Evohome Hot water problems

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  • bruce_miranda
    Automated Home Legend
    • Jul 2014
    • 2307

    #31
    I am trying something else. I have the PSU for my evohome wall mount housed quite close to the HW sensor. So I plan to run a 3.3V low ripple voltage regulator straight into the HW sensor. That should see the end of any battery requirements there. The HW sensor should have come with a powered option.

    Comment

    • DBMandrake
      Automated Home Legend
      • Sep 2014
      • 2361

      #32
      Originally posted by bruce_miranda View Post
      I am trying something else. I have the PSU for my evohome wall mount housed quite close to the HW sensor. So I plan to run a 3.3V low ripple voltage regulator straight into the HW sensor. That should see the end of any battery requirements there. The HW sensor should have come with a powered option.
      Let us know how that goes. Hopefully 3.3 volts (1.65 per cell) is sufficient to avoid unnecessary power saving measures in the device as that's basically exactly the new voltage of a standard Alkaline cell. The Lithium's do start a bit higher but I think they drop to around 1.7 volts after a bit of use and then stay above 1.6 volts over most of the discharge cycle. Certainly at the microscopic currents levels that this device uses.

      As well as that the Lithium's supposedly have a 20 year shelf life which implies that they should last a very long time in a device with very low current drain, as the self discharge in other cell types is probably similar to what the device itself actually uses, so operation time is limited in good part by the self discharge of the batteries...

      If I have any further problems with mine I'll report back. So far it is behaving itself...
      Last edited by DBMandrake; 28 January 2020, 10:00 AM.

      Comment

      • G4RHL
        Automated Home Legend
        • Jan 2015
        • 1580

        #33
        Originally posted by bruce_miranda View Post
        I am trying something else. I have the PSU for my evohome wall mount housed quite close to the HW sensor. So I plan to run a 3.3V low ripple voltage regulator straight into the HW sensor. That should see the end of any battery requirements there. The HW sensor should have come with a powered option.
        The results of this will be helpful. With a regulated even supply it may stop lost contact messages that occasionally occur with the sensor. I get them, not regularly, but they do appear. I ignored them unless I am told the battery is low.

        Lithium’s might be a good idea.

        Comment

        • bruce_miranda
          Automated Home Legend
          • Jul 2014
          • 2307

          #34
          I plan to use a "TPS7A4700 Low Noise RF Power Module" which is a massive overkill for the job. Just need to work out if I wire this in permanently or I use the battery eliminator style blanks.

          Comment

          • mtmcgavock
            Automated Home Legend
            • Mar 2017
            • 507

            #35
            I've always used Lithium ones and not had any issues, perhaps that's the cure? I try and use Lithium ones in all the HR92s too.

            Comment

            • DBMandrake
              Automated Home Legend
              • Sep 2014
              • 2361

              #36
              Originally posted by mtmcgavock View Post
              I've always used Lithium ones and not had any issues, perhaps that's the cure? I try and use Lithium ones in all the HR92s too.
              Now you tell us...

              What prompted you to try Lithium in the CS92A when the installation manual says Alkaline only ? I'm doing it against the recommendation in the manual specifically due to us now suspecting there is an issue with these units not working reliably at lower (but normal for Alkaline) voltages.

              I've always used Alkaline in my HR92's - as you can buy them in packs of 40 very cheaply. I haven't found any source of Lithium's in bulk where the extra expected lifetime of the Lithium's would outweigh the considerably greater cost.

              I guess if you want a low maintenance system which will go for as long as possible between battery swaps Lithium makes sense, but if you're a cheapskate like me Alkaline is more economic. As long as I have a large pack of new batteries waiting to go I don't mind the occasional low battery alert and battery swap.

              I'm getting about 1 1/2 years from Alkaline's despite having all my HR92's in Stroke 1 mode. My work colleague with Tado V3 says he's having to replace the batteries in his TRV's every 9-12 months....!

              I've also fitted two new 2500mA NiMH cells in the Evotouch itself as I think the original factory supplied ones are a bit stuffed after sitting on the wall mount for 3 1/2 years...as they don't seem to last long when it is removed. I'll test the old ones later with my discharge tester to see what usable capacity they had left!
              Last edited by DBMandrake; 29 January 2020, 10:12 AM.

              Comment

              • mtmcgavock
                Automated Home Legend
                • Mar 2017
                • 507

                #37
                Originally posted by DBMandrake View Post
                Now you tell us...

                What prompted you to try Lithium in the CS92A when the installation manual says Alkaline only ? I'm doing it against the recommendation in the manual specifically due to us now suspecting there is an issue with these units not working reliably at lower (but normal for Alkaline) voltages.

