I want to share my room temperature control system, it was developed by me back in 2021, it is currently working and being improved.
Introduction
I will tell you the basic conditions for two rooms so as not to burden the story. If you understand up to two, then it will be clear further.
So, we have two rooms where there is an electric valve on the battery controlled by the Aqara smart relay, which in turn receives information from the Aqara temperature sensors.
You ask why I don’t have TVR Aqara (I have 4 of them), I have to disappoint you, it is very, very difficult for individual boilers, there are serious drawbacks. I hope the new version of TVR Aqara will take these drawbacks into account.
Sorry for the lyrical digression, let’s continue.
We set requirements for temperature control in two independent rooms (hereinafter room 1, room 2), if room 1 and room 2 have a temperature above the set point (automation), then turn off the heating boiler.
I also add one temperature sensor directly to the battery return line, I do this to turn off the battery in advance when it has heated up to a certain temperature. I explain that turning off the heating in time does not lead to overheating of the room. As in practice, the room sensor is somewhere near the door, the battery heats up and the room temperature sensor is triggered with a delay, the battery turns off, but due to severe overheating, the temperature becomes several degrees higher than the set one.
Now the heating boiler, it has standard terminals for dry contacts (thermostat), we connect these wires to the dry contacts of the AqaraT2 relay (once I had to make an intermediate relay), thank God Aqara released a gorgeous relay with dry contacts.
Solving the problem.
We create automation in the directions of room 1(2).
First task: On room 1(2) at T°C<22.
Second task: Off room 1(2) at T°C>22.
Third task: Off the battery that overheated in room 1(2) at T°C>41 (I did 41 degrees experimentally).
Fourth task: make the boiler control depending on the heating needs of rooms 1(2).
Creating automations.
First task. On heating.
IF (do everything)
- T°C<22. (Sensor room 1(2))
- T°C<30 (sensor on the battery, this condition <30 means that the battery is cooled, ready for heating).
- relay Off (relay controls the room 1(2) thermostat).
THEN - On relay (relay controls the room 1(2) thermostat).
Second task: Off by room 1(2) temperature sensor
IF
- T°C>22. (Sensor room 1 (2))
- relay On (relay controls room 1(2) thermovalve).
THEN - relay Off (relay controls room 1(2) thermovalve).
The third task. Off when the battery in room 1(2) overheats, the sensor on the battery.
IF (do everything)
- T°C>41 (sensor on the battery, this condition >41 means that the battery is very hot).
- relay On (relay controls room 1(2) thermovalve).
THEN - relay Off (relay controls room 1(2) thermovalve).
And finally, the fourth task. Boiler control, there will be two automations for On and Off of the boiler.
On heating boiler
IF (do anything)
- room relay (1) On
- room relay (2) On
THEN - On relay T2 (relay for the boiler)
Off heating boiler
IF (do everything)
- room relay (1) Off
- room relay (2) Off
- relay T2 On (relay for the boiler)
THEN - Off relay T2 (relay for the boiler)
Explanation, in this automation in the IF section I turned on the T2 relay to exclude (disable) turning on the boiler when the batteries in the rooms are closed.
There is another important detail in this control scheme, there must be at least one battery in the house that is never blocked. This is for the safe operation of the boiler (circulation pump).
I only superficially described the control algorithm, in fact it is quite complicated for me. The algorithm has a condition “if I entered the room and turned on the TV, then turn on the additional heating.” There are also conditions with day, night, security, spring, summer…
This is my little story, if anyone is interested, ask, I will be happy to tell you.
Thank you for taking the time to read it.