HeishaMon Save

Panasonic Aquarea air-water H and J series protocol decrypt

Project README

Join us on Slack chat room

Panasonic H & J Series Aquarea air-water heat pump protocol

This project makes it possible to read information from Panasonic Aquarea heat pump and report the data either to an MQTT server or as JSON format over HTTP.

Eine deutschsprachige README_DE.md findest du hier.
Een nederlandse vertaling README_NL.md vind je hier.
Suomen kielellä README_FI.md luettavissa täällä.

Help on translation to other languages is welcome.

Current releases

Current release is version 2. The compiled binary can be installed on a Wemos D1 mini, on the HeishaMon PCB and generally on any ESP8266 based board compatible with Wemos build settings (at least 4MB flash). You can also download the code and compile it yourself (see required libraries below).

Using the software

HeishaMon is able to communicate with the Panasonic Aquarea H & J-series. Confirmed by users types of HP you can find here
If you want to compile this image yourself be sure to use the mentioned libraries and support for a filesystem on the esp8266 so select the correct flash option in arduino ide for that.

When starting, without a configured wifi, an open-wifi-hotspot will be visible allowing you to configure your wifi network and your MQTT server. Configuration page will be located at . \

After configuring and booting the image will be able to read and talk to your heatpump. The GPIO13/GPIO15 connection will be used for communications so you can keep your computer/uploader connected to the board if you want.
Serial 1 (GPIO2) can be used to connect another serial line (GND and TX from the board only) to read some debugging data.

All received data will be sent to different MQTT topics (see below for topic descriptions). There is also a 'panasonic_heat_pump/log' MQTT topic which provides debug logging and a hexdump of the received packets (if enabled in the web portal).

You can connect a 1wire network on GPIO4 which will report in seperate MQTT topics (panasonic_heat_pump/1wire/sensorid).

The software is also able to measure Watt on a S0 port of two kWh meters. You only need to connect GPIO12 and GND to the S0 of one kWh meter and if you need a second kWh meter use GPIO14 and GND. It will report on MQTT topic panasonic_heat_pump/s0/Watt/1 and panasonic_heat_pump/s0/Watt/2 and also in the JSON output. You can replace 'Watt' in the previous topic with 'Watthour' to get consumption counter in WattHour (per mqtt message) or to 'WatthourTotal' to get the total consumption measured in WattHour.

Updating the firmware is as easy as going to the firmware menu and, after authentication with username 'admin' and password 'heisha' (or other provided during setup), uploading the binary there.

A json output of all received data (heatpump and 1wire) is available at the url http://heishamon.local/json (replace heishamon.local with the ip address of your heishamon device if MDNS is not working for you).

Within the 'integrations' folder you can find examples how to connect your automation platform to the HeishaMon.

Rules functionality

The rules functionality allows you to control the heatpump from within the HeishaMon itself. Which makes it much more reliable then having to deal with external domotica over WiFi. When posting a new ruleset, it is immidiatly validated and when valid used. When a new ruleset is invalid it will be ignored and the old ruleset will be loaded again. You can check the console for feedback on this. If somehow a new valid ruleset crashes the HeishaMon, it will be automatically disabled the next reboot allowing you to make changes. This prevents the HeishaMon getting into a boot loop.

The techniques used in the rule library allows you to work with very large rulesets, but best practice is to keep it below 10.000 bytes.

Notice that sending commands to the heatpump is done asynced. So, commands sent to the heatpump at the beginning of your syntax will not immediatly be reflected in the values from the heatpump later on. Therefor, heatpump values should therefor be read from the heatpump itself instead of those based on the values you keep yourself.


Two general rules are that spaces are mandatory and all lines are terminated by a semicolon.


The ruleset uses the following variable structure:

  • #: Globals These variables can be accessed throughout the ruleset. Don't use globals for all your variables, because it will persistantly use memory.

  • $: Locals These variables live inside a rule block. When a ruleblock finishes, these variables will be cleaned up, freeing any memory used.

  • @: Heatpump parameters These are the same as listed in the Manage Topics documentation page and as found on the HeishaMon homepage. So the heatpump state value is named @Heatpump_State.

  • ?: Thermostat parameters These variables reflect parameters read from the connected thermostat when using the OpenTherm functionality. When OpenTherm is supported this documentation will be extended with more precise information.

  • ds18b20#2800000000000000: Dallas 1-wire temperature values Use these variables to read the temperature of the connected sensors. These values cannot be used as an event and are as an exception readonly. Off course, the id of the sensor should be places after the hashtag.

All variables are either read of write enabled. Writing to either the Heatpump of Thermostat parameters directly control these devices. So @Heatpump_State = 1 will actually turn the heatpump off.

When a variable is called but not yet set to a value, the value will be NULL.

Variables can be of boolean (1 or 0), float (3.14), or integer (10) type.

Events or functions

Rules are written in event or function blocks. These are blocks that are triggered when something happened; either a new heatpump or thermostat value has been received or a timer fired. Or can be used are plain functions

on [event] then

on [name] then

Events can be Heatpump or thermostat parameters or timers:

on @Heatpump_State then

on ?setpoint then

on timer=1 then

When defining function, you just name your block and then you can call it from anywhere else:

on foobar then

on @Heatpump_State then

There is currently one special function that calls when the system is booted on when a new ruleset is saved:

on System#Boot then

This special function can be used to initially set your globals or certain timers.


Regular operators are supported with their standard associativity and precedence. This allows you to also use regular math.

