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Thread: Logging on off

  1. #1
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    Default Logging on off

    Is there a way to see a log of zone on/off times?

  2. #2
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    Quote Originally Posted by davidj View Post
    Is there a way to see a log of zone on/off times?
    What do you mean by on/off times ?

    As the heat demand of zones is proportional the demand from a zone is variable with a whole range of in between values than just on and off.

    So in that sense the question doesn't make sense. What is it you're trying to find out ?

  3. #3
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    I'm trying to establish when the zones ACTUALLY switch on and off.

  4. #4
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    As previously mentioned the zones don't only turn on and off. Even in OFF Evohome keeps the TRVS slightly open, which is why I still keep all my manual TRV heads, for when I want to turn the radiators off to pull them off.
    Any case, there is no way to check the log of these. The only way to know what they are actually doing is to invest in an HGI80 and use some more software like Domoticz to log the Heat Demand messages. Otherwise, you just trust that your schedule is working and watch for the Optimisation icons on the controller, should you have that enabled.

  5. #5
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    Quote Originally Posted by davidj View Post
    I'm trying to establish when the zones ACTUALLY switch on and off.
    If you're just wanting to monitor Optimal Start to graph how early each zones set point changes before the scheduled time then graphing with Domoticz will do that - you don't need an HGI80 to graph measured temperature and set points with Domoticz - you can use the script which connects to the Honeywell API, as I do.

    However if you want to actually graph heat demand (an HR92 requesting the controller to fire the boiler) then you'd need an HGI80 interface with Domoticz - this is currently the only way to see the actual heat demand requests made by individual HR92's. You cannot surmise this information just by comparing set point and current measured temperature, at least when the set point is within +/- 1.5 degrees of the current temperature.
    Quote Originally Posted by bruce_miranda View Post
    Even in OFF Evohome keeps the TRVS slightly open, which is why I still keep all my manual TRV heads, for when I want to turn the radiators off to pull them off.
    That's not actually true. If the set point is at least 1.5 degrees below the current temperature the HR92 will close the valve completely, as in no flow at all. Also if you turn it to the "OFF" position it disables 5 degree frost protect. (Tested by putting one in the freezer ) I don't know if it disables the fortnightly valve exercise regime though, so if a radiator was removed I would not rely on it and use a painters cap instead.

    If the set point is at least 1.5 degrees above the current temperature the valve will fully open. However within the +/- 1.5 degree proportional band the valve position could be anywhere between fully closed and fully open based on factors other than just the current temperature, since it is a full PID controller.

    Only the heat demand reported by Domoticz with an HGI80 will tell you what's really going on within this proportional band in regards to boiler demand.
    Last edited by DBMandrake; 16th January 2017 at 12:06 PM.

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