Kaisai Heat Pump KHA, KMK, KMC
Monitors and controls Kaisai air heat pump systems via Modbus RTU.
This template connects Kaisai KHA, KMK, KMC, and KHC air heat pumps to ModbusCloud via Modbus RTU at 9600 baud. It reads temperatures, operating mode, fault codes, power output, and electricity consumption. It also allows remote control of the operating mode and power on/off.
- Protocol
- Modbus RTU
- Connection
- RS485, 9600 baud
- Registers
- 11, read and write
- Brand
- Kaisai
- Key readings
- Operating Mode · T4 Temperature · Ta Room Temperature · T5 Water Tank Temperature · Current Fault · Power Output and Electricity Consumption
- Available commands
- Setting the Mode · Power On Off
- Compatible models
- KHA · KMK · KMC · KHC
- Last updated
Registers (11)
9 read, 2 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Operating Mode | Read | ||||
| T4 Temperature | °C | Read | |||
| Ta Room Temperature | °C | Read | |||
| T5 Water Tank Temperature | °C | Read | |||
| Current fault | Read | ||||
| Compressor operation time | hour | Read | |||
| Load output | Read | ||||
| Power output | kW | Read | |||
| Electricity consumption | kWh | Read | |||
| Setting the mode | Write | ||||
| Power On Off | Write |
Loading registers…
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Monitor water tank temperature and room temperature remotely to verify heating performance for your customer.
- Create an alert when a fault code appears so you can respond before the end user notices a problem.
- Track electricity consumption and power output over time to calculate the heat pump coefficient of performance.
- Switch the heat pump on or off remotely to support demand-side energy management or seasonal shutdown.
- Log compressor runtime to plan preventive maintenance intervals and reduce unexpected downtime.
- Compare operating data across multiple Kaisai installations in a single ModbusCloud dashboard.
Installation
Connect the ModbusCloud Gateway to the Kaisai heat pump RS-485 terminals using a twisted pair cable with correct A/B polarity.
Set the Modbus slave address on the Kaisai heat pump via its built-in controller menu, and note the address for configuration in ModbusCloud.
Confirm the baud rate is set to 9600, 8 data bits, 1 stop bit, no parity on both the heat pump and the gateway.
Import the Kaisai KHA/KMK/KMC template from the ModbusCloud template library and assign it to the gateway.
Verify that live readings such as T4 temperature and operating mode appear on the ModbusCloud dashboard before closing the installation.
Things to watch for
Power output and electricity consumption show incorrect or zero values. What is wrong?
These registers (40146 and 40144) are uint32 values spanning two consecutive addresses. Make sure the template is correctly configured to read 32-bit values. If you have modified the template, verify that the register count is set to 2 for each of these data points.
The gateway cannot communicate with the heat pump. What should I check?
Verify RS-485 wiring polarity (A to A, B to B). Confirm the baud rate is 9600 on both devices. Ensure the correct Modbus slave address is entered in the ModbusCloud gateway configuration.
Is the KHC model supported by this template?
Yes. The KHC variant shares the same Modbus register map as the KHA, KMK, and KMC models and is fully supported by this template.
Can I control the heat pump operating mode remotely without affecting local thermostat settings?
The template writes the operating mode register on the heat pump. Depending on the Kaisai controller configuration, a local thermostat override may take priority. Consult the Kaisai installation manual for details on Modbus vs. local control priority.
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