Temperature is not reached and fluctuates too much

[SgtGlattbart]

Hello everyone,
First of all, thank you very much for this addon, which I have been using for several months now.
I have a large heater in my living room with the Sonoff TRVZB and a few meters away is another heater with an old manual thermostat. I always have this one turned up to the maximum, as this heater hangs in line behind the living room heater. The thermometer hangs roughly in the middle between the two heaters.
Now I've always had the problem that the temperature is never maintained. In addition, the temperature has not been reached for about 3-4 weeks. I have to set the target temperature at least 0.5 C higher so that it is reached. Please find attached the configuration and a screenshot. I have also played with the values coef_int and coef_ext but without much improvement.

I also removed the addon incl. UI Card from HA two days ago and reinstalled/reconfigured it. That did not help.
In addition, I can no longer find the UI Card addon in the installable addons under HACS.

I have already clicked through many posts and tried the tips. It doesn't seem to help me.

hvac_modes:
  - "off"
  - auto
  - heat
min_temp: 7
max_temp: 35
target_temp_step: 0.1
preset_modes:
  - none
  - frost
  - eco
  - comfort
  - boost
current_temperature: 22
temperature: 23
hvac_action: heating
preset_mode: none
is_on: true
hvac_mode: heat
type: null
is_controlled_by_central_mode: true
last_central_mode: Heat only
frost_temp: 18
eco_temp: 21
boost_temp: 23
comfort_temp: 22.5
frost_away_temp: 0
eco_away_temp: 0
boost_away_temp: 0
comfort_away_temp: 0
target_temperature_step: 0.1
ext_current_temperature: 3.8
ac_mode: false
saved_preset_mode: none
saved_target_temp: 23
saved_hvac_mode: null
last_temperature_datetime: "2025-02-27T07:20:50.404827+01:00"
last_ext_temperature_datetime: "2025-02-27T06:03:20.961091+01:00"
minimal_activation_delay_sec: 10
minimal_deactivation_delay_sec: 0
total_energy: 12.78
last_update_datetime: "2025-02-27T07:20:50.405329+01:00"
timezone: Europe/Berlin
temperature_unit: °C
is_device_active: true
device_actives:
  - number.heizwz_valve_opening_degree
nb_device_actives: 1
ema_temp: 21.9
is_used_by_central_boiler: false
temperature_slope: 0.98
hvac_off_reason: manual
max_on_percent: null
have_valve_regulation: true
last_change_time_from_vtherm: "2025-02-27T07:17:40.612763+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: 0.79
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: 180
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: "2025-02-27T05:56:47.937790+01:00"
underlying_entities:
  - climate.heizwz
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: true
underlyings_valve_regulation:
  - - number.heizwz_valve_opening_degree
    - number.heizwz_local_temperature_calibration
on_percent: 0.79
power_percent: 79
on_time_sec: 237
off_time_sec: 62
cycle_min: 5
function: tpi
tpi_coef_int: 0.6
tpi_coef_ext: 0.01
min_opening_degrees: ""
valve_open_percent: 83
auto_regulation_dpercent: 5
auto_regulation_period_min: 5
last_calculation_timestamp: "2025-02-27T07:13:59.649132+01:00"
friendly_name: TRVWZ
supported_features: 401

[jmcollin78]

Hello can you please post me the regulation curves as described here: https://github.com/jmcollin78/versatile_thermostat/blob/main/documentation/en/additions.md#regulation-curves-with-plotly-to-fine-tune-your-thermostat

Zoom on many hours which the problem is evident.

[SgtGlattbart]

I am very curious to see what it could be.

[SgtGlattbart]

I would like to add a screenshot from last night. I hadn't changed the target temperature for most of the day, it was 22.5 °C

[jmcollin78]

Hello, this is not bad curves. You have stable period with power_percent under 0.3 which is good.

Power_percent is 0 (no heating) when the temperature is far above the target and starts to heat slowly when the temp decrease :

What makes the temperature increase with power_percent = 0 ? Do you have any other heat source ?

[jmcollin78]

I haven't seen before but you should now add the closing degree in the VTherm configuration. The issue that prevent to use the closing degree has been fixed. Then the Sonoff TRV should have no choice. I think it will help.

[SgtGlattbart]

I have found the problem for the temperature rise at night. I had set the thermometer to an indoor thermometer for my central gas heating. This sometimes seems to generate heat. I could only detect this by placing a second thermometer slightly away from it. I will then observe the next few days to see what the trend is now. I have added Closing_degree.