Hello there,
I bought some ITEAD Zigbee valves for my heaters, the idea is that each room could have different temperature thresholds and can be heated individually.
I am currently using a Tado thermostat (controlled by homeassistant via homekit) that turns on the boiler at a threshold heating the whole house, the boiler is activated using 2 wires and the tado is battery operated, and the temperature sensor is on the main tado (which is in the middle of the house)
Now, the logic that I want to achieve is that when there is at least one room scheduled to be heated it’s valve(s) should be open and the boiler turned on. and in reverse when all room are above their scheduled threshold the boiler must be turned off.
I thought of using a battery operated esp32 with a relay or a shelly (but I need to provide power)
do anyone here knows any other solution or have experience with something like this?
The boiler is a common gas heater which uses 2 wires to turn it on.
heater’s water temp is fixed (controller directly on the boiler) and currently is working via a tado thermostat that triggers the boiler based on temp thresold.
here:
the installation manual, mine is the default Relay setup
Esp32 is too hungry to be ideal battery operated solution. Shelly would be ideal, you could locate it where tado is now or directly under your boiler (for powering convenience). Shelly plus1 can be powered at 230VAC, 24-48VDC or 12VDC.
I wrote of batteries because I was thinking to place it where the tado currently is, where I get only relay cables.
But in case of a shelly I could place it directly in the Boiler box outside where I can get also power… also… if I use a shelly 1PM I could retain the old tado for manual override (by using the switch/relay connector) while testing the setup
And if your relay wires are in conduit, you can bring supply there quite easily. Battery powered devices are sometimes really practical, but I wouldn’t prefer them if I had power available.
And I am still trying to work out what your question actually is. Is it possible that you just need to turn the gas heater on and off with a simple HA switch, and do all the automation logic within HA?
What type of heating system is this? Radiant hydronic, fan-coil, steam, etc…?
If I’ve understood correctly, you’re saying the zone/room valves are what determine when heat is called for in that specific zone? If that’s the case, how do you set their desired zone temperature? Directly on the valve?
Are you wanting to eliminate the central thermostat as a temperature setting/controlling device, and just replace it with something that fires the boiler whenever a valve calls for heat? If the answer is yes, then I think the other suggestions of using Shellys at the valves and the boiler would work fine. Just make sure you check whether your boiler has any heat-up/cool-down or cycle length requirements (you can script the Shellys to handle that appropriately).
I’m also assuming that if a pump is part of the system, it is controlled by the boiler, since you mentioned only two wires to the boiler.
yup the gas boiler controls both heaters and (indipendently) water and is just a two wires relay, that heats and pump the water into the heaters.
Yes I want to remove the central all or nothing logic and move to a zones logic, with the temperature controlled by the valve or an external zigbee temperature sensor (which is already present in all rooms) so it seems a shelly is just fine (with optionally keeping the tado as an external switch, but that is another thought)
each room should have it’s own schedule and temp. threshold, and it starts with valve closed.
when valve hits schedule it should open and trigger the shelly
if another room needs heat it should only open it’s valve if the shelly is already triggered.
when the last valve closes the shelly should be turned off
(optional, using the tado as a manual trigger, it trtiggers the relay via cable and homeassistant should open all valves until temp is reached in its sensor, let’s call this legacy mode)
The setup is very common with traditional “non smart” heating system with two or more zones and thermostats. There thermostat opens a zone valve and an end switch sends signal to boiler. In your “smart” case individual thermostat opens one valve and HA is the switch. Only problem I can see in this setup is if the radiator valve doesn’t really open for some reason and HA commands the boiler on. Which eventually burns the circulation pump. This could be avoided if you leave one radiator valve fixed full open.