honeywell evohome - is it doable setup

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  • phier
    Automated Home Jr Member
    • Oct 2019
    • 18

    honeywell evohome - is it doable setup

    Hello,

    I am not able to find any specialist / official consultant of EvoHome (czech republic). In case I tried... they simply don't care about customers with few rooms and are not willing to provide any consultancy / installation. I am bit desperate.

    I am wondering if EvoHome might work under setup/condition I will describe in more detail. I own my electric boiler http://www.augur-kovo.cz/Electrother...ctric-boiler-b which can be powered on/off for about 20 hours during the day, there are 4x1hours intervals while High Signal is not there and boiler cant be powered on. I have 3 separate rooms (each has to be a single zone) where I want to control the temperature independently. I was thinking to install rele BRD91 into my electric boiler, setup 3 zones (each room = zone), each room will have 2 Evo valves on the radiators. The system will be controlled by evohome control unit. Is that right case for the evohome? Is it possible to setup/ install in such a setup?

    I tried eq-3 MAX system without any success... It seems that its meant for a central heating system without electric boiler as there is no chance to power on/off boiler as per zone.

    I was also wondering if there is any update of Evohome or if they plan to release a new/upgraded system, looks like evohome is a bit old stuff.


    Thank you!
    Last edited by phier; 3 November 2019, 01:17 PM.
  • phier
    Automated Home Jr Member
    • Oct 2019
    • 18

    #2
    hello, anyone? thank you so much.

    Comment

    • phier
      Automated Home Jr Member
      • Oct 2019
      • 18

      #3
      By HDO I meant ripple control system. Based on this page https://getconnected.honeywellhome.c...i-Brochure.pdf it seams evohome is not meant for setup with electric controlled boilers.

      evohome is suitable for any home with a hydronic (wet) central heating system.


      As I mentioned I have 6 intervals of 40minutes each while electric boiler cant operate. Evohome can't split daily program on more then 6 intervals with different tempreature... Sad fact. Totally unusable system.

      Comment

      • DanD
        Automated Home Ninja
        • Feb 2016
        • 250

        #4
        Yes, I think you've come to the correct conclusion. Unfortunately, Evohome isn't designed to control the boiler to the extent that you need. It can provide separate heating and hot water control signals to the boiler, but it's not designed to actually control the power to your electric boiler.

        It's also not possible to program the Evohome controller to tell it that the boiler is not to be used during certain times.

        Comment

        • phier
          Automated Home Jr Member
          • Oct 2019
          • 18

          #5
          Originally posted by DanD View Post
          Yes, I think you've come to the correct conclusion. Unfortunately, Evohome isn't designed to control the boiler to the extent that you need. It can provide separate heating and hot water control signals to the boiler, but it's not designed to actually control the power to your electric boiler.

          It's also not possible to program the Evohome controller to tell it that the boiler is not to be used during certain times.

          Hi, that's more than sad story. What is relé brd91 good for?and why resellers say it's fine for my use case?

          Is there any other system that I can use for my setup? Is danfoss fine for it or has same issues for such a setup as evohome?

          Frankly I am more then desperate. Thank you!

          Comment

          • DanD
            Automated Home Ninja
            • Feb 2016
            • 250

            #6
            Hi,

            I've self-installed my Evohome system with a gas boiler, so I'm not an expert. The BDR91s are used as switch controls for devices like valves and to provide boiler control (connected to its thermostat) and I think the maximum current they can control is 5 amps. You could use an Evohome system to provide part of your heating control solution, but it would be quite expensive and not provide the programming control you need. The Evohome controller doesn't have any features to tell it that a boiler can't supply heat during specific times and I don't know of a controller which can. It does have the flexibility of up to 6 setpoints per zone per day and you could set 4 of these to the minimum temperature (5deg) for each of the periods, but this wouldn't leave much remaining flexibility for controlling the room temperatures.

            I'm really not sure what benefits the Evohome system has that would help solve your problem.

            Dan

            Comment

            • phier
              Automated Home Jr Member
              • Oct 2019
              • 18

              #7
              Hi,

              not really, you can also control electric boiler with that BDR91 - to power it on/off.

              What do you mean by part of the solution and why quite expensive? not provide the programming control I need? Wh? Sorry, too many questions.

              Evohome has no features for it but i can programm it by daily program ie during the periods there is no power do not heat/supply heat. I thought that there is a chance to increase number of setpoints per zone per day.


              The benefit I was looking for to be able remotely to control temperature and increase/decrease it via controller so do not need to touch thermo heads manually in each room.

              I also set per zone to use temperature from a controller but it even is broken or I do not understand why other thermometers around Evo control unit show, for example, 23C but Evo control unit only 21.5 or so... seams that accuracy is miserable to even measure room temperature...

              Happy for any advice... maybe I am not setting it correctly.

              Comment

              • gordonb3
                Automated Home Ninja
                • Dec 2016
                • 273

                #8
                Is this similar to what is called heizungsstrom in Germany? From what I understand the boiler in this setup is supposed to act like a hot water "battery" that should not draw any power during peak hours. As such I think you should regard the boiler as an external source of hot water, much like city block heating. Effectively you let the BDR unit control the switch that your old thermostat used to control, which in a system like yours will be either a valve if the system is pressurized or a pump when not.

