SONOFF TRVZB - losing valve calibration quickly when using precise control

[adriannow]

Hello, I'm testing SONOFF TRVZB thermostatic radiator valve, and I was quite happy regarding precise control of valve opening (using valve opening/closing degree) in Versatile Thermostat. Just so everyone knows, by default Sonoff only opens valve to 0/100%, so it's going through some heavy cycles.

After initial testing everything looked fine, but then I noticed that the radiator is quite warm even after few hours when the valve should be 100% closed. So I've added additional thermometer directly on top of the radiator to see how it looks in reality:

(From the top: blue line is temperature directly on top of the radiator, yellow - set temperature (it was constant 23.5 degrees). And then looking at the second graph of the "Valve open percent", even after about 3 hours the radiator was still significantly hotter than the ambient temperature (measured less than meter away). So in short, valve was definitely not closed fully.

After I reinserted batteries and reset the TRVZB, it seems to recalibrate and close fully again. After about a day the problem started again.

I'll be trying to do some automation maybe to close fully and open the valve fully from time to time, to get the thermostat to recalibrate (as this is what it does after all on default firmware). But at this point I'm not sure if this will help - just my best guess.

[jmcollin78]

Hello @adriannow ,

Can you send us the configuration of your VTherm (see: https://github.com/jmcollin78/versatile_thermostat/blob/main/documentation/en/reference.md#custom-attributes)

[adriannow]

Sure, but from the initial observation, the VTherm is trying to manipulate the valve correctly - it may just be problem with the Sonoff TRVZB itself.

Here are my settings:

hvac_modes: off, auto, heat
min_temp: 7
max_temp: 35
target_temp_step: 0.5
current_temperature: 23.2
temperature: 23.5
hvac_action: off
is_on: true
hvac_mode: heat
preset_mode: none
type: null
is_controlled_by_central_mode: false
last_central_mode: null
frost_temp: 7
eco_temp: 7
boost_temp: 7
comfort_temp: 7
frost_away_temp: 0
eco_away_temp: 0
boost_away_temp: 0
comfort_away_temp: 0
target_temperature_step: 0.5
ext_current_temperature: -0.14
ac_mode: false
saved_preset_mode: none
saved_target_temp: 23.5
saved_hvac_mode: null
last_temperature_datetime: 2025-01-16T07:54:06.573695+01:00
last_ext_temperature_datetime: 2025-01-16T07:52:43.139986+01:00
minimal_activation_delay_sec: 10
total_energy: 0.61
last_update_datetime: 2025-01-16T07:54:06.574589+01:00
timezone: Europe/Warsaw
temperature_unit: °C
is_device_active: false
device_actives: 
nb_device_actives: 0
ema_temp: 23.16
is_used_by_central_boiler: false
temperature_slope: 0
hvac_off_reason: null
max_on_percent: null
have_valve_regulation: true
last_change_time_from_vtherm: 2025-01-16T07:53:31.040855+01:00
presence_sensor_entity_id: null
presence_state: unavailable
is_presence_configured: false
power_sensor_entity_id: null
max_power_sensor_entity_id: null
overpowering_state: unavailable
is_power_configured: false
device_power: 1
power_temp: null
current_power: null
current_max_power: null
mean_cycle_power: 0
motion_sensor_entity_id: null
motion_state: unavailable
is_motion_configured: false
motion_delay_sec: 0
motion_off_delay_sec: 0
motion_preset: null
no_motion_preset: null
window_state: unavailable
window_auto_state: unavailable
window_action: window_turn_off
is_window_bypass: false
window_sensor_entity_id: null
window_delay_sec: null
window_off_delay_sec: null
is_window_configured: false
is_window_auto_configured: false
window_auto_open_threshold: null
window_auto_close_threshold: null
window_auto_max_duration: null
is_safety_configured: true
safety_state: off
safety_delay_min: 60
safety_min_on_percent: 0.5
safety_default_on_percent: 0.1
is_auto_start_stop_configured: false
is_over_climate: true
start_hvac_action_date: null
underlying_entities: climate.sonoff_valve
is_regulated: true
regulated_target_temperature: null
auto_regulation_mode: auto_regulation_valve
regulation_accumulated_error: 0
auto_fan_mode: auto_fan_high
current_auto_fan_mode: auto_fan_high
auto_activated_fan_mode: null
auto_deactivated_fan_mode: null
auto_regulation_use_device_temp: false
follow_underlying_temp_change: false
friendly_name: sonoff-versa
supported_features: 401
preset_modes: none, frost, eco, comfort, boost
underlyings_valve_regulation: 
- - number.sonoff_valve_valve_opening_degree
  - number.sonoff_valve_valve_closing_degree
  - number.sonoff_valve_local_temperature_calibration

