Tuya WiFi Smart TRV: underlying_current_temperature sometimes doesn't get updated after syncing room temperature to underlying climate

[AndreasUfert]

Version of the custom_component

8.5.1

Configuration

My VTherm attributes are the following:

hvac_modes:
  - "off"
  - heat
  - cool
min_temp: 7
max_temp: 35
target_temp_step: 0.5
preset_modes:
  - none
  - frost
  - eco
  - comfort
  - boost
current_temperature: 15.9
temperature: 15
hvac_action: idle
preset_mode: none
hvac_mode: heat_cool
ema_temp: 15.94
specific_states:
  is_on: true
  last_central_mode: null
  last_update_datetime: "2026-01-12T11:30:28.011369+01:00"
  ext_current_temperature: -5.5
  last_temperature_datetime: "2026-01-12T11:28:27.999369+01:00"
  last_ext_temperature_datetime: "2026-01-12T11:28:27.917742+01:00"
  is_device_active: false
  device_actives: []
  nb_device_actives: 0
  ema_temp: 15.94
  temperature_slope: -0.12
  hvac_off_reason: null
  total_energy: 0
  last_change_time_from_vtherm: "2026-01-12T06:22:24.615358+01:00"
  messages: []
  is_sleeping: false
  is_locked: false
  is_recalculate_scheduled: true
configuration:
  ac_mode: false
  type: over_climate
  is_controlled_by_central_mode: true
  target_temperature_step: 0.5
  timezone: Europe/Berlin
  temperature_unit: °C
  is_used_by_central_boiler: false
  max_on_percent: null
  have_valve_regulation: false
  cycle_min: 5
preset_temperatures:
  frost_temp: 7
  eco_temp: 19
  boost_temp: 30
  comfort_temp: 21
  frost_away_temp: 0
  eco_away_temp: 0
  boost_away_temp: 0
  comfort_away_temp: 0
current_state:
  hvac_mode: heat_cool
  target_temperature: 15
  preset: none
requested_state:
  hvac_mode: heat_cool
  target_temperature: 15
  preset: none
is_presence_configured: false
is_power_configured: false
power_manager:
  device_power: 1
  mean_cycle_power: 0
is_motion_configured: false
is_window_configured: true
is_window_auto_configured: false
window_manager:
  window_state: "off"
  window_auto_state: unavailable
  window_action: window_frost_temp
  is_window_bypass: false
  window_sensor_entity_id: binary_sensor.contact_sensor_6_door
  window_delay_sec: 10
  window_off_delay_sec: 10
  window_auto_open_threshold: 3
  window_auto_close_threshold: 0
  window_auto_max_duration: 30
is_safety_configured: true
safety_manager:
  safety_state: "off"
  safety_delay_min: 60
  safety_min_on_percent: 0.5
  safety_default_on_percent: 0.1
is_lock_configured: true
lock_manager:
  is_locked: false
  lock_users: true
  lock_automations: true
  lock_code: false
timed_preset_manager:
  is_active: false
  preset: null
  end_time: null
  remaining_time_min: 0
is_heating_failure_detection_configured: false
is_auto_start_stop_configured: false
is_over_climate: true
regulation_accumulated_error: 0
regulated_target_temperature: 15
vtherm_over_climate:
  start_hvac_action_date: null
  last_mean_power_cycle: 0
  underlying_entities:
    - climate.heizthermostat_gastezimmer
  is_regulated: false
  auto_fan_mode: auto_fan_none
  current_auto_fan_mode: auto_fan_none
  auto_activated_fan_mode: null
  auto_deactivated_fan_mode: null
  follow_underlying_temp_change: false
  auto_regulation_use_device_temp: false
  temp_synchronisation:
    sync_entity_ids:
      - number.heizthermostat_gastezimmer_temperature_correction
    sync_with_calibration: true
    sync_attributes:
      number.heizthermostat_gastezimmer_temperature_correction:
        value: 8.2
        min_sync_entity: -10
        max_sync_entity: 10
        step_sync_entity: 0.1
friendly_name: Gästezimmer VT
supported_features: 401

If it is releveant to regulation performance or optimisation some curves are needed

To have a great curves demonstrating what you think is a problem, please install and configure what is described here: Even better with Plotly to tune your Thermostat

Describe the bug

I'm syncing my room temperature to the underlying TRV using the "Synchronize device temperature" feature. This works for some time (multiple hours), but at some point the VTherm's internal value for the "current_temperature" attribute of the underlying state isn't updated anymore. That leads to the offset (temperature_correction) running away as the same offset is added over and over again.

