ESP Heater Relay

Control your Heater with an ESP relay via Home Assistant.

The temperature is read from another Home Assistant sensor, if the remote sensor / HA is not available the internal sensor is used.

Step 1: Needed Components

1. 220V to 5vdc transformer
2. Wemos D1 mini ( / pro for better wireless range)
3. DHT22
4. 1 Channel relay
5. Relay box

Step 2: Coonecting the Pieces

From the power source 5v output 3 wires will go to:

• wemos d1 mini (5v and ground)
• the relay (5v and ground)
• dht22 (5v to pin1, gnd to pin 4)

Data pins

1. relay (d1 mini pin D1 to the IN pin)
2. dht22 (d1 mini pin D2 to pin 2)

Step 3: The ESPHome Code

esphome:
  name: thermicstation-relay
  on_boot: 
    priority: 500
    then:
      - climate.control:
          id: ${location}_thermostat
          mode: "HEAT"

esp8266:
  board: d1_mini

# Enable logging
logger:


substitutions:
  default_temp_low: "15.0"
  room: Kitchen
  location: "moon"
  remote_sensor: "sensor.bme680_temperature"

climate:
  - platform: thermostat
    min_heating_off_time: 60s
    min_heating_run_time: 60s
    min_idle_time: 0s
    visual:
      min_temperature: 15 °C
    name: "${location} ${room} Thermostat"
    id: ${location}_thermostat
    sensor: active_temp

    default_mode: heat
    default_target_temperature_low: ${default_temp_low}
    heat_deadband: 0.3
    heat_overrun: 0.3

    heat_action:
      - switch.turn_on: ${location}_thermicstation_relay

    idle_action:
       - switch.turn_off: ${location}_thermicstation_relay

switch:
  - platform: gpio
    name: "${location}-thermicstation-relay"
    id: "${location}_thermicstation_relay"
    pin:
      number: D1

sensor:
  - platform: dht
    id: "${location}_internal_dht22"
    pin: D2
    model: DHT22
    temperature:
      name: "${location} Thermicstation Temperature"
      id: "${location}_internal_dht22_temp"
    humidity:
      name: "${location} Thermicstation Humidity"
      id: "internal_dht22_humidity"
    update_interval: 60s

  - platform: homeassistant
    name: "Input Temp From Home Assistant"
    id: remote_temp
    entity_id: ${remote_sensor}

  - platform: template
    name: "Active Thermicstation Input Temp"
    id: active_temp
    lambda: |-
      if (isnan(id(remote_temp).state)){
        return id(${location}_internal_dht22_temp).state;
      } else {
        return id(remote_temp).state;
      }
    update_interval: 60s

# Enable Home Assistant API
api:

ota:
  password: "<secret>"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  fast_connect: true

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Thermicstation-Relay"
    password: "<secret>"

captive_portal: