Evohome firmware 02.00.19.31 Beta Trial - Exclusive for Automated Home Members

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  • AlexP
    Automated Home Jr Member
    • Feb 2016
    • 10

    #91
    I’m seeing a similar thing in one room only. Set point gets set to 35 during heat up then resets once the set point time is reached. Doesn’t happen every time but has at least 3 times now. Have reset the hr92 in the offending room to see if that helps... will report back.

    Comment

    • mtmcgavock
      Automated Home Legend
      • Mar 2017
      • 507

      #92
      Originally posted by Andy the Minion View Post
      In a previous life I came from the boiler industry and have been used to setting the pump to run constantly in opentherm or otc systems. The HR92 stay open when the boiler is off and my logic is this allows the heat that may have be left standing in a pipe run to be distributed evenly within the house and the water comes down to a nice steady return temperature ready for the next burner on cycle. I have no actual evidence which is better mind, just a gut feeling.
      I would agree with you on this one, i've been thinking for a while to wire some timer into the MV for heating to hold it open after been energised - allowing for the heat to the rads rather than the bypass circuit. Unfortunately as I said my MV closes so that heat from the over run is wasted as such.

      Comment

      • Andy the Minion
        Automated Home Sr Member
        • Nov 2017
        • 86

        #93
        Originally posted by mtmcgavock View Post
        Don't think we've got any chance of getting that
        I'm definitely not arguing against this one, it's a very good idea. I have however seen blood drain from the faces of software engineers when they describe the effect on the state engine that is running Evo. I think it's a case of "You want to get where? Oh well you shouldn't start from here". Next gen, it's on the list.
        Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

        Comment

        • Andy the Minion
          Automated Home Sr Member
          • Nov 2017
          • 86

          #94
          Originally posted by paulockenden View Post
          Ideally the outside temp used would be a 'feels like' temperature, as that includes wind chill (which chills houses as much as it chills people). Much better than just using a normal 'weather station' type value.
          It is prepared for this, and some more.... cloud issues, grrrr
          Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

          Comment

          • Andy the Minion
            Automated Home Sr Member
            • Nov 2017
            • 86

            #95
            Originally posted by mtmcgavock View Post
            Yes but with OT theres a demand, so the pump is pumping somewhere - on a TPI cycle the BDR91 unlatches and closes the Heating MV and therefore it's just pumping round the bypass. So all the useable heat is just going round the bypass circuit.
            Yep true that overruled the HR92 is open statement, I'm not a big fan of on/off valves unless they are completely necessary (I know, sometimes they are)
            Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

            Comment

            • Andy the Minion
              Automated Home Sr Member
              • Nov 2017
              • 86

              #96
              Originally posted by Andy the Minion View Post
              Yep true that overruled the HR92 is open statement, I'm not a big fan of on/off valves unless they are completely necessary (I know, sometimes they are)
              Oh actually in tpi control there is still a demand just as in opentherm, the burner just happens to be off
              Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

              Comment

              • DBMandrake
                Automated Home Legend
                • Sep 2014
                • 2361

                #97
                Originally posted by Andy the Minion View Post
                In a previous life I came from the boiler industry and have been used to setting the pump to run constantly in opentherm or otc systems. The HR92 stay open when the boiler is off and my logic is this allows the heat that may have be left standing in a pipe run to be distributed evenly within the house and the water comes down to a nice steady return temperature ready for the next burner on cycle. I have no actual evidence which is better mind, just a gut feeling.
                This is exactly my thinking as well. If the pump keeps stopping every few minutes hot water sits losing heat in pipework without reaching the radiators, especially with a low TPI duty cycle where the one or two minutes on time might not even be enough for the slug of hot water to reach some radiators. Continous flow through the radiators while the boiler flame cycles on and off gives a more even distribution of heat around the system.

                It also helps prevent kettling in the boiler heat exchanger as it's not forcing the entire flow to go through the ABV every few minutes. (Removing the boilers heatsink in the process)

                However to make this work properly on a system like mine with a heating zone valve (and address the issue mtmcgavock raises about the heating zone valve closing) I have a nice little wiring hack for my heating zone valve that I've been using for the last couple of years:



                In short, if the hot water relay is on, (hot water reheat) the heating zone valve follows the on/off status of the heating relay.

                However when the hot water relay is off the heating zone valve will ignore the heating relay and stay on so long as the pump is running. (Even during overrun)

                This allows water to continue circulating continuously through radiators throughout the TPI cycle except when there is a hot water reheat in progress which might otherwise cause the radiators to go over temperature. When a hot water reheat is in progress the heating zone valve will follow normal TPI control to reduce heat transfer to the radiators.
                Last edited by DBMandrake; 3 April 2020, 07:36 PM.

                Comment

                • SteveP
                  Automated Home Guru
                  • Dec 2012
                  • 190

                  #98
                  Originally posted by Andy the Minion View Post
                  Steve, The others are commenting on the process of adding the service company for diagnostics, rather than requesting the firmware. The second is completely optional.
                  Thanks Andy I was just concerned that the selection may have an impact on parameters and be part of the remote install.

                  Comment

                  • bruce_miranda
                    Automated Home Legend
                    • Jul 2014
                    • 2307

                    #99
                    Years ago, @DBMandrake came up with the brilliant idea to have the CH Valve open with the pump, rather than be controlled by Evohome. Best mod I made. It allows the CH Valve to open and close and hence not seize but more importantly it circulates the heat through the loop in pump over run mode. it also takes care of boiler frost protection too. I love the idea, so simple and effective.