In the logs one can see the immediate events after increasing the offset being ignored ("a underlying state change event is received but no real change have been found. Forget the event"), but I think the _async_climate_changed handler should look for changes in the current_temperature attribute.

I haven't figured out what's different during the first hours when everything works fine but I added the logs and a screenshot when the offset is running away.

I'm trying to:
Use the "Synchronize device temperature"

And I expect:
The underlying's local temperature more or less reflect the room temperature

But I observe this:
The underlying's correction offset is increased until it reaches its maximum value

I read the documentation on the README.md and specially the Troubleshooting page and I don't find any relevant information about this issue.

Debug log

2026-01-12 11:43:29.530 INFO (MainThread) [custom_components.versatile_thermostat.base_thermostat] --------------------> NEW EVENT: VersatileThermostat-Gästezimmer VT - Temperature changed to state 15.8817043304443 --------------------------------------------------------------
2026-01-12 11:43:29.530 DEBUG (MainThread) [custom_components.versatile_thermostat.ema] EMA-Gästezimmer VT - timestamp=2026-01-12 11:43:29.527138+01:00 alpha=0.50 measurement=15.88 current_ema=15.90 new_ema=15.90
2026-01-12 11:43:29.530 DEBUG (MainThread) [custom_components.versatile_thermostat.base_thermostat] VersatileThermostat-Gästezimmer VT - After setting _last_temperature_measure 2026-01-12 11:43:29.527138+01:00, state.last_changed.replace=2026-01-12 11:43:29.527138+01:00
2026-01-12 11:43:29.530 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_window_manager] WindowManager-Gästezimmer VT - Window auto is on, check the alert. last slope is -0.120
2026-01-12 11:43:29.530 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_window_manager] WindowManager-Gästezimmer VT - Window auto event is ignored because bypass is ON or window auto detection is disabled
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_safety_manager] SafetyManager-Gästezimmer VT - checking safety delta_temp=0.0 delta_ext_temp=1.0 mod_cond=True temp_cond=False climate_cond=False switch_cond=False
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_auto_start_stop_manager] AutoStartStopManager-Gästezimmer VT - auto start/stop is disabled (or not configured)
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_auto_start_stop_manager] AutoStartStopManager-Gästezimmer VT - auto start/stop is disabled (or not configured)
2026-01-12 11:43:29.531 INFO (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - Calling ThermostatClimate._send_regulated_temperature force=False
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - period (5.0) min is >= 5 min -> auto-regulation is available
2026-01-12 11:43:29.531 INFO (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - regulation calculation will be done
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - usage regulation_step: 0.20 
2026-01-12 11:43:29.531 INFO (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - Regulated temp have changed to 15.0. Resend it to underlyings
2026-01-12 11:43:29.531 INFO (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - dtemp (0.0) is < 0.2 -> forget the regulation send for climate.heizthermostat_gastezimmer
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.base_thermostat] VersatileThermostat-Gästezimmer VT - Checking new cycle. hvac_mode=heat_cool, safety_state=off, preset_mode=none, force=False
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_window_manager] WindowManager-Gästezimmer VT - Window auto is on, check the alert. last slope is -0.120
2026-01-12 11:43:29.531 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_window_manager] WindowManager-Gästezimmer VT - Window auto event is ignored because bypass is ON or window auto detection is disabled
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.feature_heating_failure_detection_manager] HeatingFailureDetectionManager-Gästezimmer VT - heating failure detection is disabled (or not configured)
