Auto TPI behaviour investigation

[eflye-veepeetech]

Hello everyone,
I applied AutoTPI on all my Vhterm when the feature was deployed, probably a bit mad but this is a very valuable feature in my opinion.

i would to share here one behaviour that i have difficulty to understand

First of all find below current Vtherm and auto_tpi conf for this room:

sensor.salon_vthermostat_auto_tpi_learning_state:

coeff_int_cycles: 17
coeff_ext_cycles: 155
heating_cycles_count: 608
thermal_time_constant_hours: 13.3
model_confidence: 0.67
last_learning_status: learned_indoor_heat
learning_start_dt: "2026-01-27T14:14:30.617839+01:00"
allow_kint_boost_on_stagnation: true
allow_kext_compensation_on_overshoot: true
bootstrap_failure_count: 0
max_capacity_heat: 0.8640281457246608
capacity_heat_status: learned
capacity_heat_value: 0.8640281457246608
capacity_heat_count: 5
calculated_coef_int: 0.07520694540809986
calculated_coef_ext: 0.006098097985924204
icon: mdi:brain
friendly_name: Salon - Vthermostat Auto TPI Learning State

climate.salon_vthermostat:

hvac_modes:
  - heat
  - sleep
  - "off"
min_temp: 7
max_temp: 35
target_temp_step: 0.1
preset_modes:
  - none
  - frost
  - eco
  - comfort
  - boost
current_temperature: 18.6
temperature: 20
hvac_action: heating
preset_mode: none
hvac_mode: heat
ema_temp: 18.53
specific_states:
  is_on: true
  last_central_mode: Auto
  last_update_datetime: "2026-01-29T17:07:08.672470+01:00"
  ext_current_temperature: 4.3
  last_temperature_datetime: "2026-01-29T16:54:03.543565+01:00"
  last_ext_temperature_datetime: "2026-01-29T16:18:15.883818+01:00"
  is_device_active: true
  device_actives:
    - number.salon_radiateur_cour_valve_opening_degree
    - number.salon_radiateur_baie_vitree_valve_opening_degree
    - number.salon_radiateur_fenetre_sente_valve_opening_degree
  nb_device_actives: 3
  ema_temp: 18.53
  temperature_slope: 0.08
  hvac_off_reason: null
  total_energy: 110429.99
  last_change_time_from_vtherm: "2026-01-29T17:07:08.672109+01:00"
  messages: []
  is_sleeping: false
  is_locked: false
  is_recalculate_scheduled: false
  auto_tpi_state: "on"
  auto_tpi_learning:
    coeff_indoor_heat: 0.07520694540809986
    coeff_outdoor_heat: 0.006098097985924204
    coeff_indoor_autolearn: 18
    coeff_outdoor_autolearn: 155
    max_capacity_heat: 0.8640281457246608
    offset: 0
    last_power: 0.2
    last_order: 20.000000000000014
    last_temp_in: 18.63
    last_temp_out: 4.3
    last_state: heat
    previous_state: heat
    last_on_temp_in: 18.63
    last_update_date: "2026-01-29T17:03:07.947790+01:00"
    last_heater_stop_time: "2026-01-29T17:03:07.942064+01:00"
    cycle_start_date: "2026-01-29T17:03:07.947790+01:00"
    cycle_active: true
    current_cycle_cold_factor: 0.000004771666666666667
    current_cycle_params:
      on_time_sec: 59
      off_time_sec: 240
      on_percent: 0.2
      hvac_mode: heat
    consecutive_failures: 0
    autolearn_enabled: true
    last_learning_status: gap_too_large_for_outdoor(gap=1.37 > 1.0)
    total_cycles: 609
    consecutive_boosts: 0
    regime_change_detected: false
    learning_start_date: "2026-01-27T14:14:30.617839+01:00"
    capacity_heat_learn_count: 5
    bootstrap_failure_count: 0
    allow_kint_boost: true
    allow_kext_overshoot: true
configuration:
  ac_mode: false
  type: over_climate_valve
  is_controlled_by_central_mode: true
  target_temperature_step: 0.1
  timezone: Europe/Paris
  temperature_unit: °C
  is_used_by_central_boiler: true
  max_on_percent: null
  have_valve_regulation: true
  cycle_min: 5
  minimal_activation_delay_sec: 10
  minimal_deactivation_delay_sec: 0
preset_temperatures:
  frost_temp: 7
  eco_temp: 17
  boost_temp: 21
  comfort_temp: 19
  frost_away_temp: 0
  eco_away_temp: 0
  boost_away_temp: 0
  comfort_away_temp: 0
current_state:
  hvac_mode: heat
  target_temperature: 20.000000000000014
  preset: none
requested_state:
  hvac_mode: heat
  target_temperature: 20.000000000000014
  preset: none
is_presence_configured: false
is_power_configured: false
power_manager:
  device_power: 8784
  mean_cycle_power: 1756.8
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_turn_off
  is_window_bypass: false
  window_sensor_entity_id: binary_sensor.salon_baie_vitree_contact
  window_delay_sec: 30