                    Comment

                    • SteveP
                      Automated Home Guru
                      • Dec 2012
                      • 190

                      Originally posted by Andy the Minion View Post
                      It is prepared for this, and some more.... cloud issues, grrrr
                      Andy - sounds intriguing, can you elucidate? is there more to this algorithm than just what the temperature reads on the controller?

                      Comment

                      • Andy the Minion
                        Automated Home Sr Member
                        • Nov 2017
                        • 86

                        Originally posted by SteveP View Post
                        Andy - sounds intriguing, can you elucidate? is there more to this algorithm than just what the temperature reads on the controller?
                        Well it was around Paul's comment on wind chill, i will be checking the office for bugs (Paul I'm looking at you ) We have another cunning plan that the device is prepared for but needs additional weather data .... and now we get into confidentiality issues and project planning so I will stop there.
                        Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

                        Comment

                        • mtmcgavock
                          Automated Home Legend
                          • Mar 2017
                          • 507

                          Originally posted by DBMandrake View Post
                          This is exactly my thinking as well. If the pump keeps stopping every few minutes hot water sits losing heat in pipework without reaching the radiators, especially with a low TPI duty cycle where the one or two minutes on time might not even be enough for the slug of hot water to reach some radiators. Continous flow through the radiators while the boiler flame cycles on and off gives a more even distribution of heat around the system.

                          It also helps prevent kettling in the boiler heat exchanger as it's not forcing the entire flow to go through the ABV every few minutes. (Removing the boilers heatsink in the process)

                          However to make this work properly on a system like mine with a heating zone valve (and address the issue mtmcgavock raises about the heating zone valve closing) I have a nice little wiring hack for my heating zone valve that I've been using for the last couple of years:



                          In short, if the hot water relay is on, (hot water reheat) the heating zone valve follows the on/off status of the heating relay.

                          However when the hot water relay is off the heating zone valve will ignore the heating relay and stay on so long as the pump is running. (Even during overrun)

                          This allows water to continue circulating continuously through radiators throughout the TPI cycle except when there is a hot water reheat in progress which might otherwise cause the radiators to go over temperature. When a hot water reheat is in progress the heating zone valve will follow normal TPI control to reduce heat transfer to the radiators.
                          Surely with this though in the summer you get heat into any rads with no HR92s?

                          It is something i'm going to have to implement though, i'm just getting a lot of wasted heat - my rad in my garage acts as a bypass so all the heat is going into there.

                          Comment

                          • paulockenden
                            Automated Home Legend
                            • Apr 2015
                            • 1719

                            Originally posted by Andy the Minion View Post
                            i will be checking the office for bugs (Paul I'm looking at you )
                            There's no monopoly on good ideas. Especially when they are so bleedin' obvious!

                            Comment

                            • DBMandrake
                              Automated Home Legend
                              • Sep 2014
                              • 2361

                              Originally posted by mtmcgavock View Post
                              Surely with this though in the summer you get heat into any rads with no HR92s?
                              I don't have any radiators without HR92's anymore, so not in my situation no.

                              You're right though - if you did have a bypass radiator then at the end of a hot water reheat cycle in summer a small amount of latent heat from the boiler heat exchanger would be dumped into that cold bypass radiator, however that's a good thing for the boiler, and it would barely be enough to make the radiator luke warm and would only occur once at the end of each hot water reheat cycle. (The heating zone valve would stay closed until the hot water zone valve closed and the boiler stopped firing - then it would open when there was only latent heat remaining)

                              When I did have a bypass radiator it barely warmed at all from the heat dump due to the relatively high thermal mass of the radiator vs boiler heat exchanger.

                              Now that I have all HR92 controlled radiators I rely on a one minute hot water overrun to allow latent heat to dissipate at the end of the hot water reheat cycle.

                              Comment

                              • Andy the Minion
                                Automated Home Sr Member
                                • Nov 2017
                                • 86

                                Originally posted by DBMandrake View Post
                                This is exactly my thinking as well. If the pump keeps stopping every few minutes hot water sits losing heat in pipework without reaching the radiators, especially with a low TPI duty cycle where the one or two minutes on time might not even be enough for the slug of hot water to reach some radiators. Continous flow through the radiators while the boiler flame cycles on and off gives a more even distribution of heat around the system.

                                It also helps prevent kettling in the boiler heat exchanger as it's not forcing the entire flow to go through the ABV every few minutes. (Removing the boilers heatsink in the process)

                                However to make this work properly on a system like mine with a heating zone valve (and address the issue mtmcgavock raises about the heating zone valve closing) I have a nice little wiring hack for my heating zone valve that I've been using for the last couple of years:



                                In short, if the hot water relay is on, (hot water reheat) the heating zone valve follows the on/off status of the heating relay.

                                However when the hot water relay is off the heating zone valve will ignore the heating relay and stay on so long as the pump is running. (Even during overrun)

                                This allows water to continue circulating continuously through radiators throughout the TPI cycle except when there is a hot water reheat in progress which might otherwise cause the radiators to go over temperature. When a hot water reheat is in progress the heating zone valve will follow normal TPI control to reduce heat transfer to the radiators.
                                Simon i replied to your pm but was told you broke your mailbox and need to clear some space
                                Resideo employee. Comments are personal, and likely to get a hard stare from Rameses

                                Comment

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