on_percent: 0
power_percent: 0
on_time_sec: 0
off_time_sec: 300
cycle_min: 5
function: tpi
tpi_coef_int: 0.6
tpi_coef_ext: 0.01
min_opening_degrees: 
valve_open_percent: 0
auto_regulation_dpercent: 0.05
auto_regulation_period_min: 5
last_calculation_timestamp: 2025-01-16T07:53:31.012130+01:00

[adriannow]

No problem, happy to share details as this is quite popular valve, and ability to control it precisely with VTherm would be perfect.

I understand if the closing degree is set, the hvac_action of the Sonoff climate was always False. Do you confirm this ?

It looks like this in my case (added red boxes to highlight hvac_action=heating, because orange fields are quite hard to see:

So hvac_action of the Sonoff climate is operating as normal - if the current temperature drops about 1 C degree below set point, it just starts hvac_action (regardless of the set valve opening/closing degree).

When max valve closing degree is set to 100% (default), it looks like this:

Important thing is to note here is that 2 values that are used for control: valve_opening_degree and valve_closing_degree are actually max_valve_opening_degree and max_valve_opening_degree (default both to 100%).

So when setting: valve_opening_degree: 50% and valve_closing_degree: 50% - Sonoff was actually opening the valve to 50%. It had no other option - VTherm was always narrowing it down to 1%, and had perfect control of valve opening percentage. In this case I didn't even looked at the hvac_action, as it actually was exactly what VTherm was displaying (everything other than 0% valve open was heating).

Now when you disable VTherm managing max_valve_closing_degree (leave it constantly to 100%), then Sonoff can choose to open the valve whenever it wants (as max close value is 100%). So it usually opens it only after big temperature drop and then closes for completely again - quite similar as default Sonoff working mode.

[adriannow]

FYI I am switching back to using max_valve_closing_degree controlled by VTherm - now with 10 min heating cycle (instead of 1 originally. Hopefully this will prevent de-regulation of Sonoff valve, as this was my only initial issue (after a while not being able to close valve fully).

With 1-min cycles VTherm was adjusting valve opening percent very frequently and I think this was something Sonoff didn't predicted.

[tbrasser]

I also use both max_opening and max_closing control on my trvzbs, everything seems fine:

