Hot water control

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • Me-again
    Automated Home Jr Member
    • Oct 2020
    • 25

    #16
    Well thats very interesting to know, just wondering how that may affect my temp install. The hot water set up i have applies all year round, comes on once for 5-1/2 hours per day at the same switching on/off time. Come summer with the water being warmer when entering the immersion tank and remaining hot for longer there may be less calls for the boiler to fire up during the on period. Hopefully it will carry on running fault free as it has been.

    Regarding the controller and the CS92 and you having the CS92 powered from the mains that was never going to cure your problem as the CS92 is designed to run from batteries and the software to control it was written around that parameter and i am thinking making the batteries last as long as possible was high up the to do list. If only they had designed it to run from batteries or a mains power supply option that might have been problem solved.

    Comment

    • bruce_miranda
      Automated Home Legend
      • Jul 2014
      • 2307

      #17
      A mains powered CS92 option would have been ideal especially as the likelihood of there being a power source in the vicinity of the HW tank is quite high. Nevertheless, the issue isn't with the CS92 or it's batteries etc. It's just that because it is battery operated it is designed to only transmit when absolutely necessary and it's this infrequent message that the controller misses.

      Comment

      • Me-again
        Automated Home Jr Member
        • Oct 2020
        • 25

        #18
        As I said ( i am thinking making the batteries last as long as possible was high up the to do list). With people writing different software for evohome on here surely someone can find and implement a cure for the problems your having.

        Comment

        • bruce_miranda
          Automated Home Legend
          • Jul 2014
          • 2307

          #19
          I think the proper solution is not software only but needs a different hardware platform. But you are right, the SSM with evofw3 is an ideal platform to extend to add a temperature sensor to that can behave like the CS92. It will be mains powered, so can send out a temperature reading as frequently as required, rather than use the current CS92 algorithm where temperature readings are only sent when big temperature deltas are detected or its getting closer to the HW set point.

          Comment

          • Me-again
            Automated Home Jr Member
            • Oct 2020
            • 25

            #20
            That looks interesting and promising. Its the first i have heard about it, what is SSM. Is there a web page for it.

            Comment

            • CT1
              Automated Home Guru
              • Apr 2016
              • 189

              #22
              I had fully agreed that batteries had nothing to do with the comms problems, which I had quite regularly even with fresh batteries. However when I changed the batteries a few months ago, I took the opportunity to ensure both the unit and battery terminals were spotlessly clean. Since then I have had zero coms faults. This may just be a coincidence, but it could also be an indication that the batteries may contribute to the message being missed by the controller, e.g. if the signal level is slightly lower? I have no way to test this hypothesis. It is also worth noting that my hot water use is always low and infrequent because much of my requirement is covered by solar thermal and PV.

              Comment

              • bruce_miranda
                Automated Home Legend
                • Jul 2014
                • 2307

                #23
                The frequency of the comms failure messages is inversely proportionate to the numbers of messages the CS92 sends the controller. Changing, repositioning the batteries etc, just forces the CS92 to transmit and that helps re-establish the comms. Also the message is misleading, its not a genuine loss of comms, its the controller saying that I haven't heard the CS92 in a while. And the problem is that the controller just missed the last message the CS92 sent.

                Comment

                • CT1
                  Automated Home Guru
                  • Apr 2016
                  • 189

                  #24
                  Most of my water heating is done by sola with the EvoHome HW not used for several days at times, so presumably, the message rate is low. This would explain why I have traditionally had several loss of comms messages. There has been no change in my usage, the only thing to have changed is meticulous cleaning of the battery terminals and contacts. It has now been months without a comms fault. Could be a coincidence and I may get several comms faults next month, but the longer I go without a comms fault, the less I am inclined to believe it is not related. I am sure you are correct about the missed messages, but I am beginning to believe that batteries could be a contributing factor.

                  The reason I cleaned the contacts in the first place, was reading about another very low power application where the very low current was insufficient to “wet” the battery contacts. EvoHome’s use of very low power (and weak terminal tension) looked to make it a candidate for this problem, hence I now make a point of cleaning both batteries and contacts, so far so good.

                  Comment

                  • bruce_miranda
                    Automated Home Legend
                    • Jul 2014
                    • 2307

                    #25
                    My CS92 does not use batteries any more. And yet it will show a comms failure every so often.
                    And because I have a log of absolutely every Evohome RF message, it is quite easy for me to go and have a look and see what is happening. And each time it shows that the CS92 has actually spoken. It's the controller that just goes temporarily deaf and misses that infrequent CS92 message, which is enough for a comms fault to be raised.
                    But now I no longer care about those errors because I know they will just clear by themselves.

                    Comment

                    • Me-again
                      Automated Home Jr Member
                      • Oct 2020
                      • 25

                      #26
                      Had my first problems with the system, hot water set to 60c differential is +/- 6c and noticed H/W was showing at 71c on the controller and the boiler was still running so controller still calling for more heat from boiler. This is the second time i have noticed the controller showing H/W at 71c I didn't check if boiler was still running the first time though. What causes this problem.

                      Comment

                      • bruce_miranda
                        Automated Home Legend
                        • Jul 2014
                        • 2307

                        #27
                        What is the HW Over run set to? Also when you saw the HW temp go beyond the set point, what was the actual Heat Demand for the HW in the settings menu

                        Comment

                        • Me-again
                          Automated Home Jr Member
                          • Oct 2020
                          • 25

                          #28
                          The H/W over run is set to zero and i didnt think to check the heat demand, will do that if it happens again.

                          Comment

                          Working...
                          X