  window_off_delay_sec: 30
  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
  safety_default_on_percent: 0
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: true
heating_failure_detection_manager:
  heating_failure_state: "off"
  cooling_failure_state: "off"
  heating_failure_threshold: 0.9
  cooling_failure_threshold: 0
  detection_delay_min: 15
  temperature_change_tolerance: 0.5
  failure_detection_enable_template: null
  is_detection_enabled_by_template: true
  heating_tracking:
    is_tracking: false
    initial_temperature: null
    current_temperature: null
    remaining_time_min: null
    elapsed_time_min: null
  cooling_tracking:
    is_tracking: false
    initial_temperature: null
    current_temperature: null
    remaining_time_min: null
    elapsed_time_min: null
is_auto_start_stop_configured: false
fan_mode: null
fan_modes: []
is_over_climate: true
regulation_accumulated_error: 0
regulated_target_temperature: null
vtherm_over_climate:
  start_hvac_action_date: "2026-01-29T17:02:08.673392+01:00"
  last_mean_power_cycle: 1756.8
  underlying_entities:
    - climate.salon_radiateur_cour
    - climate.salon_radiateur_baie_vitree
    - climate.salon_radiateur_fenetre_sente
  is_regulated: true
  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
  regulation:
    regulated_target_temperature: null
    auto_regulation_mode: auto_regulation_valve
    regulation_accumulated_error: 0
  temp_synchronisation:
    sync_entity_ids:
      - number.salon_radiateur_cour_external_temperature_input
      - number.salon_radiateur_baie_vitree_external_temperature_input
      - number.salon_radiateur_fenetre_sente_external_temperature_input
    sync_with_calibration: false
    sync_attributes:
      number.salon_radiateur_cour_external_temperature_input:
        value: 18.6
        min_sync_entity: 0
        max_sync_entity: 99.9
        step_sync_entity: 0.1
      number.salon_radiateur_baie_vitree_external_temperature_input:
        value: 18.6
        min_sync_entity: 0
        max_sync_entity: 99.9
        step_sync_entity: 0.1
      number.salon_radiateur_fenetre_sente_external_temperature_input:
        value: 18.6
        min_sync_entity: 0
        max_sync_entity: 99.9
        step_sync_entity: 0.1
valve_open_percent: 18
power_percent: 20
on_percent: 0.2
vtherm_over_climate_valve:
  have_valve_regulation: true
  valve_regulation:
    underlyings_valve_regulation:
      - - number.salon_radiateur_cour_valve_opening_degree
        - number.salon_radiateur_cour_valve_closing_degree
      - - number.salon_radiateur_baie_vitree_valve_opening_degree
        - number.salon_radiateur_baie_vitree_valve_closing_degree
      - - number.salon_radiateur_fenetre_sente_valve_opening_degree
        - number.salon_radiateur_fenetre_sente_valve_closing_degree
    on_percent: 0.2
    power_percent: 20
    function: tpi
    tpi_coef_int: 0.07520694540809986
    tpi_coef_ext: 0.006098097985924204
    tpi_threshold_low: 0
    tpi_threshold_high: 0
    minimal_activation_delay: 10
    minimal_deactivation_delay: 0
    min_opening_degrees: ""
    opening_threshold_degree: 5
    max_closing_degree: 100
    max_opening_degrees: ""
    valve_open_percent: 18
    auto_regulation_dpercent: 5
    auto_regulation_period_min: 5
    last_calculation_timestamp: "2026-01-29T13:29:42.627833+01:00"
  underlying_valves:
    number.salon_radiateur_cour_valve_opening_degree:
      hvac_action: heating
      percent_open: 18
      last_sent_opening_value: 14
      min_opening_degree: 0
      max_opening_degree: 100
    number.salon_radiateur_baie_vitree_valve_opening_degree:
      hvac_action: heating
      percent_open: 18
      last_sent_opening_value: 14
      min_opening_degree: 0
      max_opening_degree: 100
    number.salon_radiateur_fenetre_sente_valve_opening_degree:
      hvac_action: heating
      percent_open: 18
      last_sent_opening_value: 14
      min_opening_degree: 0
      max_opening_degree: 100
friendly_name: Salon - Vthermostat
supported_features: 401

#version

Versatile version 8.6.2
Versatile Thermostat Auto-TPI Learning Card 1.0.9

You will find below AutoTPI graph

As you may see, my graph started after VTherm last update, I did a TPI reset before starting back auto TPI. TPint was at 0.5 initialy and TPext at 0.05.

