Ecodan heated DHW outside of timer window, why?
Yesterday at around 9:45am, the Ecodan sprung into action and heated the DHW tank much to my surprise as I have set the timer on the controller to only heat between 1 and 2pm and if we need more I just do a manual 'Heat Now' via the MEL Cloud app. I definitely did not press 'Heat now' on the app.
Almost 12 months since install and I've never seen it do this.
The only thing of note is that the tank was pretty much cold, we had no major need prior to the 1pm heat up, however I ran the hot tap for quite a while (not too long before 9:45am) to see whether there were any bits of warm water left in there at the top (there wasn't). Could this have made the tank hit a minimum temperature that forces the ASHP to heat the DHW? If so, I don't recall seeing a setting for this in the controller.
Mitsubishi Ecodan 8.5kWh
4.4kW Solar PV
5.2 kWh Battery Storage
1983 build, 300mm loft insulation, cavity wall insulation (beads)
The only other scenario I've noticed a DHW heating run happen is when restarting the system after a power cut. I've seen the tank reading get pretty cool and it still wait for the end of a heating-prohibited schedule period.
By the way, if you want a DHW run faster, start it on the controller rather than the app: rightmost screen button then leftmost on mine, then back out to the front screen for it to activate.
@mjr Thanks, yes mine has been at 8 degrees C some days and still waits until the end of the prohibited window, so very strange.
TBH when I press DHW 'Heat Now' on the app or the tap on the thermostat, every time it's almost instantaneous, it's the heating where I find there is a ~15 minute lag before the Ecodan fires up/stops when the temperature is altered. My main controller is in the loft, but thank you for letting me know.
Mitsubishi Ecodan 8.5kWh
4.4kW Solar PV
5.2 kWh Battery Storage
1983 build, 300mm loft insulation, cavity wall insulation (beads)
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