Why does the outdoor temperature show an incorrect or very high value?

Register 118 for outdoor temperature uses a signed int16 data type. If your setup interprets it as unsigned uint16, negative temperatures will appear as large positive numbers. The template handles this automatically, but verify that no custom override changes the data type.

What baud rate should I set on the heat pump?

The default baud rate for this template is 9600. Make sure the Sinclair heat pump and the Modbus gateway are both set to 9600 baud, 8N1. A mismatch will prevent communication.

Can I control the heat pump and read data at the same time?

Yes. The template defines both read and write registers. Reading status and temperatures happens on a polling cycle, while control commands such as on/off or setpoint changes are sent when you trigger them from the dashboard.

How do I know which model variant I have?

Check the model label on the outdoor unit. The template supports all SMH-IRB, SMH-IRBC, SMH5-B, and SMH5-BC variants from 40 to 160 size classes, including three-phase models ending in -3.

Free Modbus template: S-therm Ontario

Name: S-therm Ontario
Brand: Sinclair
SKU: 1b6f6345-28ce-421b-b927-46cf981b592e

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Free Modbus template: S-therm Ontario | ModbusCloud

Registers (30)

30 read / 21 write

Name	Address	Function	Type	Unit	Access
Mode	2	FC03	uint16		R/W
Optional E-Heater	3	FC03	uint16		R/W
WOT-Cool	9	FC03	uint16	℃	R/W
WOT-Heat	10	FC03	uint16	℃	R/W
RT-Cool	11	FC03	uint16	℃	R/W
RT-Heat	12	FC03	uint16	℃	R/W
T-water tank	13	FC03	uint16	℃	R/W
T-Eheater	14	FC03	uint16	℃	R/W
T-Other switch on	15	FC03	uint16	℃	R/W
Upper AT-Heat	17	FC03	uint16	℃	R/W
Lower AT-Heat	18	FC03	uint16	℃	R/W
Upper RT-Heat	19	FC03	uint16	℃	R/W
Lower RT-Heat	20	FC03	uint16	℃	R/W
Upper WT-Heat	21	FC03	uint16	℃	R/W
Lower WT-Heat	22	FC03	uint16	℃	R/W
△T-Cool	29	FC03	uint16	℃	R/W
△T-Heat	30	FC03	uint16	℃	R/W
△T-hot water	31	FC03	uint16	℃	R/W
△T-Room temp	32	FC03	uint16	℃	R/W
On_Off	42	FC03	uint16		R/W
Error reset	44	FC03	uint16		R/W
Unit status	117	FC03	uint16		R
T-outdoor	118	FC03	int16	℃	R
T-water out PE	125	FC03	uint16	℃	R
T-optional water sen.	126	FC03	uint16	℃	R
T-water in PE	127	FC03	uint16	℃	R
T-tank ctrl.	128	FC03	uint16	℃	R
T-remote room	129	FC03	uint16	℃	R
Thermostat	132	FC03	uint16		R
T-weather depend	137	FC03	uint16	℃	R