I have a Daikin Altherma 3 11kW heat pump and underfloor heating with a multi-zone Danfoss Icon controller. In addition I have a buffer tank of 50L installed.
The Danfoss Icon controller can only provide a dry contact on-off signal which is not compatible with the Altherma. Therefore my installer has configured the heat pump to run in LWT weather dependent (WD) mode.
The LWT mode seems pretty inefficient as it constantly keeps the buffer tank at WD temperature although there is no heat request from my underfloor heating.
To optimise this I consider switching to RT mode and switch the heat demand by means of 230V relay (either directly from the Danfoss controller dry contact or controlled over Zigbee with Home Assistant). The Altherma supports by means of an external thermostat which can turn the heat demand on/off.
In my understanding the heat pump should not run when there is no heat demand in RT mode from the external thermostat. And thus result in lower energy consumption.
Is this correct?
Are there any other suggestions for improving my setup?