Hi all,
I am in the process of installing a Project Curv ASHP hot water cylinder and reached out to the manufacturer for the Modbus registers as they are not in the manual / readily available online.
The aim is to use Modbus instead of the Wi-Fi app to manage/control the cylinder via a Waveshare RS485 device through HA.
Hope this is something of use for anyone else in the future!
| Description | Value |
|---|---|
| Address | 1~254 |
| Mode | RTU |
| Baudrate | 9600bps |
| Start bit | 1 |
| Data bits | 8 |
| Parity | None |
| Stop bits | 1 |
MODBUS interface description domestic-hot-water-heat-pump
| Designation | Read/Write | Supported function codes | Unit | Holding Registers address | Number of registers | Minimum value | Maximum value | Data format |
|---|---|---|---|---|---|---|---|---|
| Slave Address | Read | 0x03 | N/A | 0 | 1 | 1 | 254 | N/A |
| Current mode (which mode is the BW-WP currently in → Auto, Eco, Vac, Elec) | Read/Write | 0x03/0x10 | N/A | 1 | 1 | 0 | 3 | 0 AUTO 1 ECO 2 ELEC 3 VAC（0x03） |
| Current mode (which mode is the BW-WP currently in → Active, Boost, Mute, Sterilize) | Read/Write | 0x03/0x10 | N/A | 2 | 1 | 0000h | FFFFh | bit0 0 deactive 1 active bit1 0 boost off 1 boost on bit2 0 mute off 1 mute on（0x03） bit3 0 sterilize off 1 sterilize on |
| Current operating status (which heat source is currently being used → heat pump, electric heater, heating register thermal solar/boiler) | Read | 0x03 | N/A | 3 | 1 | 0000h | FFFFh | bit0 0 heat pump off 1 heat pump on bit1 0 electric heater off 1 electric heater on bit2 0 solar off 1 solar on bit3 0 boiler off 1 boiler on |
| Current hot water quantity (how full is the tank → in percent) | Read | 0x03 | % | 4 | 1 | 0 | 100 | N/A |
| Target Temperature | Read | 0x03 | °C | 5 | 1 | 1 | 100 | N/A |
| User Set temperature (enter the temperature to which the temperature should be heated → ) | Read/Write | 0x03/0x10 | °C | 6 | 1 | 35 | 75 | N/A |
| Current temperature of the water | Read | 0x03 | °C | 7 | 1 | 0 | 100 | N/A |
| Current temperature of the water tank above | Read | 0x03 | °C | 8 | 1 | 0 | 100 | N/A |
| Current temperature of the water tank below | Read | 0x03 | °C | 9 | 1 | 0 | 100 | N/A |
| Current ambient temperature | Read | 0x03 | °C | 10 | 1 | -50 | 100 | N/A |
| RTC clock | Read | 0x03 | °C | 11 | 7 | N/A | N/A | byte0~1 year YY 0~99 (24 for 2024) byte2~3 month MM 1~12 byte4~5 date DD 1~31 byte6~7 Week 1~7 byte8~9 hour 0~23 byte10~11 minute 0~59 byte12~13 second 0~59 |
| Fault code display | Read | 0x03 | N/A | 18 | 1 | 0 | 64 | 0 None 1~15 E1~EF 16~31 L0~LF 32~47 F0~FF 48~63 P0~PF 64 PP |
| Energy consumption by heat pump (last 7 days, 12 months, 5 years) | Read | 0x03 | kWh | 19~25 26~37 38~42 | 24 | 0000h | FFFFh | byte0~1 Monday byte2~3 Tuesday …… byte12~13 Sunday byte14~15 January byte16~17 February …… byte36~37 December byte38~39 four years ago byte40~41 three years ago byte42~43 the year before last byte44~45 last year byte46~47 this year |
| Energy consumption by heat electric heater (last 7 days, 12 months, 5 years) | Read | 0x03 | kWh | 43~49 50~61 62~66 | 24 | 0000h | FFFFh | byte0~1 Monday byte2~3 Tuesday …… byte12~13 Sunday byte14~15 January byte16~17 February …… byte36~37 December byte38~39 four years ago byte40~41 three years ago byte42~43 the year before last byte44~45 last year byte46~47 this year |
| Accumulated energy consumption (heating power) (last 7 days, 12 months, 5 years) | Read | 0x03 | kWh | 67~73 74~85 86~90 | 24 | 0000h | FFFFh | byte0~1 Monday byte2~3 Tuesday …… byte12~13 Sunday byte14~15 January byte16~17 February …… byte36~37 December byte38~39 four years ago byte40~41 three years ago byte42~43 the year before last byte44~45 last year byte46~47 this year |