Sensor Request: Heating flow temperature setpoint value and actual value

[nicx]

I am missing (or I just didn't find them) the sensors for the heating flow temperature. I don't know exactly how they are called in Englisch, in German it's called the "Vorlauftemperatur", which is the target temperature controlled by the configured heating curve.

I checked the sensor sensor.hc_lwt_lwt_setpoint, but it differs a lot to the ESPAltherma sensor for the LWT set point:

For the actual value I found no comparable sensor. Only sensor.hc_unknown_temperature_unknown_q could be a match:

Any hints?

[forTT78]

Hi,
at my installation it's under sensor.hc_sensors_temperature_r2t_leaving_water

Best regards,
Thomas

[nicx]

@forTT78 thanks, I just found this in the documentation:

Temperature_R1T_HP2Gas_Water | Water temperature after heat exchanger and before backup heater or gas boiler
Temperature_R2T_Leaving_Water | Leaving water temperature (after backup heater or gas boiler)
Temperature_R4T_Return_Waterr | Return water temperature

so I think you are right, the R2T temperature should be the right sensor for the current temperature of the heating flow.

But what about the target temperature sensor? The LWT set point as I wrote above seems a bit different. And the timeframe it got updated is very slow, too.

[forTT78]

Hi, it's the target temperature and depends on the ambient temperature (e.g. sensor.hc_sensors_temperature_outside_unit).
With out any averaging it will change as function of the outside temperature.

[nicx]

@forTT78 hm... unfortunately, I can't quite follow. I know that the target temperature for the heating water depends on the outside temperature (weather-compensated). But that was not my question ;)

What we do know so far:
The "Temperature_R2T_Leaving_Water" sensor is the current temperature of the heating water.

My open main question is:
Is the "LWT_Setpoint" sensor is the target temperature for the heating water. Is that correct?

In addition to this question my second question is:
Why is the sensor value of "LWT_Setpoint" that different to the sensor values of the ESPAltherma pendant (see first two screenshot above)? And why is it updating so slowly in comparison?

[forTT78]

@nicx

What we do know so far: The "Temperature_R2T_Leaving_Water" sensor is the current temperature of the heating water.

My open main question is: Is the "LWT_Setpoint" sensor is the target temperature for the heating water. Is that correct?

Yes.

In addition to this question my second question is: Why is the sensor value of "LWT_Setpoint" that different to the sensor values of the ESPAltherma pendant (see first two screenshot above)? And why is it updating so slowly in comparison?

From my understanding, the value from ESPAltherma looks more like the (internal) calculated value for target temperature, based on the heating curve and ambient temperature. For "LWT_Setpoint" I can set only whole numbers, no decimal numbers.

But I don't know exactly in which situation daikin uses one of the setpoint values first.

[Arnold-n]

Indeed LWT_Setpoint is the target. On my hybrid system, it has an accuracy of 0.1C and is equal to ESPAltherma's output. On my EBLA monoblock, it has an accuracy of 1.0C and I do not yet know what ESPAltherma reports. Perhaps the data provided over P1/P2 is rounded by the Daikin unit for some units.
Because P1P2MQTT has a higher update frequency than ESPAltherma it also implements some hysteresis filtering to avoid overloading HA.

[nicx]

@Arnold-n thanks for explanation. which hybrid system dot you have? Mine is an Daikin Altherma 3 R ECH2O ERGA08EVH + EHSXB08P30E. So as far as I understand this should be a hybrid system, too. I am just wondering because all other temperature sensors have a 0.1C accuracy.

[Arnold-n]

Mine is an older EHYHBX08AAV3 from 2014, a hybrid heat pump/gas boiler system in cascade. I think your system is an integrated heating/DHW boiler system but not 'hybrid' in the sense of being a heat pump/gas boiler?

[nicx]

@Arnold-n you are right, it's not "hybrid" in that sense of being. :)