I have a central heating system, driven by a simple thermostat at the entrance of the flat.
There are simple mechanic thermostatic valves in the main rooms.
Two of the room are in the south part of the home and three in the north.
There is a great difference in temperature from sout to north rooms.
When the thermostat cuts heating, the other rooms are not warm. I have to put a high temperature in the thermostat in order to keep the other rooms warm.
But then the temperature in southern rooms is too hisgh and it is difficult to adjust the mechanic thermostat valves in order to get a uniform temperature (and it depends in the difference of temperature from south to north that day).
That is why I am trying to replace of of it for a more versatile system.
But don’t want to install a comercial system that depends on cloud services.
Hestia Pi would be a good start point.
I can program it and measure temperature in thermostat room, in the south.
I plan to install another temperature (and humidity for the same price) sensor in a nothern room and keep heating working if one of the too sensors detects measures a low temperature.
But in order to optimize heating, I will need to control each radiator in each mean room.
To do that I need a thermostatic valve with wifi (or other protocol that I can connect to home net).
Are there any that can be used with openhab and HestiaPi?
Would HestiaPi be able to control that valves.
I suppose that it won’t do it by default, but it seems possible to change the openhab programming in order to get it working.
Would it be better to have a valve with a termostat included or justa a swithing valve and measure the temperature externally through other sensor?
It sounds like you have two problems to solve here: temperature sensing and controls.
Since you mentioned radiators, my first question is whether you have one loop for the entire home, or do you have 2 or 3 loops so each zone can be controlled independently? It sounds like there’s one thermostat, one loop, one zone, but I want to make sure I understand. I expect adding in more valves will be difficult, as there’s going to need to be a pair of them for each radiator to either bypass that radiator (radiator closed, bypass open), or go through the radiator (radiator open, bypass closed). My radiant heat system doesn’t have any bypass nor valves, the room-level control is based on whether the vents around the radiators are open or not.
I have a different problem that also requires remote temperature sensors. I already have the sensors (Ruuvi tags, which are also an open hardware design and uses open source software), and they transmit over Bluetooth. I do have a collector which jams them into a database, but I don’t want my thermostate to depend on that collector and the database being up. Instead, I plan on building a new HestiaPi with the Raspberry Pi Zero 2, which has bluetooth. Then the HestiPi can see the temperature itself and take action (e.g. turn on the heat) without being dependent on any other systems. So that’s going to be my solution for the temperature sensing side.
You are right, I have just one thermostat, one zone and just one relay to open or close heating to all my home (a flat). It is a central heating system for all the neighbourhood.
So I have to open or close the heating for all radiators at the same time.
Indeed my idea is to only close the relay when all temperatures indicate the temperature is above the setpoint and all the radiators are not needed.
The radiators are mounted in paralell so you can close one of them and the others continue to operate.
Some of them (in main rooms) have a thermostic valve already, but it is just a mechanic one so you cannot control it.
You can use an electronic valve with temperature and program included, and it would operate autonomously, but only if the heating relay is on.
Temperartures in back and front part of the flat are quite different.
The idea is to use a temperature sensor in living room, where the thermostat and relay is, and other in the back of the home.
When one of the measured temperatures are below threshold, relay should be on.
But the thermostatic valves in radiators should use their sensor to close or open, and control the room temperatures.
Another aproach is to read temperature and state from all valves and maintain the heating relay on as long as one of them is on.
I have bought an economic bluetooth valve to make some tests. You can program it, control temperature setpoint and program it.
But i would need an esp32 in order to control it through bluetooh.
Wifi valves are expensive and they consume much more power.
Ah, a key difference from my system! It makes much more sense now.
I imagine you’ll want to have the HestiaPi consider the temperature to be the minimum of your sensors and it’ll just trigger the relay to turn on the hear based on that. How to accomplish this will probably depend on the implementation of external sensors.
If you can get a Raspberry Pi Zero 2, you might be able to control the valves with that, as it has Bluetooth built in (assuming it’s possible to put the HestiaPi in Bluetooth range of all of the valves).
I’m not entirely sure how the programming will work for this, but I am interested to hear about whatever solution you come up with. My guess would be that you’d want to start by going into the Paper UI > Rules > “Heating/Cooling Check” and looking at the script in the “then…” section.
Well, I am not sure that there can be bluetooth connection from living room to back rooms.Too much distance, I think.
Wifi signal is weak and I have two routers with wifi (one is the ISP router used as gateway and wifi point and the other is a router with openWRT to configure internal net as I want).
My idea is to put a bridge (WIFI-bluetooth) in one of the back rooms that collects data from the bluetooth valves, using a ESP32 with a tasmota firmware that seems to be able to do the bluetooth conexion, I will equip it with a bme 280 sensor to collect temperature, humidity and preassure data.
In the living room there will be the controller (I think of using HestiaPi).
But I would need to alter the openhab programming somehow in order to maintain the relay opened whenever one of the rooms is below temperature threshold.
I would like the system to be more independent of the controller, so if there is some problem the valves continure to operate as programmed.
EQ3 N bluetooth valves have their own programming and temperature threshold, and a button to push if you want to operate manually.
So I need to know if HestiaPi is flexible enough to be able to change the programming of openhab.
A different solution would be to use another ESP32 with tasmota in the living room (it can control the relay too, and there is a thermostat addon) and an external openhab installation in my QNAP NAS in order to collect data and be able to easily reprogram and control everything.
I am trying to learn openhab now. For now I can control my LG TV set from openhab … nothing to do with heating control, but it was the only domotic system I have for now (compatible with openhab).
I will try to make proto boards and have a prototype system working.
The problem will be later to install it as an independent system with a nice box, battery and all the whistles.
Another problem I have is that I could not get HestiaPI working in my Pi Zero W.
I have installed it and enter in openhab configuration, but it keeps configuring first time use forever.
Being open source means you can change everything. The question is how much time you want to spend on this
I would expect the easiest it to do it through openHAB, create a group of sensors that publish on different MQTT topics (including the internal) and then configure the triggering temperature to start heating when the highest (MAX) sensor value goes below your target temp (the temperature set on the LCD/app) and to stop when even the MIN of the group reaches desired temp…
Richard (rlkoshak) has suggested this approach in the past.
Thank that is more or less what I am testing with openHab.
I have a EQ3 BL· valve. To access it from openHAB I have burned TASMOTA BLE to be able to control the valves. It is a gateway that publishes valve states through MQTT. I can use it to connect temperature sensors to measure temperatures in rooms.
My idea is to form a group with all the valve controls.
This valve integrate setpoint temperature and opearate independently (you can give them a program too and a night and day temperature) and by their status you can know if they are opened or closed.
As long as one is opened, the group would be on and the relay in thermostat on. When all are off, the relay can go to off.
May be temperatures measured by sensors should be take into accounto. But there wont be a sensor in each room for now, so may be one of the room is a bit more cold.
And rooms do not have to follow same schedule or setpoint, as when there is nobody in a room, it can stay in a night mode temperature.
I have to test it in real life, being able to take control and changes is great. I will read other aproches, thank you.
