So today we were lucky enough to have great weather for my IFTTT rule of switching the heating off past a certain temperature, to kick in. I confirmed that the control panel showed that all zones were off and the Heating Off quick action was in operation. What I also realised was that in Heating Off mode, no overrides are allowed via the controller - unlike some other quick actions. Domoticz confirmed that there was no Heat Demand too from any zone.
So I went to one of the radiator controllers and turned the setpoint to 0.5C over the current room temperature. The controller was none the wiser and just showed the Heating completely off, Domoticz said the same because I guess it's just saying what the controller is telling it. But to my surprise the boiler fired up! Because I have OT I wanted to check what the target flow temperature was set in this condition. It said 49C. So not 90C (theoretical max) or even 65C (boiler max set).
Warm water started flowing through my system and the radiators that were opened up slightly. But Evohome and Domoticz still displayed, full Heating Off and all setpoints at 5C.
It was only when I looked at the Heat Demand screen did it show the zone that I had overridden with a 50% Heat Demand.
I then set another zone manually to 0.5C over setpoint and it too jumped to 50% Heat Demand, but Evohome kept the overall Heat Demand down and continued to keep the Target Flow at 49C. Same thing continued with 3 zones too. It proved that Evohome can deal with multiple zone Heat Demands, and if the temperatures are not far from the setpoint it won't kick the boiler into full.
It also highlights an Evohome bug, don't think your heating around the house is OFF, just because your controller or your app says so. Local Override display obviously don't work when Heating Off is in operation. So your kids could be playing with the radiator controllers and you'll be scratching your head trying to work out why the boiler is on in the middle of summer. The App and the controller showed no signs of me changing the setpoint while the Heating Off was in operation.
Thank you Dan for taking the time to code the Heat Demand functionality into Domoticz.
p.s. : What I have noticed is that the boiler is run almost at 50% max flow temperature for a 0.5C difference to setpoint, 1C difference to setpoint and it runs at 75%, anything higher than 1C difference and the boiler is kicked to max. This demand could be even for a single zone, so all the zones can experience overshoots if they have any Heat Demand and a single zone is below 1C from set point.
So I went to one of the radiator controllers and turned the setpoint to 0.5C over the current room temperature. The controller was none the wiser and just showed the Heating completely off, Domoticz said the same because I guess it's just saying what the controller is telling it. But to my surprise the boiler fired up! Because I have OT I wanted to check what the target flow temperature was set in this condition. It said 49C. So not 90C (theoretical max) or even 65C (boiler max set).
Warm water started flowing through my system and the radiators that were opened up slightly. But Evohome and Domoticz still displayed, full Heating Off and all setpoints at 5C.
It was only when I looked at the Heat Demand screen did it show the zone that I had overridden with a 50% Heat Demand.
I then set another zone manually to 0.5C over setpoint and it too jumped to 50% Heat Demand, but Evohome kept the overall Heat Demand down and continued to keep the Target Flow at 49C. Same thing continued with 3 zones too. It proved that Evohome can deal with multiple zone Heat Demands, and if the temperatures are not far from the setpoint it won't kick the boiler into full.
It also highlights an Evohome bug, don't think your heating around the house is OFF, just because your controller or your app says so. Local Override display obviously don't work when Heating Off is in operation. So your kids could be playing with the radiator controllers and you'll be scratching your head trying to work out why the boiler is on in the middle of summer. The App and the controller showed no signs of me changing the setpoint while the Heating Off was in operation.
Thank you Dan for taking the time to code the Heat Demand functionality into Domoticz.
p.s. : What I have noticed is that the boiler is run almost at 50% max flow temperature for a 0.5C difference to setpoint, 1C difference to setpoint and it runs at 75%, anything higher than 1C difference and the boiler is kicked to max. This demand could be even for a single zone, so all the zones can experience overshoots if they have any Heat Demand and a single zone is below 1C from set point.
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