                Comment

                • phier
                  Automated Home Jr Member
                  • Oct 2019
                  • 18

                  #9
                  hi, not sure what heizungsstrom is but yes ... its central heating electro boiler which exchanges power to hot water which is then circulating and moved to radiators.

                  During peak hours ... means six times during the day for 40min you cant power it on.

                  I dont think evohome will be able to operate system like that... even i am so pissed of its control unit which shows for example now 22C and two other thermometers shows something different ... https://photos.app.goo.gl/hHSrEkpjxDvnBiFN7

                  It doesnt shows on display temp on at least one decimal point ... and costs almost 200euro...

                  Comment

                  • gordonb3
                    Automated Home Ninja
                    • Dec 2016
                    • 273

                    #10
                    Yes, that does sound similar.

                    So here's the thing: I don't think you should try let Evohome control whether or not the boiler goes into a heating cycle for the simple reason that Evohome cannot predict any manual input you might perform in the next 1-40 minutes. You use Evohome in the secundary part of the system to control if, where and when the heat is deployed to any of the available radiators (or other heating devices) and thus how much heat is drawn from the boiler, which in turn determines whether or not it's internal sensor will cause it to switch on at the next available slot.

                    As for temperature display: that is an often heard nuisance. Evohome is known to round down when there is no heat demand and round up when there is. The actual temperature can be queried through the web portal though (if you have a Wifi enabled controller or RFG100 to accompany it).

                    Comment

                    • phier
                      Automated Home Jr Member
                      • Oct 2019
                      • 18

                      #11
                      Hello,
                      I know exact times when the power is off for these 40minutes. That's why i wanted to program it to set temp for example on 0C during these 40min intervals. There are I think 6x40min intervals during the day.

                      What internal sesnsor do you mean? I am bit confused, you mean BDR91?


                      Yeah I linked it via mobile app, so now the evo controller shows 21.5C , my two other thermometers 22.5C and app current 21.5C and target 21.5C ... that's odd.


                      thanks

                      Comment

                      • DanD
                        Automated Home Ninja
                        • Feb 2016
                        • 250

                        #12
                        Oh, I didn't realise that you already had some of the Evohome devices!

                        I think I may have misunderstood exactly what you wanted the Evohome system to do.

                        Here's what the Evohome system should be able to do for you:
                        • Allow each of the 3 zones within your home to operate their own programs with 6 changes in temperature setpoints per zone, per day.
                        • You mention putting 2 valves in each of your zones and I assume you mean adding HR92s TRVs to your radiators which function as both a temperature sensor and control the variable flow valve. These HR92s also allow you to change the room temperature directly by turning their control wheel and this temporarily overrides the program temperature. This will cause the BDR91 to send a signal to the boiler to heat, if it currently not heating.
                        • The Evohome system will learn how quickly your rooms heat up and cool down and try to optimise the use of your boiler to efficiently heat your zones. 'Optimum Start' and 'Optimum Stop' options also help to maintain the room temperatures by either heating the zone early to ensure that it quickly achieves a program increase in setpoint target, or switching off the heat to a zone early to efficiently achieve a program decrease in setpoint.

                        Here's what Evohome is unable to do:
                        • It isn't possible to program the controller to tell it that the boiler will not respond to requests for heat during certain times during the day. The BDR91 will still send a signal to the boiler for heat even if the boiler is unable to provide heat during the 40min intervals.


                        Apart from the limitation above, I think Evohome should be able to efficiently control your heating. I don't use the temperature sensor within the controller and each of my HR92s to measure the temperature of each zone (I use all 12 zones with 16 HR92s in my setup).


                        Dan

                        Comment

                        • phier
                          Automated Home Jr Member
                          • Oct 2019
                          • 18

                          #13
                          Hi Dan,


                          I am not sure, during these 40min intervals... while demand on the heat will come to the controller ... it will just make it disoriented ... I assume ... that's why I was asking to setup whats apparently is not possible.



                          Yes, I was talking about HR92 valves. I thought valves are not showing current temp in the room. But it seems that control unit doesnt come with that much precise calibrated thermometer... right now it shows 22C but other 2 meters shows 22.7 and 22.4.

                          I am bit skeptic ... about whole system and thinking if danfoss would be better solution? if any.

                          Comment

                          • DanD
                            Automated Home Ninja
                            • Feb 2016
                            • 250

                            #14
                            I think the controller will work OK and the 40min periods won't cause it problems. It's a shame that the Evohome 6 setpoint daily limit isn't enough for your setup. I find the Evohome system works well and keeps my home at a comfortable temperature. You might need to try increasing the setpoint before the first 40min period if the temperature drops too far, but it should provide good control.

                            Comment

                            • phier
                              Automated Home Jr Member
                              • Oct 2019
                              • 18

                              #15
                              well shame... there are these 40min intervals...

                              what's the point to increase before first 40min period... can't see it....


                              also wondering why temperature shown on control unit differs from other thermometers...

                              Comment

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