Zigbee Thermostatic Radiator Valve with Room Thermostat and HUB

Hi,
Until now I have been using the heating system of a European company. I have 4 TRVs (one for each radiator room) and the central house thermostat installed in the living room. This thermostat and the 4 trvs send temperature information by RF to the boiler hub located in another room and turn the heating on and off depending on the needs of each room. I could replace the radiator thermostats with the new zigbee ones, I could replace the central thermostat of living room with an other evelink thermostat but I don’t know about the boiler hub that gives the final command to the boiler to turn on and off what I could replace it with. It does not have to be an RF device. The new hub could be wifi or zigbee, and could operate with the trvs and the main theromstat with routines-scenes.
Thanks in advance

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TRV from SONOFF team is on the shelf now!
https://sonoff.tech/product/home-appliances/trvzb/ref/1/

Can you please give more details about it?

I mean, it just open/close the valve, but it will not communicate with the boiler (Nest Learning Thermostat) to turn it on/off. I’m understanding correctly?

By the way, your link is broken. You need to remove the /ref/1/ to works.

I will try to explain.
We have hot water in the pipes. Hot water is produced by an oil boiler. The old systems were without trvs. You turned on the boiler with a switch and the water circulated. If you felt hot, you turned off the boiler. In the early years we added room thermostats to turn the system on and off automatically. Later we added the thermostatic valves to each radiator to automatically open and close each radiator as we needed heat. That’s where we are today.

So I have a switch in the basement (HUB) that turns the burner on and off and receives an RF command from the main thermostat located in the living room of the house.
My quest is to replace the main living room thermostat and the switch located in the basement. The nest thermostats you mentioned are two in one. Thermostat and switch together in one device. I don’t want something like that because it’s not right to put the thermostat in the basement!

I think you can consider a temperature sensor and a smart switch for your solution.
You can create a smart scene in the eWeLink APP to achieve a thermostat function, for example,

IF the temp is 26 above, turn off the smart switch (control the ON/OFF of the boiler)
IF the temp is 20 below, turn on the smart switch

As for the temperature sensor, here are the options to choose.

As for the smart switch, it depends on your boiler power.

You also can consider the TH series product if you want to measure the temperature in the basement to turn off/on the boiler.

Hope this helps,

Thank you for your answer.

I was thinking about nspanel or nspanel pro and a pow switch plus three trvs.

What do you think ?

I have a similar system (but without the electronic TRVs yet) My system turns on the boiler using a sonoff at a predetermined time i select and I use a TH temperature reading to run a scene to turn the boiler off as it gets up to Maximum temperature (75c) and then on again when it gets to my minimum temp (60c) saves fuel and prevents the boiler from over heating (also have another independent controller as an overtemp). The TH directly controls the circulating pump. This gives me full control to turn the system on and off remotely even before i get home. plan is to get some sonoff TVRs to give better temp control in unused rooms etc. for even better fuel savings. The whole system is vey simple to setup and control with next to no input from me unless I want to.

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yes, with NSPanel or NSPanel Pro, you have the thermostat dashboard to control the temperature flexibly.
It is also a good solution for your case.

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You can set up a smart scene in eWeLink APP to trigger other smart devices.

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Thank you for your answer.

“To run a scene to turn off the boiler as it rises to its Maximum temperature (75C) and then turn it back on when it reaches my minimum temperature (60C)”

The boiler does this by itself. When you turn it on somehow, it always runs at those temperatures. When you turn it off, it stops heating the water.
I am interested in the internal thermostat of the house that will give commands to open and close based on the temperature of the house and not the water.
Let me explain the process a bit

  1. You turn on the switch on the thermostat (on-off) * and the boiler starts to heat up. the thermostat can be located anywhere
  2. You adjust the temperature of the room on the thermostat to the desired level, for example 22 degrees Celsius, and the boiler will work until the room reaches 22 degrees.
  3. When it reaches this temperature, it will send a new command to turn off the boiler and only the water circulator will continue to work until the water cools down.
  4. When you have smart electrostatic heads in addition to the central thermostat, they can also send a heating request when the room they are in has a lower temperature. In other words, these are also thermostats that can turn the boiler on and off.

