Heating with backup heater -

[d3zit]

Do you know which parameters allow you to understand if the heat pump is heating the water with the help/or only with the backup heater?

If operation_mode is Heating and 3_way_valve is ON then the heatpump is heating up DHW
If operation_mode is Heating, 2_way_valve is ON and 3_way_valve is OFF is heating the water for heating system

Apparently when the system is heating the water with the backup heater it's not in one of the previous states.

Thanks!

[Lectere]

good question, I'd like to know that too...

[Freeman656]

Hi !
Very good question :)
@raomin any idea ?

[raomin]

I'm using these:

BUH Step1
BUH Step2

[Freeman656]

Do you know why there are 2 values ? In case of two heat resistances in some models ?

[raomin]

2 power levels. Something like 1kw and 2 kw. Might 2 resistances...

[d3zit]

In this graph I plotted:

Yellow: power consumption heat pump (shelly clamp)
Blue: power consumption of the heat pump resistance (another shelly clamp).
Orange: OAI (outside air temperature).
Green: DHW temperature

Resistance starts randomly and I'm unable to detect it as - apparently - when it starts the heatpump is not in heating mode.
Gray: standby
Blue: DHW heating
Green: cooling

Heating with resistance consumption ends up in the standby because I'm unable to correctly detect the status and address the energy consumption accordingly

[raomin]

Add these to your graph:
BUH Step1
BUH Step2

It should show the resistance activity

[Freeman656]

I added the BUH step 1 and 2 in my HA config and I get the following data:
Strange to see that the BUH step 1 gets activated during a few minutes as it's almost 30° outside...

[raomin]

The HP, low temp, cannot probably heat more than 50 even with 30 outside.
@KalaNagHTD probably knows this...

[d3zit]

In my case BSH is activated instead of BUH

I can confirm that the resistance is using approx. 1 kW
The heatpump waited approx. 30mins before starting the BSH

My OAT sensor is placed right behind the fan of the external unit. As soon as the fan starts spinning the temperature drops and therefore (I suppose) the Heatpump is tricked into turning on the resistance (??)

Unfortunately it seems that after some time even if IU operation is DHW and BSH are on, resistance is actually off as it doesn't drain power and therefore I'm "unable" to identify when the heatpump is heating with the resistance.

Later on IU operation is DHW, BSH is off.. but the resistance is back on. I know it only because I have a clamp on the resistance circuit, otherwise from Altherma I would be unable to detect this status.

[Freeman656]

I won't do it anyways !! I just want to ensure everything is working as expected :)

[d3zit]

Daikin confirmed today that by default heatpump should stop working at 25, but should be configurable at 35°C

[d3zit]

I also asked if it's possible to move the sensor somewhere else. My heatpump is mounted facing west and therefore after 1pm it sits in plain sunlight reading values much higher then real ones. I'll try to design and build a 3D cage with a small fan to provide continuous active ventilation to the sensor in order to read the real air temperature

[Freeman656]

Really interesting !

[Freeman656]

Do you know which parameter it is ?

[Freeman656]

BSH didn't go up, only BUH for a few minutes.

[mx-vatte]

Are you're sure that you're using the right register configuration regarding your heat pump? Maybe BSH and BSU are switched.

[d3zit]

No. Next month a daikin technician should have a look and let you know. I don't even know how a BUH should look like... do you have photos?

Anyway I can confirm that 25°C is the threshold

[mx-vatte]

This should be the setting [4-02]. After my understanding and observations this is a limit for heating not DHW. I switched it to 19 °C since I don't want that the pump is running every ~3 minutes for ~3 minutes. So over 19 °C outside temp the pump stays of as long the thermostat is off also. But the DHW is heated by the heat pump without any electrical heater (BUH nor BSH).

[Freeman656]

In ESPAlterma config I have :

{0x60,12,305,1,-1,"BSH"},
{0x60,12,304,1,-1,"Palier1 BUH"},
{0x60,12,303,1,-1,"Palier2 BUH"},

And in my heatpump configuration, I don't really know where to look at :)

[bzq-pl]

thank you! need to explore my menu!

[mx-vatte]

Do you have the corresponding "Installer Reference Guide" for you heat pump? On the last pages there is an overview table of all settings.
I went through and noted all settings from my heat pump settings overview in installer mode.

[bzq-pl]

https://www.daikin-ce.com/content/dam/document-library/Installer-reference-guide/heat/ground-to-water-heat-pump/EGSAH-D9W,EGSAX-D9WG_4PEN569820-1B_Installer%20reference%20guide_English.pdf

I have looked at the chapter "Field settings table" but I'm not sure if this is the data I should explore.

[mx-vatte]

This is the chapter/table which I went through. But some settings became clear for me only in connection to the explanations inside the manual. Therefore the search function (field code) inside the PDF is really helpful.

[bzq-pl]

thank you - I need to explore this document in the way you proposed.