  • &&: And
  • ||: Or
  • ==: Equals`
  • >=: Greater or equal then
  • >: Greater then
  • <: Lesser then
  • <=: Lesser or equal then
  • -: Minus
  • %: Modulus
  • *: Multiply
  • /: Divide
  • +: Plus
  • ^: Power

Parenthesis can be used to prioritize operators as it would work in regular math.


  • coalesce Returns the first value not NULL. E.g., $b = NULL; $a = coalesce($b, 1); will return 1. This function accepts an unlimited number of arguments.

  • max Returns the maximum value of the input parameters.

  • min Returns the minimum value of the input parameters.

  • isset Return boolean true when the input variable is still NULL in any other cases it will return false.

  • round Rounds the input float to the nearest integer.

  • setTimer Sets a timer to trigger in X seconds. The first parameter is the timer number and the second parameters the number of seconds before it fires. A timer only fires once so it has to be re-set for recurring events. When a timer triggers it will can the timer event as described above.


The only supported conditions are if and else, elseif isn't supported:

if [condition] then
  if [condition] then


Once the rules system is in used by more and more users, additional examples will be added to the documentation.

Calculating WAR

on calcWar then
	$Ta1 = 32;
	$Tb1 = 14;
	$Ta2 = 41;
	$Tb2 = -4;

	#maxTa = $Ta1;

	if @Outside_Temp >= $Tb1 then
		#maxTa = $Ta1;
		if @Outside_Temp <= $Tb2 then
			#maxTa = $Ta2;
			#maxTa = $Ta1 + (($Tb1 - @Outside_Temp) * ($Ta2 - $Ta1) / ($Tb1 - $Tb2));

Thermostat setpoint

on ?temperature then

	$margin = 0.25;

	if ?temperature > (?setpoint + $margin) then
		if @Heatpump_State == 1 then
			@Heatpump_State = 0;
		if ?temperature < (?setpoint - $margin) then
			if @Heatpump_State == 0 then
				@Heatpump_State = 1;
			@SetZ1HeatRequestTemperature = round(#maxTa);

Factory reset

A factory reset can be performed on the web interface but if the web interface is unavailable you can perform a double reset. The double reset should be performed not too fast but also not too slow. Usually halve a second between both resets should do the trick. To indicate that the double reset performed a factory reset, the blue led will flash rapidly (You need to press reset again now to restart HeishaMon back to normal where a WiFi hotspot should be visible again).

Further information

Below you can find some technical details about the project. How to build your own cables. How to build your own PCB etc.

Connection details:

Communication can be established thru one of the two sockets: CN-CNT or CN-NMODE. If you have an existing Panasonic CZ-TAW1 WiFi interface that you want to replace with HeishaMon, it is only a matter of plugging the cable out from CZ-TAW1 and reconnecting to your HeishaMon device. However it is not possible to use HeishaMon and the original CZ-TAW1 module together as an active device. It is however possible to put HeishaMon on "Listen Only" mode which will allow HeishaMon and the original CZ-TAW1 module to co-exist. The only downside to this is that HeishaMon is unable to send commands and use the optional PCB option.

Communication parameters: TTL 5V UART 9600,8,E,1

CN-CNT Pin-out (from top to bottom)
1 - +5V (250mA)
2 - 0-5V TX (from heatpump)
3 - 0-5V RX (to heatpump)
4 - +12V (250mA)
5 - GND

CN-NMODE Pin-out (from left to right)
"Warning! As printed on the PCB, the left pin is pin 4 and right pin is pin 1. Do not count 1 to 4 from left!
4 - +5V (250mA)
3 - 0-5V TX (from heatpump)
2 - 0-5V RX (to heatpump)
1 - GND

HeishaMon will receive power from the Panasonic over the cable (5v power).

Long distance connection

It it possible to connect the HeishaMon over a long distance. Up to 5 meter is working with normal cabling. For longer distances a TTL-to-RS485 configuration as show in the picture below is possible. The however requires HeishaMon to be powered externally using 5v power (for example from an USB cable).

TTL-over-RS485 HeishaMon long distance

Where to get connectors

RS-Online orders

Conrad orders

Use some 24 AWG shielded 4-conductors cable.

The HeishaMon hardware itself

The PCB's needed to connect to the heatpump are designed by project members and are listed below. The most important part of the hardware is a level shifting between 5v from the Panasonic to 3.3v of the HeishaMon and a GPIO13/GPIO15 enable line after boot.
PCD Designs from the project members
Picture Wemos D1 beta
Picture ESP12-F

To make things easy you can order a completed PCB from some project members:
Tindie shop from Igor Ybema (aka TheHogNL) based in the Netherlands

Building the arduino image yourself

esp8266 by esp8266 community version 3.0.2 Arduino

All the libs we use necessary for compiling.

MQTT topics

Current list of documented MQTT topics can be found here

DS18b20 1-wire support

The software also supports ds18b20 1-wire temperature sensors reading. A proper 1-wire configuration (with 4.7kohm pull-up resistor) connected to GPIO4 will be read each configured secs (minimal 5) and send at the panasonic_heat_pump/1wire/"sensor-hex-address" topic. On the pre-made boards this 4.7kohm resistor is already installed.

Protocol byte decrypt info:

Current list of documented bytes decrypted can be found here

Integration Examples for Opensource automation systems


Home Assistant

IOBroker Manual


Open Source Agenda is not affiliated with "HeishaMon" Project. README Source: Egyras/HeishaMon
Open Issues
Last Commit
2 weeks ago

Open Source Agenda Badge

Open Source Agenda Rating