It is probably a question already asked, but I could not find a specific answer for my problem.
I installed some Tuya thermostatic valves on my heaters, which communicate via zigbee with the bridge on which I patched the Tasmota firmware, connected to HASS.
The practical problem is that the temperature detected by the valve rises immediately when the heater switches on. For example, if I set the ignition value to 20 degrees, and the temperature drops from 20 to 19, the valve opens and the radiator starts to heat, but after 2 minutes the valve thermometer detects 24 degrees even if I still have 19 in the room, so it turns off the heater. Result: the temperature continues to drop, after a while I ahve 15 degrees with continuous ignitions of a few minutes, useless.
There is certainly the possibility of forcing the detected temperature, so yes I can set -5 so that the valve correctly detects the 19 degrees of the room, instead of 24. But then, while the room heats up, 24 degrees remain around the heater, the valve always detects 19 because it subtracts the correction value, and keeps it on until it’s REALLY 24 in the room.
It is not a problem with the valve, because considering where the heater is placed (behind the door, with the valve towards the inside of the niche) the temperature is really that, nearby.
So I bought a zigbee thermometer, so now I have to configure HASS. The ideal solution would be to send the valve the correction value to be set at the valve, subtracting the temperature detected by the valve from that detected by the thermometer.
For example, always assuming my desired temperature is 20 degrees:
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the temperature in the room drops to 19, the heater starts to heat up, the valve detects 24 but the temperature is still 19: fine, HASS sends them -5 (i.e. 19-24) so the valve correctly detects 19 and keeps the radiator on.
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the temperature in the room rises to 21, the valve again detects 24. This time HAAS sends them -3 (i.e. 21-24) which correctly shows the valve the temperature of 21, and so the valve closes the supply.
The problem is that I can’t find how to set the automation by sending the correction value to the valve when one of the two temperatures changes, does anyone know how to start me towards the solution? Thank you very much