hvac_modes:
  - "off"
  - auto
  - heat
min_temp: 15
max_temp: 25
target_temp_step: 0.1
preset_modes:
  - none
  - frost
  - eco
  - comfort
  - boost
  - activity
current_temperature: 19.8
temperature: 20
hvac_action: heating
preset_mode: activity
is_on: true
hvac_mode: heat
type: null
is_controlled_by_central_mode: true
last_central_mode: Auto
frost_temp: 15
eco_temp: 17
boost_temp: 21
comfort_temp: 20
frost_away_temp: 15
eco_away_temp: 15
boost_away_temp: 17
comfort_away_temp: 18
target_temperature_step: 0.1
ext_current_temperature: 0.2
ac_mode: false
saved_preset_mode: activity
saved_target_temp: 20
saved_hvac_mode: null
last_temperature_datetime: "2025-01-20T13:03:21.085008+01:00"
last_ext_temperature_datetime: "2025-01-20T12:59:41.706473+01:00"
minimal_activation_delay_sec: 5
total_energy: 0.64
last_update_datetime: "2025-01-20T13:05:25.665896+01:00"
timezone: Europe/Amsterdam
temperature_unit: °C
is_device_active: true
device_actives:
  - number.trv_eetkamer_links_valve_opening_degree
  - number.trv_eetkamer_rechts_valve_opening_degree
nb_device_actives: 2
ema_temp: 19.77
is_used_by_central_boiler: true
temperature_slope: -0.46
hvac_off_reason: null
max_on_percent: null
have_valve_regulation: true
last_change_time_from_vtherm: "2025-01-20T13:04:25.664817+01:00"
presence_sensor_entity_id: binary_sensor.magic_areas_presence_tracking_interior_area_state
presence_state: "on"
is_presence_configured: true
power_sensor_entity_id: null
max_power_sensor_entity_id: null
overpowering_state: unavailable
is_power_configured: false
device_power: 2
power_temp: null
current_power: null
current_max_power: null
mean_cycle_power: 2
motion_sensor_entity_id: binary_sensor.magic_areas_presence_tracking_eetkamer_area_state
motion_state: "on"
is_motion_configured: true
motion_delay_sec: 120
motion_off_delay_sec: 600
motion_preset: comfort
no_motion_preset: frost
window_state: unavailable
window_auto_state: unavailable
window_action: window_turn_off
is_window_bypass: false
window_sensor_entity_id: binary_sensor.magic_areas_aggregates_eetkamer_aggregate_door
window_delay_sec: null
window_off_delay_sec: null
is_window_configured: false
is_window_auto_configured: false
window_auto_open_threshold: null
window_auto_close_threshold: null
window_auto_max_duration: null
is_safety_configured: true
safety_state: "off"
safety_delay_min: 60
safety_min_on_percent: 0.5
safety_default_on_percent: 0.1
is_auto_start_stop_configured: false
is_over_climate: true
start_hvac_action_date: null
underlying_entities:
  - climate.trv_eetkamer_links
  - climate.trv_eetkamer_rechts
is_regulated: true
regulated_target_temperature: null
auto_regulation_mode: auto_regulation_valve
regulation_accumulated_error: 0
auto_fan_mode: auto_fan_none
current_auto_fan_mode: auto_fan_none
auto_activated_fan_mode: null
auto_deactivated_fan_mode: null
auto_regulation_use_device_temp: true
follow_underlying_temp_change: false
icon: phu:aqara-thermo-e1
friendly_name: Eetkamer
supported_features: 401
underlyings_valve_regulation:
  - - number.trv_eetkamer_links_valve_opening_degree
    - number.trv_eetkamer_links_valve_closing_degree
    - number.trv_eetkamer_links_local_temperature_calibration
  - - number.trv_eetkamer_rechts_valve_opening_degree
    - number.trv_eetkamer_rechts_valve_closing_degree
    - number.trv_eetkamer_rechts_local_temperature_calibration
on_percent: 1
power_percent: 100
on_time_sec: 60
off_time_sec: 0
cycle_min: 1
function: tpi
tpi_coef_int: 1
tpi_coef_ext: 0.04
min_opening_degrees: null
valve_open_percent: 100
auto_regulation_dpercent: 0.1
auto_regulation_period_min: 1
last_calculation_timestamp: "2025-01-20T12:55:14.777902+01:00"

[Riot2891]

Could you tell us which firmware version you are using? I'm currently on 1.2.1.

[tbrasser]

Same, also 1.2.1

[Riot2891]

I'm facing the same problem with nearly all of my TRVZBs. I'm in touch with Sonoff to figure out a solution. I had the impression that shifting arround the"max_valve_closing_degree" would make the TRVZB shift gradually from its calibration state. In my case i had to recalibrate the valves nearly every day.

I'm currently on 1 min heating cycles and will follow your suggestion and try out 10 minutes cycles to see if it does any good.

If that doesn't help my idea would be to use an additonal offset of -1°C on the temperature calibration, and just manipulate the "max_valve_opening_degree" and leave the "max_valve_closing_degree" at 100% .
To make this idea clearer: The TRVZBs are controlling the valves with one degree of hysteresis, meaning if you set the temperature to 20° they will open at 19.5° and close at 20.5°. Vtherm uses "local temperature calibration" to calibrate the "local temperature" value ot the TRVZB to the measurement of an external sensor. If we add -1° here the TRVZBs would alway try to heat because their local temperature would always be at least one degree lower than the setpoint. This way only the "max_valve_opening_degree" would be needed to control them.

