Switch for Stiebel Eltron ISG Is cooling (stiebel_eltron_isg_is_cooling)

[Nusserdt]

ISG Provide under

Programme > Kühlzeit (s=3,5)

time for active cooling. These times get ignored by my LWZ5 CS Premium (maybe this setting is not related to active cooling).

Unfortunately cooling function consumes about 0,7 kWh. Overnight it would takes a lot from the electrical storage. Ofc cooling on night time is much more efficient, but on day time I have practically unlimited power from PV.

I would be great to enable/disable cooling with Home Assistant and an time based automation.

If this is not possible to implement:

could it be possible to disable cooling indirectly over the Operation Mode? For example switch to Manual Operation Mode on night time?

Happy to hear from you!

[pail23]

I have not found any modbus register which could allow to disable cooling. Please provide my a hint in case you have found a related register.

What you could try: setting the target temperatures to a very high value during night. Maybe the cooling then stops because the target temperature is above the actual temperature.

[Nusserdt]

Hey @pail23 thanks for your reply. Worth a try to modify the temperatures, but Stiebel Eltron seems have some inconsistency with there cooling settings.

For cooling there exist own temperatures. In the cooling main menu you have the HK-TEMP. KÜHLEN

and in under RAUMTEMPERATUREN HK1 you can find the RAUMTEMP. TAG (16,0 °C, this is not mirror to HEIZEN -> RAUMTEMPERATUREN HK1 -> RAUMTEMP. TAG).

Both temperatures can't setted by extension. Additionally I also try already raise the RAUMTEMP. NACHT to prevent cooling at night, but Stiebel Eltron ignoring this setting. So I think the key temperature is under

KÜHLEN -> KÜHLBETRIEB HK1 -> HK-TEMP. KÜHLEN

[guevara777]

I think you should be able to set the cooling-temperatures via the following Modbus-Registers:

For LWZ i found these registers for the room-temperatures for cooling:

I also found this documentation in the manual for the LWZ: see: Link

My parents own a HK 230 Premium Heat Pump which is also able to cool. To activate the cooling-function there, i would need a device that measures the humidity in the house. Stiebel Eltern sells that device (FET) for almost 300 Euros... For WPM i found these registers for the HK-temperatures for cooling:

[pail23]

I have added the sensor for WPM mentioned by @guevara777 in the release 2023.8.1. The are named "Fan cooling ..." and "Area cooling ..."