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.532 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - Calling update_custom_attributes: {'hvac_action': <HVACAction.IDLE: 'idle'>, 'hvac_mode': <HVACMode.HEAT_COOL: 'heat_cool'>, 'preset_mode': 'none', 'ema_temp': 15.9, 'specific_states': {'is_on': True, 'last_central_mode': None, 'last_update_datetime': '2026-01-12T11:43:29.532296+01:00', 'ext_current_temperature': -5.2, 'last_temperature_datetime': '2026-01-12T11:43:29.527138+01:00', 'last_ext_temperature_datetime': '2026-01-12T11:42:29.921302+01:00', 'is_device_active': False, 'device_actives': [], 'nb_device_actives': 0, 'ema_temp': 15.9, 'temperature_slope': -0.12, 'hvac_off_reason': None, 'total_energy': 0, 'last_change_time_from_vtherm': '2026-01-12T06:22:24.615358+01:00', 'messages': [], 'is_sleeping': False, 'is_locked': False, 'is_recalculate_scheduled': False}, 'configuration': {'ac_mode': False, 'type': 'over_climate', 'is_controlled_by_central_mode': True, 'target_temperature_step': 0.5, 'timezone': 'Europe/Berlin', 'temperature_unit': <UnitOfTemperature.CELSIUS: '°C'>, 'is_used_by_central_boiler': False, 'max_on_percent': None, 'have_valve_regulation': False, 'cycle_min': 5.0}, 'preset_temperatures': {'frost_temp': 7.0, 'eco_temp': 19.0, 'boost_temp': 30.0, 'comfort_temp': 21.0, 'frost_away_temp': 0, 'eco_away_temp': 0, 'boost_away_temp': 0, 'comfort_away_temp': 0}, 'current_state': {'hvac_mode': 'heat_cool', 'target_temperature': 15.0, 'preset': 'none'}, 'requested_state': {'hvac_mode': 'heat_cool', 'target_temperature': 15.0, 'preset': 'none'}, 'is_presence_configured': False, 'is_power_configured': False, 'power_manager': {'device_power': 1.0, 'mean_cycle_power': 0.0}, 'is_motion_configured': False, 'is_window_configured': True, 'is_window_auto_configured': False, 'window_manager': {'window_state': 'off', 'window_auto_state': 'unavailable', 'window_action': 'window_frost_temp', 'is_window_bypass': False, 'window_sensor_entity_id': 'binary_sensor.contact_sensor_6_door', 'window_delay_sec': 10, 'window_off_delay_sec': 10, 'window_auto_open_threshold': 3.0, 'window_auto_close_threshold': 0.0, 'window_auto_max_duration': 30}, 'is_safety_configured': True, 'safety_manager': {'safety_state': 'off', 'safety_delay_min': 60, 'safety_min_on_percent': 0.5, 'safety_default_on_percent': 0.1}, 'is_lock_configured': True, 'lock_manager': {'is_locked': False, 'lock_users': True, 'lock_automations': True, 'lock_code': False}, 'timed_preset_manager': {'is_active': False, 'preset': None, 'end_time': None, 'remaining_time_min': 0}, 'is_heating_failure_detection_configured': False, 'is_auto_start_stop_configured': False, 'is_over_climate': True, 'regulation_accumulated_error': 0, 'regulated_target_temperature': 15.0, 'vtherm_over_climate': {'start_hvac_action_date': None, 'last_mean_power_cycle': 0.0, 'underlying_entities': ['climate.heizthermostat_gastezimmer'], 'is_regulated': False, 'auto_fan_mode': 'auto_fan_none', 'current_auto_fan_mode': 'auto_fan_none', 'auto_activated_fan_mode': None, 'auto_deactivated_fan_mode': None, 'follow_underlying_temp_change': False, 'auto_regulation_use_device_temp': False, 'temp_synchronisation': {'sync_entity_ids': ['number.heizthermostat_gastezimmer_temperature_correction'], 'sync_with_calibration': True, 'sync_attributes': {'number.heizthermostat_gastezimmer_temperature_correction': {'value': 8.6, 'min_sync_entity': -10.0, 'max_sync_entity': 10.0, 'step_sync_entity': 0.1}}}}}
2026-01-12 11:43:29.534 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - incremente_energy incremented energy is 0
2026-01-12 11:43:29.534 DEBUG (MainThread) [custom_components.versatile_thermostat.underlyings] VersatileThermostat-Gästezimmer VT-climate.heizthermostat_gastezimmer - hvac_action simulation target=15.0, current=15.7, hvac_mode=heat_cool
2026-01-12 11:43:29.534 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - added energy is 0.000 . Total energy is now: 0.000
2026-01-12 11:43:29.534 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - Synchronize device temperature for entity number.heizthermostat_gastezimmer_temperature_correction: local_temp=15.70, room_temp=15.88, current_offset=8.60 -> new offset=8.80
2026-01-12 11:43:30.889 INFO (MainThread) [custom_components.versatile_thermostat.thermostat_climate] --------------------> NEW EVENT: VersatileThermostat-Gästezimmer VT - Underlying climate state changed from <state climate.heizthermostat_gastezimmer=heat_cool; hvac_modes=[<HVACMode.OFF: 'off'>, <HVACMode.HEAT_COOL: 'heat_cool'>, <HVACMode.HEAT_COOL: 'heat_cool'>], min_temp=5.0, max_temp=35.0, target_temp_step=0.5, preset_modes=['eco'], current_temperature=26.2, temperature=15.0, preset_mode=None, friendly_name=Heizthermostat Gästezimmer, supported_features=17 @ 2026-01-12T07:26:37.667025+01:00> to new_state <state climate.heizthermostat_gastezimmer=heat_cool; hvac_modes=[<HVACMode.OFF: 'off'>, <HVACMode.HEAT_COOL: 'heat_cool'>, <HVACMode.HEAT_COOL: 'heat_cool'>], min_temp=5.0, max_temp=35.0, target_temp_step=0.5, preset_modes=['eco'], current_temperature=26.4, temperature=15.0, preset_mode=None, friendly_name=Heizthermostat Gästezimmer, supported_features=17 @ 2026-01-12T07:26:37.667025+01:00> --------------------------------------------------------------
2026-01-12 11:43:30.889 DEBUG (MainThread) [custom_components.versatile_thermostat.thermostat_climate] VersatileThermostat-Gästezimmer VT - a underlying state change event is received but no real change have been found. Forget the event