*Specifically The switch sends a RF command to the farthest room where the systems HUB is located and the HUB sends the electric command with a cable to the boiler.

the thermostat panel in nspanel pro is not suitable for controlling the room temperature because it has hysteresis (±1*C)

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We will optimize the minimum temp accuracy to ±0.5*C in the next following APP update. Thanks for your feedback.

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This is very good news

Hi,
Simple question. can we manage the Sonoff thermostatic valve with an NS panel which has a temperature sensor it seems to me, all with Ihost? I would like to install this in my daughters’ room. Thank you for your answers. Sincerely

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I believe Theovac doesn’t care about the Hysteresis problem.
His Boiler is connected to the electric plug. Can the power of this plug be disconnected by some Sonoff device (or scene) once his thermostatic radiator valve registers the required temperature (i.e. +22C).
Could it be done by scene like this > IF TRVZB=+22C then turn off, Plug#4?

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Actually, if it is a gas boiler, then a dry contact relay should close if heat is needed and open when the desired temperature is achieved. But you’ve explained the base logic behind.

Unfortunately this is not possible with the TRVZB, because you can’t create a scene, where the TRVZB heating status is taken in account. I’ve also created a post here about this missing functionality.

The only workaround for now is to have a temperature sensor, which can act as a trigger. Which is kind of dumb, because, you trigger heating on a predefined temperature in the scene, not based on what the TRV is requesting. For example if you have the predefined temperature at 22C, you have 22C in the room, but for some reason you need 25C, if you turn the knob of the TRV, nothing will happen. To achieve 25C, you need to change the predefined temperature from the scene, from 22C to 25C.

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“…Unfortunately this is not possible with the TRVZB, because you can’t create a scene, where the TRVZB heating status is taken in account…”

Thank you Attila for your answer. You mean that TRVZB can not trigger and activate a scene to start-stop a boiler relay 220v ? It only opens and close the water ?
My existing system Drayton Wiser has TRVS and a sensor. I have install the TRVS at the rooms, the main sensor at the living room and the hub near the boiler switch. Each part (or room) can ask to the hub (and the boiler) for more temperature (to start stop the boiler I mean).

Yes, currently it kind of works only if i have hot water running in the pipes. It is just opening and closing the valve and since i don’t have permanent hot water in the pipes, sometimes they don’t even manage to bring up the temperature in the room to the desired one.
In one week of usage i had a lot of cases where the desired temperature was set at 23C and at 21C the radiators where still cold, TRV status was keeping, instead of heating, even if i had hot water in the pipes.

The only good side for now, is that each valve manage to prevent the room from massive overheating (meaning it does a max desired temperature +0.5C or +1C).

All the above, managed from the eWeLink app.
In the eWeLink web these devices are not even supported.

I am not sure how they work in Home Assistant since i don’t have any experience with this and neither the time to set this up.

I initially ordered 6 TRV’s and planned to order another 20, but for now, due to this kind of bad experience, i will put this project on hold.
There are too many missing features for now, like:

  • Set a limit for valve position. Let’s say, you have a radiator for which you would like to keep the valve always open, no matter the temperature reading. For example from the scale of 0-100% set manually to keep the valve 20% open, so the scale would become 20-100%, or you have a radiator, which you don’t want to use at full capacity then lower the 100% to 50%, so the scale would be 0-50%.

  • Power heat possibility. For example, for a predefined time (manually adjustable) open the valve to 100%, trigger a relay, regardless the temp reading.

  • Extending the log period, from 6 months to 1 year for standard users and for VIP, unlimited

  • Thermostat grouping:
    Beside controlling the grouped valves, it would be nice to have a graph of all grouped devices.
    Show the mean temperature of the grouped devices
    Possibility to create scene, like triggering a relay, if heat needed.
    Possibility to change desired temperature from one of the grouped device knob for the complete group, as an option

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excellent proposals… it would also be good to be able to connect an external thermometer (snzb-02 for example) to the TRVZB so we don’t even need to calibrate it.

It would also be interesting to connect an external thermometer to each TRVZB group (snzb-02 for example)

In my case it would be a really good solution.

I have 8 TRVZBs and a condominium boiler. The temperatures of the valves, despite being calibrated, drastically change the temperatures when they heat up and close before the rooms heat up.
With an external thermometer this problem would never happen.

The Sonoff thermostats are terrible, the temperature range of the ns panel and ns panel are unusable. We have been promised improvements which don’t materialise, take my advice and stick with the European stats that are superior!