                I've always used Alkaline in my HR92's - as you can buy them in packs of 40 very cheaply. I haven't found any source of Lithium's in bulk where the extra expected lifetime of the Lithium's would outweigh the considerably greater cost.

                I guess if you want a low maintenance system which will go for as long as possible between battery swaps Lithium makes sense, but if you're a cheapskate like me Alkaline is more economic. As long as I have a large pack of new batteries waiting to go I don't mind the occasional low battery alert and battery swap.

                I'm getting about 1 1/2 years from Alkaline's despite having all my HR92's in Stroke 1 mode. My work colleague with Tado V3 says he's having to replace the batteries in his TRV's every 9-12 months....!

                I've also fitted two new 2500mA NiMH cells in the Evotouch itself as I think the original factory supplied ones are a bit stuffed after sitting on the wall mount for 3 1/2 years...as they don't seem to last long when it is removed. I'll test the old ones later with my discharge tester to see what usable capacity they had left!
                Well...I don't always use them in all the CS92As I fit. The main issue being is our suppliers don't always have them - and cost. I've bulk bought a load online for the systems we maintain and fit.

                I've just checked my own and it's got normal AAs in at the minute. It did have Lithium ones in to start with, and then had an error message after about 2 years of use so I swapped them for what I had in the kitchen draw at the time! The system I fitted that has a CS92A that has issues is very sensitive to drop in battery voltage - next time I'm round I think i'll swap out the batteries for some lithiums.

                The prompt, well I was fitting Lithium ones in the HR92 and I thought it just made sense to fit them in the CS92A. They last longer that was my thought! Tbh I didn't even read the manual.

                The first ever system that I fitted I used Lithium batteries, I go back yearly to service the boiler. When I went last year the system will be now 4 years old, and she's never replaced any of the batteries and they were all still on two bars. So I try to fit lithium (budget permitting) on systems I install now.

                However one system I fitted about a year ago was on the normal AA that come in the box, supplier didn't have enough Lithium ones at the time (larger system) so I just went with what came with system. They were having to change them every 9-12 months too, the system seemed to be eating through batteries. So i've swapped them all for lithium now with the HR92s on the correct setting, will see how long they really last.

                My own system which is about 3 years old are still on the original AAs, bar three I think, I haven't changed many at all - and my system is on all day. The only thing that I can think of is in a poorer insulated house/colder house that the HR92s are going to be doing at lot more work, which is the conclusion I came to with the system above. My house is fairly well insulated so the HR92s probably do little work.

                Comment

                • bruce_miranda
                  Automated Home Legend
                  • Jul 2014
                  • 2307

                  #38
                  I hear all this talk about Evohome eating batteries but I have a system will all HR80s and I don't have any of these issues. A pair of AAs alkalines will last me well over 3 years in all my devices. And the HR80 is actually a lot more chatty over the radio than the HR92s, so something must have changed to cause the extra consumption. And I use the Costco Kirkland batteries too, nothing fancy.

                  Comment

                  • DBMandrake
                    Automated Home Legend
                    • Sep 2014
                    • 2361

                    #39
                    Well that didn't last long. Before I went to bed last night I was greeted with a big red "comms fault hot water sensor".

                    I went to press the test button on the CS92 and it merrily flashed 5 times for excellent signal, even as the controller was still reporting no hot water temperature. Of course as soon as I removed the batteries and refitted them again the fault went away - as it always does.

                    Signal test from the controller end also shows perfect:



                    In a slight fit of disgust I actually removed it off the wall and refitted it in its original location from two years ago (which theoretically has a more direct signal path) and tested the signal there - also perfect 5/5 / excellent signal, I then went to bed. On checking the fault log book again in the morning I discovered that not only had there been an additional fault earlier the previous day I hadn't noticed, there was another fault in the middle of the night after moving the sensor and re-seating the batteries a second time:



                    It can clearly be seen in my temperature graphs that despite being within the 49-54 degree proportional band (where it should send frequent updates) at the time of the faults, nothing was heard by the controller for over three hours each time:



                    To be honest at this point I'm utterly fed up and disgusted with this unreliable piece of junk, (CS92) it really is rubbish. The rest of the Evohome system has minor quirks but basically works reliably enough, however, the CS92 really is junk, and I simply can't recommend Evohome to anyone who needs hot water control as a result, and I actually kind of regret using Evohome to control my hot water after all the problems I've had. I'm considering changing to a separate hot water timer with wired sensor.

                    I've had the CS92 replaced under warranty when it was 6 months old, (improvement but not cured) I've relocated it twice, (slight change but not cured) I've discovered and tweaked the loose battery contacts, (improved a lot but not cured) I've tried different batteries etc...

