Mill panel heater (generation 2)

Device Type:

Electrical Standard:

Board:

Difficulty:Chip needs replacement (5/5)

Project URL:https://github.com/owangen/esphome/tree/dev/esphome/components/mill_panelheater_gen2

General Notes

Mill panel heaters are available in various versions. This component is specifically designed for Generation 2 panel heaters (not compatible with portable heater models). Below is a table that helps you determine which generation you have based on the Wi-Fi serial number prefix (originally linked from Mill’s support article):

Generation overview

Wi-Fi serial starts with	Generation	Approx. year
`SKAG*****`	1	2016
`SKAH*****`	2	2017
`SKAI*****`	2	2018
`SKAJ*****`	2	2019
`SKAK*****`	2	2020
`SKAL*****`	3 / 3M	2021
`SKAN*****`	3 / 3M	2022
`SKAO*****`	3 / 3M	2023
`MI***...`	3 / 3M	2024

If you have a Generation 3 panel heater (which comes with a built-in ESP32), check out this component: https://github.com/ssieb/esphome_components/tree/mill/components/mill_heater To use this component with a Generation 2 panel heater, you’ll need to replace the HF-LPT120A module with an ESP8266. Desolder

HF-LPT120A desoldered

Removed

Solder the ESP8266 in place. Refer to the GPIO Pinout section for detailed instructions

Solder

GPIO Pinout

PIN (mill board)	ESP8266	Description
+3.3V	VCC	Power input (3.3V)
GND	GND	Ground
WTX	TX (GPIO1)	UART transmitter
WRX	RX (GPIO3)	UART receiver

Configuration

substitutions:
  devicename: "millzero_heater"  #Lower case name
  friendly_name: "Mill Zero heater"

esphome:
  name: "${devicename}"

external_components:
  source:
    type: git
    url: https://github.com/owangen/esphome
  components: [ mill_panelheater_gen2 ]

esp8266:
  board: d1_mini

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

captive_portal:

# Enable logging
logger:
  baud_rate: 0 # Deactived to prevent conflict with UART, sending UART to mill controller does not work if enabled

# Enable Home Assistant API
api:

ota:

uart:
  id: uart_bus
  tx_pin: GPIO01
  rx_pin: GPIO03
  baud_rate: 9600

climate:
  - platform: mill_panelheater_gen2
    name: Mill heater

Credits

This component builds on the work by: