Evohome Hot water problems

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  • mtmcgavock
    Automated Home Legend
    • Mar 2017
    • 507

    #61
    Out of interest, have you tried rebooting the controller since the new batteries were fitted.

    Comment

    • DBMandrake
      Automated Home Legend
      • Sep 2014
      • 2361

      #62
      Originally posted by mtmcgavock View Post
      Out of interest, have you tried rebooting the controller since the new batteries were fitted.
      Yep, I have.

      Comment

      • mtmcgavock
        Automated Home Legend
        • Mar 2017
        • 507

        #63
        Laughably I've just had a Comms error after being away for 9 days. Turned system back on before we were heading home, glanced at the App to find our HW at 66oc! On return looking at the log there was a Comms error on the day of our return, specifically when I turned the system back on.

        Now all I can assume from this our HW was on 21oc before the system was turned back on - usually it never drops below 30oc as it's set to reheat when in use. No Comms issues since our return or any issues at all.

        Now my question would be - does your HW regularly drop below 30oc or so @DBMandrake?

        Comment

        • G4RHL
          Automated Home Legend
          • Jan 2015
          • 1580

          #64
          Originally posted by mtmcgavock View Post
          Laughably I've just had a Comms error after being away for 9 days. Turned system back on before we were heading home, glanced at the App to find our HW at 66oc! On return looking at the log there was a Comms error on the day of our return, specifically when I turned the system back on.

          Now all I can assume from this our HW was on 21oc before the system was turned back on - usually it never drops below 30oc as it's set to reheat when in use. No Comms issues since our return or any issues at all.

          Now my question would be - does your HW regularly drop below 30oc or so @DBMandrake?
          Mine does if it is used but then I only have Evohome switch it on for an hour in the morning and 30 minutes at night. Currently it is at 37c but will drop below that overnight. But then there is only Evohome controlling the hot water, no reheat setting. It does not usuall go below 30c but that is dependent on the house temperature.

          Comment

          • DBMandrake
            Automated Home Legend
            • Sep 2014
            • 2361

            #65
            Originally posted by mtmcgavock View Post
            Laughably I've just had a Comms error after being away for 9 days. Turned system back on before we were heading home, glanced at the App to find our HW at 66oc! On return looking at the log there was a Comms error on the day of our return, specifically when I turned the system back on.

            Now all I can assume from this our HW was on 21oc before the system was turned back on - usually it never drops below 30oc as it's set to reheat when in use. No Comms issues since our return or any issues at all.

            Now my question would be - does your HW regularly drop below 30oc or so @DBMandrake?
            Not while it is scheduled off, no. It typically drops from 54C down to about 42C when scheduled off overnight, and down to about 46C when scheduled off during a work day.

            Of course if I run a bath and use all the hot water the reading will drop into the 20's or 30's but then climb again as it reheats.

            In the background I've received my NanoCUL and started logging comms from the system with the help of the guys like DanD who are already doing this and digging deeper into the problem, and the situation with the CS92A is even more complex than I'd first thought, so I still don't have a firm conclusion about what the problem is or whether multiple problems are involved.

            I have discovered a couple of things of interest that may be contributing factors though:

            1) The transmitted signal from the CS92A seems to be a lot weaker than other Evohome devices, at least in my setup. I have my NanoCUL set up receiving close to the controller and can measure the received signal RSSI for each device for each packet logged - the CS92A is about 15dB weaker than any other device, including the BDR91's that are in the same cupboard as the CS92A.

            The antenna design is also poor and puts the primary radiation axis in the horizontal plane. Below is a picture of the PCB. I've drawn a red line over the (PCB) antenna which runs along the top and down the right hand side: (left hand side relative to the front of the case)



            This is presumably an end fed 1/4 wave with the feed point being the transmitter near the top left of the board. Unfortunately this means the majority of the radiation is horizontally polarised because not only is the horizontal section of antenna longer, most radiation will come from the low impedance end close to the transmitter and not much from the open circuit at the high impedance end of the vertical section. So very little of the radiation is vertically polarised.

            The horizontal radiation will be at a maximum perpendicular to the plane of the device and fall off significantly to the sides. My controller is at approximately a 45 degree angle to the left so this is a problem.

