#substitutions is a list of variables basically. here you can easily change the high/low limits and setpoints
substitutions:
  temperature_setpoint: '25.5'
  temperature_alarm_low: '23.3'
  temperature_alarm_high: '27.5'
  temperature_hysteresis: '0.3'
esphome:
  name: thermostat
  platform: ESP8266
  board: nodemcuv2
  esp8266_restore_from_flash: True
  on_boot:
    priority: -10
    # ...
    then:
      #on boot we turn the thermostat on ("HEAT" mode in my case) and set the desired setpoint
      - climate.control:
          id: temp_control
          mode: HEAT
          target_temperature: ${temperature_setpoint}
      #This script begins the monitor that makes sure we receive a new temperature measurement at least every 2 minutes
      #If this script isn't called every 2 minutes it will start the high temperature alarm
      #Everytime we call the script the timer resets. I call this the temperature "heartbeat"
      - script.execute: temperature_heartbeat

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  ap:
    ssid: thermostat
    password: !secret ap_password

web_server:
  port: 80

logger:

api:

ota:

captive_portal:

sensor:
  - platform: dht
    pin: D5
    temperature:
      name: "Test Room Temperature"
      id: temp_1
    humidity:
      name: "Test Room Humidity"
    update_interval: 60s
switch:
  - platform: gpio
    pin: D8
    id: Relay
    name: "Heating Element Relay"
climate:
  - platform: thermostat
    name: "thermostat_test"
    id: temp_control
    #Note that here the same temperature sensor that has all of the alarms configured is used to control the thermostat
    sensor: temp_1
    default_target_temperature_low: ${temperature_setpoint}
    hysteresis: ${temperature_hysteresis}
    heat_action:
      - switch.turn_on: Relay
    idle_action:
      - switch.turn_off: Relay
script:
  - id: temperature_heartbeat
    mode: restart
    then:
      - delay: 2 min