Perfect Heating Automation with Sonoff TRVZB

Configuration
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I upgraded my test one on z2m a few days ago, yes. But regarding ZHA sonoff’s page says that it’s up to HA team now:

We have already submitted the required review materials and are currently awaiting approval from the Home Assistant team. Once the review is approved, the update will be released. The exact timeline is subject to the approval process. Thank you for your patience and understanding.

So we’re waiting for HA guys…

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I have 4 Sonoff TRVZB and I have been experiemnting with different automations and controls for over a year (better thermostat, versatile thermostat, and more).
But what bugged me the most was the valve opening degree and a clear external sensor to base the heating from.

What has been working almost perfectly for me is the automation described in this thread, with PID controller.
I am now able to set the room temperature and there are minimal adjustments to the valve opening and closing (big bonus if you have one close to your bed like I do), and temperature are very stable.

The 2 additions I have done to the above thread is:

  • an automation to use the physical gear on the TRV to turn down and up the temperature if needed (mostly for the non tech persons in the house)
  • an automation to sync the calibration to the original climate TRV (this was mostly for debugging)

Happy to share if someone is interested

86

Hi everyone,

First of all, thanks a lot for this amazing tutorial and detailed overview – it’s really helpful and well explained! I’ve learned a lot about configuring the TRVZB, Better Thermostat, external sensors, and all the automations.

However, I’m surprised that controlling the central boiler isn’t discussed or integrated in Better Thermostat. In my setup, I have multiple TRVZBs in different rooms, but the boiler is still controlled by a single thermostat in one room. I’m curious how others handle this situation so that the boiler only runs when needed, instead of just staying on or cycling unnecessarily.

How have you all managed boiler control in multi-TRV setups? Is it usually handled with a relay/automation outside of Better Thermostat?

Thanks in advance!

Simon

87

This automation is focused on trv’s, which are intended for radiators. Boiler (generally) has it’s own electronics, which controls it’s temperature, better ones are outside and/or inside temperature dependant. During heating season it’s most effective that boiler is constantly on, only temperature varies (according to what i wrote above). Turning boiler completely off and on again only increases energy consumption.

88

Hi Protoncek,

I think I might not have explained myself clearly. My setup uses an instantaneous gas boiler, so there’s no hot water storage it heats on demand. That’s why I’m especially interested in coordinating the TRVs with the boiler to avoid unnecessary firing, since the boiler only runs when heat is actually needed.

I saw posts talking about creating binary sensors if trv is heating and regroup them into one to get global On/Off, i think will have to do it like that.

Thanks for your insights!

Simon

89

Aha… in that case i guess i’d do something you plan to do: like a conditional template sensor, which is “on” if at least one of trv’s is heating and off if none of them are heating .
something like this could be tested:

#(put into template.yaml)
binary_sensor:
  - name: gas heating sensor
    state: >
       {{ (states('sensor.switch.trv_1') == 'heating')
      or ( states('sensor.switch.trv_2') == 'heating')
      or  ( states('sensor.switch.trv_3') == 'heating')
  etc...
      }}

(edited - corrected)

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I received update to Z2M to support TRVZB fw 1.4.4 “Smart temperature control”
When I activated that the temperatures in each room started dropping dramatically. And I saw that each room’s TRV was “heating” but the radiator stayed cold and room temperatures kept dropping. I had to abandon the built-in PID after 24 hours as it started to get cold and I reverted back to working HA BT plugin and it’s centrally managed PID control which quickly brought the temperatures back to normal. It’s definitely promising progress that there would be built-in PID some day. But at this point without any debug info about the valve position etc. sudden 2 C drops in temperature without any sign of heating does not look that the technology is ready yet.

I tried to explain the bug also to ewelink forums but just got error “An error occurred: We’re sorry, but new users are temporarily limited to 0 replies in the same topic.” :smiley:

91

I think that basic thing that should be available is any kind of learning. PID must be calibrated to specific room…

92

I use a zigbee cold contact relay in parallel with the original thermostat control for our heating which is kept set to 16 degrees and only there for business continuity.

At the time I set it up I didn’t know much about template sensors so just have some fairly verbose automations. Some rooms can demand heat (valve is heating), some rooms are passive.

Thanks to this thread I have now all but eliminated the need for better thermostat which is how I did this all originally, I will soon start systematically removing it I have never liked that it is unreliable post HA restart and I am seeing very good results with the basic external temperature sensor feature. I note PID is coming and will give that a whirl when it appears in ZHA.

I graduated to automating the hot water as well using 3 Dallas temperature sensors and esphome for those. Relay in series with original hot water timer which is on permanent override and again still there for business continuity should HA be out. My relay has manual switch on it to override as well.

PS. lesson learned which I think is also above. I designed my external temperature updates to minimise writes to the valve but discovered you have to write a value at least once every 2h otherwise the valve will default back to internal temp sensor for frost safety reasons so factor this into your logic if needed. AI knows all about this feature of the value when you ask it (gemini etc).