can't get it set up : it always cuts the heater

[jpberry]

Describe the bug
I'm trying to set up smart thermostat

To Reproduce

1. Set up the thermostat and set up the yaml file. Here is mine

climate:

• platform: smart_thermostat
  name: Smart Thermostat
  unique_id: smart_thermostat
  heater: switch.prise3
  target_sensor: sensor.tempZ8_couloir_temperature
  min_temp: 7
  max_temp: 28
  ac_mode: False
  target_temp: 15
  keep_alive:
  seconds: 5
  away_temp: 14
  kp: 50
  ki: 0.01
  kd: 2000
  pwm: 00:00:15

2. set the target temp to 25 : works fine. If I set switch.prise3 on, it will switch off rapidly. That is what I was expecting - too hot, lets stop the heater
3. set the target temp to 15 (as it is in the previous example), and RESTART HA. Doesn't work. If I flip the switch, it will switch back in a few seconds. Every time.

Screenshots

Desktop (please complete the following information):

• OS: ubuntu 24
• BrowserBrave 1.84.132 (Official Build) (64-bit)
  Chromium: 142.0.7444.60

Installation method Home Assistant OS
Core 2025.10.4
Supervisor 2025.10.0
Operating System 16.2
Frontend 20251001.4

What am I doing wrong ???

[ScratMan]

The PWM period is set to 15 seconds. That's much too low for a thermal cycle.

[jpberry]

Yep, I set it low for testing purposes.

I changed it to 15 mn. Same thing : I put a target of 25 °c. My current temp is 20.9. I'm expecting it to heat like hell. It just switches the thing off after a few seconds.

BTW, I got it wrong in my original post : it should switch off with a target of 15, and heat with a target of 25. Not important, the thing behaves the same way, whether the target is 15 or 25 : each time I switch it on manually, the system turns it back off after a few seconds.

[ScratMan]

Please add the debug: true parameter to your yaml, configure some template sensors to monitor the attributes, enable the HA logging for the integration, and restart Home Assistant, as explained in the readme.

• debug (Optional): Make the climate entity expose the following internal values as extra
  states attributes, so they can be accessed in HA with sensor templates for debugging purposes (
  helpful to adjust the PID gains), example configuration.yaml:

  sensor:
  - platform: template
    sensors:
      smart_thermostat_output:
        friendly_name: PID Output
        unit_of_measurement: "%"
        value_template: "{{ state_attr('climate.smart_thermostat_example', 'control_output') | float(0) }}"
        smart_thermostat_p:
        friendly_name: PID P
        unit_of_measurement: "%"
        value_template: "{{ state_attr('climate.smart_thermostat_example', 'pid_p') | float(0) }}"
      smart_thermostat_i:
        friendly_name: PID I
        unit_of_measurement: "%"
        value_template: "{{ state_attr('climate.smart_thermostat_example', 'pid_i') | float(0) }}"
      smart_thermostat_d:
        friendly_name: PID D
        unit_of_measurement: "%"
        value_template: "{{ state_attr('climate.smart_thermostat_example', 'pid_d') | float(0) }}"
      smart_thermostat_e:
        friendly_name: PID E
        unit_of_measurement: "%"
        value_template: "{{ state_attr('climate.smart_thermostat_example', 'pid_e') | float(0) }}"
  

  It is strongly recommended to disable the debug mode once the
  PID Thermostat is working fine, as the added extra states attributes will fill the Home Assistant
  database quickly.
  Available debug attributes are:
  • pid_p
  • pid_i
  • pid_d
  • pid_e
  • pid_dt

Enable HA logging for integration to have some informations in the HA main logs:

logger:
  logs:
    custom_components.smart_thermostat: debug

Then share the curves from sensors and lines about smart thermostat's in HA's system logs.