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Thread: optimisation issue

  1. #1
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    Default optimisation issue

    Hi,
    I tried to activate the optimisation function of my evohome with optimised start a month ago and since then, I see no change on my system.
    I configure some hour for a room and at the hour I configure, the controller show "opt" but still don't heat. I have to wait 20 minutes for the system to start heating.
    I thought that the hour we configure was the hour at which we want the temperature to be the configured one.
    2 solutions:
    - I didn't configure it correctly
    - There is a bug.

    Any idea of what's happening?
    Thanks

    Mat

  2. #2
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    Hi,

    If the controller is showing 'Opt' on a zone then I believe that this indicates that it has automatically altered the setpoint on the zone, bringing forward the time at which it increases the setpoint to help ensure that the zone reaches the setpoint temperature at the time you originally set. It will still take 20 mins or more for the radiator to reach it's normal temperature and the room temperature to increase. However, you should notice that the setpoint change occurs earlier that the time you set for the change, if the room requires additional time to reach temperature. On the newer Wifi controller the symbol appears as a wiggly arrow.

    Dan

  3. #3
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    more explaination: I have configured 15C for cold time (out of home) and 19C for hot time (in house).
    The hot time is configured to 18:30.
    When I come home around this time, before this hour, the controller is still in cold temp, after the hot time, it's still in cold temperature but with "opt" and it come to hot temperature after 20 minutes.
    Always the same time until I configure it.
    Mat

  4. #4
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    Hi Mat,

    Can you check your optimisation settings? Here's the page from the FAQ doc for your Evohome controller (I think you have the non-wifi colour version). Press and hold the settings button to get to the first menu. Make sure that 'Optimum Start' is selected.

    Optimisation.JPG

  5. #5
    Automated Home Legend paulockenden's Avatar
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    Default

    Optimised start times definitely do vary. I have mine set to an hour, and most times the system uses that full hour (and so it up to temp WELL before the start time as my house heats quickly). But if the room temp is closer to the next setpoint then optimisation doesn't kick in for the full hour - it definitely varies.

    But it always seems to take a pessimistic view, and over-does things. I guess that's the only way it can guarantee to be up to heat, at the time you specify.

    Shame there isn't an 'expert' mode, that allows people to tinker with the various parameters involved.

  6. #6
    Automated Home Jr Member zcapr17's Avatar
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    Quote Originally Posted by thios View Post
    more explaination: I have configured 15C for cold time (out of home) and 19C for hot time (in house).
    The hot time is configured to 18:30.
    When I come home around this time, before this hour, the controller is still in cold temp, after the hot time, it's still in cold temperature but with "opt" and it come to hot temperature after 20 minutes.
    Always the same time until I configure it.
    Mat
    From this description it sounds like you have "Delayed Start" configured instead of "Optimum Start" (which will bring the setpoint forward).

    To backup what Paul's written, here's a chart of my Kitchen thermostat showing periods of "Optimum Start" and "Optimum Stop" in operation...

    Green shading is periods of optimisation, orange is periods of heating. On this particular day, Evohome raised the setpoint 45 mins early in the morning, and managed to reach the setpoint 15 mins early. In the evening, Evohome dropped the setpoint a whole hour early. I typically see periods of optimisation anywhere from 5mins to an hour.
    Attached Images Attached Images
    Last edited by zcapr17; 15th April 2016 at 12:11 AM.

  7. #7
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    Quote Originally Posted by zcapr17 View Post
    From this description it sounds like you have "Delayed Start" configured instead of "Optimum Start" (which will bring the setpoint forward).
    I think you've hit the nail on the head there... I had forgotten that the Delayed Start option even existed when I was trying to think of explanations for the problem described.

    Personally I don't understand the purpose of Delayed Start, so I didn't give it a further thought after reading about it during initial setup...

    Optimial start seems to be working reasonably well for me at the moment - I have maximum startup time set to 2 hours and it rarely uses the full amount, and typically zones are all up to temperature about 15-30 minutes before scheduled times unless I have pulled the carpet out from under its feet by dropping the flow temperature suddenly one day or leaving a towel over a radiator that didn't previously have one.

    (Both of which obviously slow room heat up in a way that the Evohome could not predict ahead of time)

    I did have some problems for a while where one zone was heating up way too early and didn't seem to adapt correctly, but it appears that you can reset the optimisation learning of a zone by re-binding a different temperature sensor. For example in a zone where the HR92 was the sensor I would bind the evotouch internal sensor as the new temperature sensor for the zone (assuming it was not already being used) and then some time later bind the HR92 as sensor again without changing anything else.

    I can't be certain but this did seem reset the learning strategy as it started to adapt again over a day or two.
    Last edited by DBMandrake; 17th April 2016 at 07:05 PM.

  8. #8
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    I think you're right.
    I have a french version and the translation is not the good one.
    If I refer to the FAQ Dand include, the "delayed start" has been translated in french to something like "optimisation at start" and "optimum start" as "maximum duration of optimisation" that is not very understandable.
    I will start this one, I hope the position in the interface is the same...
    Honeywell need a better translater, or a better documentation (never find one in french or in english that explain this functionnality).

  9. #9
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    Is there a way to reset the previous optimisation data that may be stored and force the controller to relearn from scratch?

  10. #10
    Automated Home Legend paulockenden's Avatar
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    Yeah - just set the temp sensor for the zone to be the Evohome controller, wait ten minutes, then set it back to the proper temp sensor. That should kick off a full learning phase for that zone, including optimisation.

    I think!

    P.

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