Full log is added as an attachment

x_home-assistant_versatile_thermostat_2026-01-12T10-50-40.528Z.log

Screenshot of history of relevant entities for the logging period

[jmcollin78]

Hello,

Thank you for your complete report.
I have two question before deep diving in the informations you gave:

1. what is your TRV ? Is that a Sonoff TRVB or other one ?
2. Is that a new issue since the update of VTherm ? Or is that the first time you test it ?

Calibration Offset has been developped with Sonoff TRVZB and works fine for this kind of VTherm. What can happens, is that the local_temp (the temperature named current_temperature of the underlying climate don't take into account the current calibration offset. Can you please check that ? To test this, change the calibration offset manually and check if the current_temperature is changed. It should. current_temp = interna_temp + calibration offset.

If you can set directly an external temperature in your TRV, i advice to use it.

[AndreasUfert]

1. The TRV is a Tuya WiFi Smart TRV. Tinytuya lists these details: "product_name": "WiFi Smart TRV", "product_id": "mzag8tu06ad4nxsn"
2. Unfortunately it's the first time I test it. But I'm open for downgrading it for some days to a version below 8.5.1 if you want me to test some things.

Regarding your question whether current_temperature gets corrected when I externally change the offset: Yes. I'll attach a screenshot. Actually it's the zoomed-out version of the screenshot I attached earlier. The first drop in offset and current_temperature was setting the offset to 0.0° in the Tuya app. The second one was reloading the Versatile Thermostat integration for this VTherm. Since then no new "running away" happened, but I have seen this on two other VTherms similarily yesterday. There're some particular cirumstances that make the problem start - like today around 7:40 in my screenshot. Unfortunately I have no logs of this moment. But I have activated debug logging now so I will have logs as soon as the problem returns.

[AndreasUfert]

This time I caught it in the logs. Same as yesterday: It worked all night, keeping the actual temperature close to the target temperature and only making small adjustments to the correction offset.

Then, at around 6:15/6:30 the window was opened and closed. Shortly after that the new target of 15° was reached and the valve closed.

What followed was adjusting the correction offset as the TRV's internal temperature wasn't influenced by warm water as much as when the valve was open. And at around 8:45 the adjusting process ran away again. The logs, however, show two things:

• local_temp is changing as the temperature and the offset interact. It then stops: The last change in local_temp was at 2026-01-13 08:35:28.268, since then local_temp is tuck at 16.9°C, leading to the continuously increased offset.
• However, current_temperature as reported by the underlying TRV rises with every increased offset (from 17.0°C at 8:35 to 22.9°C at 10:00). These events are ignored by _async_climate_changed ("a underlying state change event is received but no real change have been found. Forget the event")

vt.log

[AndreasUfert]

Addendum: After reloading the integration (just like yesterday) the calibration works again without any problems.

[AndreasUfert]

Addendum 2: Two other VTherms operation three underlying TRVs went off at almost the same time as the one above: All corrections offsets started running away between 08:30 and 09:15 today. I haven't reloaded them yet.

[jmcollin78]

Hello, I will turn this into a discussion because it is not an issue related to VTherm. Your "Tuya WiFi Smart TRV" just don't work if I understand well.

[AndreasUfert]

What makes you believe that? For me it's hard to tell but from what I see the devices actually change their internal temperature value as the offset is being increased. Is it that they don't return the value to the VTherm's callback function at some point? After some event?

If I look at the period of time in question it does actually look as if the Tuya devices disappeared shortly (at least the window sensors). And after that event at 08:33 the problem started:

fulllog.txt