            So I tried rotating the whole CS92A counter clockwise 90 degrees on the wall (it just has one screw holding it for now) to make the primary radiation axis vertical (and therefore omni-directional in the horizontal plane) and sure enough the RSSI at the receiving point has gone up by approx 15dB, and so far no comms errors although it's too early to tell for sure.

            2) The built in signal test function in the Evohome and CS92A seems to be pretty useless - even with the very weak signal the Nano was reporting it was giving a 5/5 result.

            3) The CS92A is difficult to decode with the NanoCUL with some errors reported, while all other devices in the system decode without errors. The error rate seems to go up after the device has been running a long time and comes down again after power cycling the CS92A. Most peculiar. This thing is a riddle inside a riddle.
            Last edited by DBMandrake; 18 February 2020, 01:56 PM.

            Comment

            • G4RHL
              Automated Home Legend
              • Jan 2015
              • 1580

              #66
              The analysis from DBMandrake is helpful and makes lots of sense. Whilst at times I wondered whether interference was the cause of the lost contact with the CS92A I was never convinced for everything else had no problem. It also is not a frequent occurrence but does happen, and not at any particular time other than usually when the HW is off.

              I have been away for a couple of days. I switched all to Away with a minimum setting of 5C. The night before I left to come home I checked and all worked, house was cold and HW was down to about 28C. The morning I departed to return I checked and there was a blank for HW. My guess was the Control Panel had lost contact with the sensor but if I checked again later all would be good. It was. Checking the log when I got home showed that contact had been lost with the sensor around the time that I first checked.

              I have now put lithium batteries in the sensor and may well consider rotating it as in DBMandrake’s case. My sensor is more then the minimum distance from other Evohome gear, it’s Relay is to its left and about the 10 o clock position. The Control Panel is on a different floor, below the sensor and at about the 7 o’clock position to it.

              I will see first if using lithium batteries reduces instances of lost contact but it may be a 45 degree turn to the left of the sensor could help.

              Talking of batteries, I used to use the Industrial AAs bought from Amazon which are said to be the same as Duracells. No issues, but my last batch are Amazon’s own badged version. I am getting the same life out of Amazon’s own version.

              Comment

              • bruce_miranda
                Automated Home Legend
                • Jul 2014
                • 2307

                #67
                Isnt Away set to 5C, the same as Off?

                Comment

                • G4RHL
                  Automated Home Legend
                  • Jan 2015
                  • 1580

                  #68
                  Originally posted by bruce_miranda View Post
                  Isnt Away set to 5C, the same as Off?
                  Yes. I use Away as it switches all off. Easier.

                  Comment

                  • mtmcgavock
                    Automated Home Legend
                    • Mar 2017
                    • 507

                    #69
                    Originally posted by G4RHL View Post
                    Yes. I use Away as it switches all off. Easier.
                    Without getting off topic I find 5oc is too cold, i've adjusted my Away mode to 11oc - I find it a happy medium between it keeping the house aired and not coming on too often.

                    Useful to know about turning it counter clockwise - I shall fit them that way from now on!

                    Comment

                    • bruce_miranda
                      Automated Home Legend
                      • Jul 2014
                      • 2307

                      #70
                      Sorry to ask, but why not use the Heating Off button, which is also one click? Is it the HW cycle that you are trying to avoid? Also depending on your pipe runs, 5C detected in a room may not be high enough to avoid freezing. An 7-8C Away might actually be better and also then you have the 5C Off too.

                      Comment

                      • mtmcgavock
                        Automated Home Legend
                        • Mar 2017
                        • 507

                        #71
                        Originally posted by bruce_miranda View Post
                        Sorry to ask, but why not use the Heating Off button, which is also one click? Is it the HW cycle that you are trying to avoid? Also depending on your pipe runs, 5C detected in a room may not be high enough to avoid freezing. An 7-8C Away might actually be better and also then you have the 5C Off too.
                        Heating Off just does as it says, Heating Off. It doesn't turn the HW schedule off, so if you are away it isn't useful unless you want a tank full of HW at home!