I don't understand why TPI fall very agressive on boot and after is very very slow to increase back, creating a situation of having hours of being below temperature setpoint because opening is very very small.

Do i miss something regarding config ? I'm very open to test any change on my config :)

Précision: overheat period here is because of a wood stove within the living room.

EDIT: Jan 29th at 16:00, notif received:

Auto TPI has reached the maximum consecutive Kint boost limit (5). The temperature is not rising despite increased power demand. This may indicate undersized heating or abnormal heat loss. Learning will continue normally, but Kint boosting is paused until external temperature rises.

Etienne

[jmcollin78]

Hello, I let @KipK (our Auto-TPI developer) answer your legit question.

[KipK]

Hi,

Here is why it behaves like this with valves: #1704
It's not only auto tpi that behaves bad, but TPI itself, because of non linear power curve.
The effective power range is only at the beginning of the curve. Above 20-30% there's no much difference. Auto TPI then think the heater is too powerfull as just giving 20% power percent, effectively output like 100%
That's why it decrease Kint this much.
Try to adjust your min max opening to the effective range ( like in the post between 5-20% ) as everything above is useless for now. It should improve a bit, but still won't be perfect until we have a way to do a 3 points calibration of the heating curve on the thermostat itself.

[eflye-veepeetech]

I see that the stars are aligned in the analysis of Vtherm's behavior :D I will have a look closely to the post and your reco. Thanks !

[jmcollin78]

Hi,

Here is why it behaves like this with valves: #1704 It's not only auto tpi that behaves bad, but TPI itself, because of non linear power curve. The effective power range is only at the beginning of the curve. Above 20-30% there's no much difference. Auto TPI then think the heater is too powerfull as just giving 20% power percent, effectively output like 100% That's why it decrease Kint this much. Try to adjust your min max opening to the effective range ( like in the post between 5-20% ) as everything above is useless for now. It should improve a bit, but still won't be perfect until we have a way to do a 3 points calibration of the heating curve on the thermostat itself.

then maybe @eflye-veepeetech should avoid auto-TPI and set the coefs manually. What do you think ?

[KipK]

@jmcollin78 II think if the min/max opening valve is set correctly, it should work "ok" , at least should find "working" coeff, but still, the TPI algo has flaws on such situation as the curve is still not linear.
I can't test here unfortunately.

@caiusseverus made a tremendous work, it explains a lot of issues.
edit: you should also give a look on his post how he handle calibration loss, it's pretty clever.

For now I would advice to use the internal TVRZB regulation instead of TPI as it was enginered with the current hardware in mind.

[eflye-veepeetech]

Very clear, i'll do my homework and read closely @caiusseverus post.

maybe a clarification within the documentation could be helpful from both of you regarding TPI / AutoTPI regarding valves integration on Vhterm?

[KipK]

However @eflye-veepeetech I'd like you to test auto-tpi after you have well configured the min/max opening and post the graph here to compare.

[KipK]

other thing , if your boiler adjust water temperature with external T° sensor, then it's useless.
As Kint is pretty dependant to water temperature going in the heater ( it changes the heat rate ) . Nor autoTPI nor TPI can handle this properly for now.

[eflye-veepeetech]

other thing , if your boiler adjust water temperature with external T° sensor, then it's pretty useless. As Kint is pretty dependant to water temperature going in the heater ( it changes the heat rate ) . Nor autoTPI nor TPI can handle this properly for now.

For now no, i don't have any boiler adjust water temperature with external T° sensor. It could change in the future (i have a Frisquet boiler, there's active project around it especialy on hacf forum, with LoRA module and use external sensor on it)

[eflye-veepeetech]

However @eflye-veepeetech I'd like you to test auto-tpi after you have well configured the min/max opening and post the graph here to compare.

What do you think about
max_opening_degrees -> 30
minimum_opening_degrees -> 10
opening_threshold -> 5

@KipK ?

[KipK]

I don't know it depends of your setup. Follows caius advice on how to set them:

The opening threshold degree is the point at which the thermostat is deemed active. I'd suggest starting with it at 0 for initial testing, but you can set it to whatever you want your activation threshold to be so the thermostat turns off at very low output levels.