It is not hte most elegant way but maybe worth a try if the 10 min cycle does not solve the problem.

[jmcollin78]

Hello, yes for valve 0.05 is really to low. The unit is a %. Like suggested please use 5.

[adriannow]

@jmcollin78 did that yesterday, it's working as you and @Riot2891 described 👍 .

[Riot2891]

I have my TRVZBs running with a 5% regulation threshold for nearly 24 hours and they are working fine so far. But we have to take into account that a 5% regulation threshold also leads to way less regulation cycles of the valve than 1%.
To stress one TRVZB even further I replicated your (@adriannow ) experiment and opened the valve to 100% then I went down in 5% increments until fully closed. I repeated this process 3 times, still the valve is functioning fine.
I will monitor the valves for a couple of more days. If everything is still fine I will try out 4% and so on to see how low we can go, as 5% gives me to mutch variance of the room temperature.
So far I haven't heatd anything new from Sonoff.

[adriannow]

@Riot2891 I'm on 3% for last 24h and it seems fine. On last calibration couple of days ago I remounted the TRVZB (a bit less tight) and noticed more closing steps in sensor.sonoff_valve_closing_steps, also sensor.sonoff_valve_idle_steps decreased.

[jmcollin78]

3% for last 24h and it seems fine

It sounds fine !

[adriannow]

Another thing I noticed in TRVZB - sometimes temperature adjustment based on external source is not updated for quite long time (probably not related to the calibration issue, but who knows).

On the screenshot orange line is external thermometer (temperature updated each 10 seconds). Most of the time it's ok-ish (visible on blue line, Sonoff temperature after adjustment). But for example on 12 PM I lowered target temperature, and VTherm was not adjusting TRVZB to external thermometer for about 2 hours.

Not sure if this is impacting anything, just an observation.

[Riot2891]

Interesting observation, but as you also mentioned I doubt it has anything to do with our calibration issue. As vtherm is shifting the closing and opening limit of the TRVZB it will function regardless of the state of the TRVZB. Therfore I would argue that calibrating the temperature of the TRVZB to the temperature reading of the external sensor is a nice feature but for valve regulation to function it is irrelevant.

[stephensalex]

I have noticed this issue with my Sonoff TRVZB this evening. I have a 10% (10) regulation threshold configured and valve closing degree at 100, valve opening degree at 0. Vtherm and trv showing as idle (not heating) but I could hear water flowing through and the radiator was hot. The valve has been installed for 10 days (it was also calibrated 10 days ago) and is on firmware 1.2.1. Setting the valve closing degree to 0 and then back to 100 resolved the issue.

[wildy]

So, should I still not use valve_closing_degree with my TVRZBs?

[jmcollin78]

https://github.com/jmcollin78/versatile_thermostat/blob/main/documentation/en/self-regulation.md#self-regulation-by-direct-valve-control

Note: for Sonoff TRVZB you should not configure the "closing degree" parameter. This leads to a bug in the TRV and the hvac_action is no more working.

[wildy]

So, still a bug, even in latest firmware (I'm running 1.2.1?)

So, right now I'm using direct valve control, with an external temp sensor and setting only opening degree. I have reset the closing degree to 0% and then 100% manually, to prevent any bugs from happening.

Is this the correct way to run it? I have noticed that the VTherm set my opening degree to just 14% for now, but apparently the temperature is maintained correctly.

[Riot2891]

@wildy @jmcollin78 from my obeservation and tests it is not "valve_closing_degree" that messes up the calibration of the valve. The problem are small vlave movements (<2%). If this happens you have to run the calibration process again.

@adriannow an I have tested this during the last days. I have one TRVZB working on 2% "regulation threshold" and 7 ohters on 3% for a 5 days now and they are working flawlessly. With 1% "regulation threshold" problems usually started to show within 24 hours.

I also can't confirm @adriannow hypothesis that short heating cycle would cause the problem. I'm on 1 minute hating cycles and facing now issues.

Therefore I recommend to just change "regulation threashold" to 3% and repeat the calibration process by removing one battery and pressing the knob. It would be great if you could report if this fixed your issues.