule.

                            Comment

                            • dty
                              Automated Home Ninja
                              • Aug 2016
                              • 489

                              #89
                              Originally posted by mtmcgavock View Post
                              I wasn’t really stating that anything was wrong with them figures.... but you’ve brought up a question. Surely the boiler relay will only ever show a 100% demand or 0% as the output is only a on or off. It can’t modulate in between. I haven’t used any external monitoring before so I’m unsure how this is shown in any other reporting.
                              If the display matches the radio data, it will show all interim values. The total load (say, 40%) is sent to the relay and it is responsible for turning itself on and off on a 40% duty cycle. The controller doesn't tell the relay to turn on and off each cycle.

                              Comment

                              • DBMandrake
                                Automated Home Legend
                                • Sep 2014
                                • 2361

                                #90
                                Originally posted by dty View Post
                                Hmm... the demand values seem to be a little... vague.

                                [ATTACH=CONFIG]1158[/ATTACH][ATTACH=CONFIG]1159[/ATTACH][ATTACH=CONFIG]1160[/ATTACH][ATTACH=CONFIG]1161[/ATTACH]

                                The first image is the actual current demand (broken down by individual radiator in multi-radiator zones). The other three are the demands reported in Evohome.

                                Something's amiss...

                                EDIT: I have no idea why these images are upside down, sorry!
                                I'm assuming your first picture (very hard to read) is a report from Domoticz with an HGI80 or equivalent ?

                                If so your screenshots would tend to confirm the suspicion I posted about earlier - the percentage display on the controller is probably not the "raw" heat demand figure sent from the HR92, which as discussed earlier is simply the valve pin position travel in 0-100%. (a 0-200 integer in the protocol)

                                You'll notice that all of the zones which say 0% on the controller but above 0% on your Domoticz (?) dump are well below 30% as a raw figure. This means that although the valve pin on these is not fully pressed down, I'll almost guarantee none of those radiators are flowing any water, as most valves won't start flowing until an indicated 30-40% pin travel on the HR92.

                                So lets say an HR92 has its pin 25% up, at this point there is still no water flowing through the radiator, but it sends this raw 25% value to the controller. The controller is smart enough to know that 25% won't be enough for water to flow so this 25% does not contribute to actual heat demand sent to the boiler so is truncated to 0%.

                                So the percentage value shown in the controller for each zone is not the raw pin position sent by the HR92's, but rather the contribution from that zone towards sending an actual heat demand to the boiler, which won't happen until some threshold value from the HR92 is reached, probably around 40%. Make sense ?

                                If this is how it's working (and I'll know soon enough when I get home and start testing mine) then it's working as intended, and is giving an accurate depiction of how much each zone is contributing towards firing the boiler, which is what we want to know.

                                What remains to be seen is whether the same threshold is always used for all zones or whether it adapts the threshold to the characteristics of each radiator valve individually, and what the mapping between raw values and zone heat demand contribution to the boiler is. But that's fairly easy to work out with a bit of testing and logging.
                                Last edited by DBMandrake; 20 December 2017, 11:43 PM.

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