Minimum valve position - this should be the point at which water starts to flow into your radiator. It's best to find this experimentally rather than guess as the ramp up is so fast. Turn the TRV down and wait until the radiator is cold. Then fire up the heating so the water circulating is hot. Manually tweak the valve closed position down from 100, 1 percent at a time, to cause the valve to open. Pause for a while between each one and feel the radiator pipes to see if they have started to warm up. Check both because sometimes the TRV is on the outlet of the radiator not the inlet. If you have access to a thermal camera it makes this step really easy as you can see straight away when there is the slightest warmth entering the radiator.

For the max valve position, I guess you have to check when the heating curve get's linear. Means there's no power increase anymore.
Increase step by step, wait the time needed to see the temperature change Increase again, wait the same time as before, etc. Then check the history graph of current temperature, you should see the exponential t° curve starting to get linear at some point. This should be the max.

Or use an infrared thermometer or thermal cam to mesure heater t°. When t° doesn't increase anymore significantly means you've reached the max.

You can also try caius blueprint he posted, but follow his intructions. Seems a better way.

[eflye-veepeetech]

Hello, i tried in a smaller room (one radiator) but still the same behaviour at the end with my first attempt

min_opening_degree: 10
max_opening_degree: 30
opening_threshold_degree: 5

Full conf below

icon: mdi:brain
friendly_name: Chambre parents - Vthermostat Auto TPI Learning State
coeff_int_cycles: 42
coeff_ext_cycles: 308
heating_cycles_count: 822
thermal_time_constant_hours: 56.77
model_confidence: 0.92
last_learning_status: gap_too_large_for_outdoor(gap=2.22 > 1.0)
learning_start_dt: "2026-01-30T21:08:17.264593+01:00"
allow_kint_boost_on_stagnation: true
allow_kext_compensation_on_overshoot: true
bootstrap_failure_count: 0
max_capacity_heat: 0.15762066529888447
capacity_heat_status: learned
capacity_heat_value: 0.15762066529888447
capacity_heat_count: 3
calculated_coef_int: 0.017615206963158794
calculated_coef_ext: 0.00547649990155983

