vandermark1977 / Domoticz-Thermostat-with-T-shift-and-OnOff-function

Simple thermostat for heatpump with two adjustments: Shift Target outlet temperature and On/Off function when Target outlet is at lowest value

Domoticz Thermostat with heatcurve-shift and OnOff function for Panasonic heatpump

Simple Domoticz DzVents thermostat for a Panasonic heatpump.

Prerequisits:

• You have setup the heatpump with a Heatcurve or direct temperature for the water outlet temperature. The built in thermostat of the Panasonic heatpump must be turned off.
• Script works in combination with the Domoticz HeishamonMQTT plugin and the HeishaMon communication PCB
• In Domoticz you have an accurate room temperature measurement available.

How does the script work?

The thermostat script works with two functions to control the room temperature:

1. Shift Heatcurve or change direct water outlet temperature--> When the room temperature gets above a setpoint (based on thermostat device with hysteresis) --> Shift(-1) Target outlet water temperature. It works also the other way around: Shift(+1) when it gets colder then the setpoint.

2. In most situations there is a minimum temperature of the water outlet at which the heatpump still functions well. In my situation (and therefor in the script) this minimum water outlet temperature is 26 degrees. If the water outlet temperature based on the heatcurve is 26 degrees and the room tmeprature gets above the setpoit we don't want it to shift the water outlet temperature below 26 degrees. Therefor the script uses a On/Off function to turn Off the heatpump when the water outlet temperature is at the minimum. When the room temperature gets below the setpoint, the heatpump is turned on again.

You can specify a hysteresis in various parts of the script. Adjust these to your own situation. I have a well-isolated house with only floorheating, therefor I have set very small hysteresis in the script.

Combination with Slowstart script

I have written a slowstart script to manage the Panasonic (monobloc) heatpump to a slow and efficient startup after restart and/or defrost. Because of this script the normal Shift function of the heatpump cannot be used and a manual T-shift device is being used. This thermostat script calls for this manual Shift device. If you don't use my slowstart script, fill in the IDX of the 'regular' Shift device. In Domoticz HeishamonMQTT plugin it is called: Z1_Heat_Request_Temp.