                    I've wasted dozens upon dozens of hours in the last 3 years troubleshooting this small infernal white box and I can't come to any other conclusion than that it has a software bug or hardware design or manufacturing flaw which causes it to stop sending for hours at at a time for unknown reasons. There are too many other people reporting identical symptoms for it to be just one or two bad units, especially when I'm onto my second unit now.

                    I have 3x BDR91 in the same closet as the CS92, (yes they are all spaced adequately apart from each other) they never have any comms issues, and in the case of a BDR91 if they lose comms for 45 minutes the red light would start flashing anyway. (which it never does) To get a comms error from the hot water sensor it has to lose comms for 3 hours.

                    The CS92 and BDR91's are only 5 metres from the controller, through a single wall and a glass door. Signal strength when testing is always perfect.

                    In my opinion there is no way this is a genuine comms issue caused by interference from other devices, metal objects, swamp gas etc... if it was sending many times an hour that would be an awful lot of coincidences for the controller to not hear from it for over 3 hours. No, the device simply decides to stop sending for long periods of time. Sometimes less than three hours (so a fault isn't logged, but you may get an overshoot) and sometimes more than three hours. (so that a fault is logged, and hot water heating is disabled)

                    At this point I have completely run out of ideas. It's long out of warranty now and there's no way I'm ponying up money to buy another defective by design CS92 at my expense that will almost certainly not fix the problem, just like the first replacement didn't.

                    I have a NanoCUL on the way which will let me directly monitor the wireless comms between the devices however I fear that it will only confirm what I already know - that the CS92 just goes silent for long periods of time for unknown reasons, and confirming that still doesn't help me solve the problem.

                    Come on Honeywell, you really need to sort this out and release a CS92B!
                    Last edited by DBMandrake; 30 January 2020, 03:32 PM.

                    Comment

                    • DBMandrake
                      Automated Home Legend
                      • Sep 2014
                      • 2361

                      #40
                      Just thought of something.

                      1) Does anyone remember for certain what the default hot water set point and differential is in the Evotouch on a factory reset controller when you first add hot water control ?
                      2) Those who say they have little to no problems with their hot water sensor - what is your hot water set point and differential ? Did you leave it on the defaults or customise it ?
                      3) Those who do have similar problems to me, what hot water set point and differential do you use ?

                      I'll go first - I have mine set to 54C and a 5 degree differential. I believe the default is a 10C differential and approx 60C for the set point...
                      Last edited by DBMandrake; 30 January 2020, 11:49 PM.

                      Comment

                      • mtmcgavock
                        Automated Home Legend
                        • Mar 2017
                        • 507

                        #41
                        Think mine is 55oc with a dif of 7oc with a 2 min overrun. Usually ends up at 56/57then. Think the default is 55 not 60.

                        I was going suggest have you tried putting the Panel on its stand and placing nearer the sensor? Rather than just leaving where you usually leave it...might eliminate any interference issues if that is the problem.

                        Comment

                        • DBMandrake
                          Automated Home Legend
                          • Sep 2014
                          • 2361

                          #42
                          Yeah I've tried it on a stand closer to the boiler closet. It's not a signal strength or interference issue. No other devices on the system are affected including those in the same closet.

                          Comment

                          • mtmcgavock
                            Automated Home Legend
                            • Mar 2017
                            • 507

                            #43
                            Have you ever considered it could be the physical sensor that’s causing the issue (the bit that straps to the tank) resistance dropping out causing the CS92A not to behave

                            My system I use the probe, whereas yours I’m assuming you use the strap on sensor being a gravity fed system.

                            Comment

                            • bruce_miranda
                              Automated Home Legend
                              • Jul 2014
                              • 2307

                              #44
                              mine used to be 60c and 10, recently I moved it to 55 and 10, to do some testing. No issues with both settings.

                              Comment

                              • G4RHL
                                Automated Home Legend
                                • Jan 2015
                                • 1580

                                #45
                                Originally posted by DBMandrake View Post
                                Just thought of something.

                                1) Does anyone remember for certain what the default hot water set point and differential is in the Evotouch on a factory reset controller when you first add hot water control ?
                                2) Those who say they have little to no problems with their hot water sensor - what is your hot water set point and differential ? Did you leave it on the defaults or customise it ?
                                3) Those who do have similar problems to me, what hot water set point and differential do you use ?

                                I'll go first - I have mine set to 54C and a 5 degree differential. I believe the default is a 10C differential and approx 60C for the set point...
                                Mine is set to 55C and 10 degree differential and 10 minute overrun. I think the 10 degree differential and 10 minute overrun may be the default settings. I set my temperature at 55c as a compromise between 50c as being the border line for bug killing and 60c being too hot. I don’t have problems other the occasional message the sensor has lost contact. Not very often at that and I ignore it.

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