hvac_modes:
  - heat
  - sleep
  - "off"
min_temp: 7
max_temp: 35
target_temp_step: 0.1
current_temperature: 16.8
temperature: 19
hvac_action: heating
hvac_mode: heat
preset_mode: none
ema_temp: 16.8
specific_states:
  is_on: true
  last_central_mode: Auto
  last_update_datetime: "2026-02-02T17:47:55.164210+01:00"
  ext_current_temperature: 7.5
  last_temperature_datetime: "2026-02-02T17:44:52.167427+01:00"
  last_ext_temperature_datetime: "2026-02-02T17:47:55.155403+01:00"
  is_device_active: true
  device_actives:
    - number.chambre_parents_radiateur_valve_opening_degree
  nb_device_actives: 1
  ema_temp: 16.8
  temperature_slope: -0.26
  hvac_off_reason: null
  total_energy: 67627
  last_change_time_from_vtherm: "2026-02-02T17:46:19.987575+01:00"
  messages: []
  is_sleeping: false
  is_locked: false
  is_recalculate_scheduled: false
  auto_tpi_state: "on"
  auto_tpi_learning:
    coeff_indoor_heat: 0.017615206963158794
    coeff_outdoor_heat: 0.00547649990155983
    coeff_indoor_autolearn: 43
    coeff_outdoor_autolearn: 308
    max_capacity_heat: 0.15762066529888447
    offset: 0
    last_power: 0.1
    last_order: 19.000000000000025
    last_temp_in: 16.78
    last_temp_out: 7.3
    last_state: heat
    previous_state: heat
    last_on_temp_in: 16.78
    last_update_date: "2026-02-02T17:46:35.430549+01:00"
    last_heater_stop_time: "2026-02-02T17:46:35.427451+01:00"
    cycle_start_date: "2026-02-02T17:46:35.430549+01:00"
    cycle_active: true
    current_cycle_cold_factor: 0.000002581666666666667
    current_cycle_params:
      on_time_sec: 30
      off_time_sec: 269
      on_percent: 0.1
      hvac_mode: heat
    consecutive_failures: 0
    autolearn_enabled: true
    last_learning_status: gap_too_large_for_outdoor(gap=2.22 > 1.0)
    total_cycles: 822
    consecutive_boosts: 0
    regime_change_detected: true
    learning_start_date: "2026-01-30T21:08:17.264593+01:00"
    capacity_heat_learn_count: 3
    bootstrap_failure_count: 0
    allow_kint_boost: true
    allow_kext_overshoot: true
configuration:
  ac_mode: false
  type: over_climate_valve
  is_controlled_by_central_mode: true
  target_temperature_step: 0.1
  timezone: Europe/Paris
  temperature_unit: °C
  is_used_by_central_boiler: true
  max_on_percent: null
  have_valve_regulation: true
  cycle_min: 5
  minimal_activation_delay_sec: 10
  minimal_deactivation_delay_sec: 0
preset_temperatures:
  frost_temp: 7
  eco_temp: 17
  boost_temp: 21
  comfort_temp: 19
  frost_away_temp: 0
  eco_away_temp: 0
  boost_away_temp: 0
  comfort_away_temp: 0
current_state:
  hvac_mode: heat
  target_temperature: 19.000000000000025
  preset: none
requested_state:
  hvac_mode: heat
  target_temperature: 19.000000000000025
  preset: none
is_presence_configured: false
is_power_configured: false
power_manager:
  device_power: 2208
  mean_cycle_power: 220.8
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_turn_off
  is_window_bypass: false
  window_sensor_entity_id: binary_sensor.chambre_parents_fenetre_contact
  window_delay_sec: 30
  window_off_delay_sec: 30
  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
  safety_default_on_percent: 0
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: true
heating_failure_detection_manager:
  heating_failure_state: "off"
  cooling_failure_state: "off"
  heating_failure_threshold: 0.9
  cooling_failure_threshold: 0
  detection_delay_min: 15
  temperature_change_tolerance: 0.5
  failure_detection_enable_template: null
  is_detection_enabled_by_template: true
  heating_tracking:
    is_tracking: false
    initial_temperature: null
    current_temperature: null
    remaining_time_min: null
    elapsed_time_min: null
  cooling_tracking:
    is_tracking: false
    initial_temperature: null
    current_temperature: null
    remaining_time_min: null
    elapsed_time_min: null
is_auto_start_stop_configured: false
fan_mode: null
fan_modes: []
is_over_climate: true
regulation_accumulated_error: 0
regulated_target_temperature: null
vtherm_over_climate:
  start_hvac_action_date: "2026-02-02T17:46:19.988846+01:00"
  last_mean_power_cycle: 220.8
  underlying_entities:
    - climate.chambre_parents_radiateur
  is_regulated: true
  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
  regulation:
    regulated_target_temperature: null
    auto_regulation_mode: auto_regulation_valve
    regulation_accumulated_error: 0
  temp_synchronisation:
    sync_entity_ids:
      - number.chambre_parents_radiateur_external_temperature_input
    sync_with_calibration: false
    sync_attributes:
      number.chambre_parents_radiateur_external_temperature_input:
        value: 16.8
        min_sync_entity: 0
        max_sync_entity: 99.9
        step_sync_entity: 0.1
valve_open_percent: 7
power_percent: 10
on_percent: 0.1
vtherm_over_climate_valve:
  have_valve_regulation: true
  valve_regulation:
    underlyings_valve_regulation:
      - - number.chambre_parents_radiateur_valve_opening_degree
        - number.chambre_parents_radiateur_valve_closing_degree
    on_percent: 0.1
    power_percent: 10
    function: tpi
    tpi_coef_int: 0.017615206963158794
    tpi_coef_ext: 0.00547649990155983
    tpi_threshold_low: 0
    tpi_threshold_high: 0
    minimal_activation_delay: 10
    minimal_deactivation_delay: 0
    min_opening_degrees: "10"
    opening_threshold_degree: 5
    max_closing_degree: 100
    max_opening_degrees: "30"
    valve_open_percent: 7
    auto_regulation_dpercent: 5
    auto_regulation_period_min: 5
    last_calculation_timestamp: "2026-02-02T12:49:45.341603+01:00"
  underlying_valves:
    number.chambre_parents_radiateur_valve_opening_degree:
      hvac_action: heating
      percent_open: 7
      last_sent_opening_value: 10
      min_opening_degree: 10
      max_opening_degree: 30
friendly_name: Chambre parents - Vthermostat
supported_features: 401
preset_modes:
  - none
  - frost
  - eco
  - comfort
  - boost

[KipK]

And are you sure the min max value you've puit are ok ? They need to be exactly the effective range. It looks like you've just choosen randomly 10-30 ain't it ?

Also read the auto TPI doc as it seems you haven't follow at all the guidelines for a correct auto tpi learning session. I see no setpoint changes to gives Kint learning window. It's just always the same setpoint for days.

Looking at the regulation anyway it seems the value it choosed are still ok as the temp curve seems to stick to the set point quiet good, so for me your power range is still not adjusted to your valve, but it still work with those low Kint

[eflye-veepeetech]

ok i'll try to do a more accurate test than this one :)