                        But yes I agree, 5oc isn't high enough. If your room is 5oc then underfloors, in voids etc will be much less especially with draughts. Hence why I have mine on 11oc, I find this the best set point for being away. I then have Heating Off to 8oc in EvoHome settings should anyone accidentally knock it onto this.

                        Comment

                        • DBMandrake
                          Automated Home Legend
                          • Sep 2014
                          • 2361

                          #72
                          Originally posted by G4RHL View Post
                          The analysis from DBMandrake is helpful and makes lots of sense. Whilst at times I wondered whether interference was the cause of the lost contact with the CS92A I was never convinced for everything else had no problem. It also is not a frequent occurrence but does happen, and not at any particular time other than usually when the HW is off.

                          I have been away for a couple of days. I switched all to Away with a minimum setting of 5C. The night before I left to come home I checked and all worked, house was cold and HW was down to about 28C. The morning I departed to return I checked and there was a blank for HW. My guess was the Control Panel had lost contact with the sensor but if I checked again later all would be good. It was. Checking the log when I got home showed that contact had been lost with the sensor around the time that I first checked.

                          I have now put lithium batteries in the sensor and may well consider rotating it as in DBMandrake’s case. My sensor is more then the minimum distance from other Evohome gear, it’s Relay is to its left and about the 10 o clock position. The Control Panel is on a different floor, below the sensor and at about the 7 o’clock position to it.
                          Touch wood I have had no comms errors since rotating it. (Whereas Lithium batteries alone didn't cure it)

                          Whether the polarisation helps may depend on the orientation of the CS92A relative to where the controller is - if the controller is perpendicular to the wall the CS92A is on horizontal polarisation may be fine, but in my case it's approximately 45 degrees to the left, so regardless of whether I fit it on that wall or the one at 90 degrees to the left of that, there is still a 45 degree angle to the controller.

                          So in this situation vertical polarisation which is omni-directional in the horizontal plane is going to be a better choice. In my particular case the signal increased by about 15dB by rotating it which is not insignificant.

                          If you do try turning yours 90 degrees I'd be interested to know if it helps. It can take a long time to tell for sure though as mine could still go for weeks without problems before... if it goes for a few months without comms errors or overshoots then I might consider it solved.

                          Comment

                          • DBMandrake
                            Automated Home Legend
                            • Sep 2014
                            • 2361

                            #73
                            Originally posted by mtmcgavock View Post
                            Without getting off topic I find 5oc is too cold, i've adjusted my Away mode to 11oc - I find it a happy medium between it keeping the house aired and not coming on too often.
                            I've set my Away to 10 degrees as well. Heating Off and Away have different use scenarios.

                            Heating Off is for summer when you just want to completely turn off the heating schedule but still allow hot water. Since it's summer there's no chance of the house getting extremely cold 5C is OK as an off setting.

                            Away mode is when you're away from the house, possibly for extended periods of time, and including winter.

                            The default for Away is actually 15C not 5C, as far as I can remember ?

                            Useful to know about turning it counter clockwise - I shall fit them that way from now on!
                            I'm not guaranteeing that that's optimal for all installations - but on an installation where the system is having comms errors with the CS92A and other things have been checked it's certainly worth trying, even if it looks a little strange!

                            Comment

                            • bruce_miranda
                              Automated Home Legend
                              • Jul 2014
                              • 2307

                              #74
                              I've finally said goodbye to batteries in my CS92A today. I really cant see why Honeywell thinks a battery powered HW sensor is really essential. There won't be too many HW installations that don't have power close by. And since the BDR91 that goes with it is mains powered, this is hardly a self install product anyway.

                              Comment

                              • G4RHL
                                Automated Home Legend
                                • Jan 2015
                                • 1580

                                #75
                                Originally posted by bruce_miranda View Post
                                I've finally said goodbye to batteries in my CS92A today. I really cant see why Honeywell thinks a battery powered HW sensor is really essential. There won't be too many HW installations that don't have power close by. And since the BDR91 that goes with it is mains powered, this is hardly a self install product anyway.
                                I take it a small PSU feeding a low charge equivalent to the two batteries has worked and no more lost contact messages in the Control Panel? Or could it be the repositioning of the CS92A to improve the signal direction? Since I changed my batteries to lithium I have not had any messages but it’s very early days.

                                Comment

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