diff --git a/homeassistant/components/modbus/__init__.py b/homeassistant/components/modbus/__init__.py
index 043d7375ae3..e8c53469769 100644
--- a/homeassistant/components/modbus/__init__.py
+++ b/homeassistant/components/modbus/__init__.py
@@ -105,6 +105,7 @@ from .const import (  # noqa: F401
     CONF_SWAP_WORD_BYTE,
     CONF_TARGET_TEMP,
     CONF_VERIFY,
+    CONF_WRITE_REGISTERS,
     CONF_WRITE_TYPE,
     CONF_ZERO_SUPPRESS,
     DEFAULT_HUB,
@@ -232,6 +233,7 @@ CLIMATE_SCHEMA = vol.All(
             vol.Optional(CONF_STEP, default=0.5): vol.Coerce(float),
             vol.Optional(CONF_TEMPERATURE_UNIT, default=DEFAULT_TEMP_UNIT): cv.string,
             vol.Optional(CONF_HVAC_ONOFF_REGISTER): cv.positive_int,
+            vol.Optional(CONF_WRITE_REGISTERS, default=False): cv.boolean,
             vol.Optional(CONF_HVAC_MODE_REGISTER): vol.Maybe(
                 {
                     CONF_ADDRESS: cv.positive_int,
@@ -244,6 +246,7 @@ CLIMATE_SCHEMA = vol.All(
                         vol.Optional(CONF_HVAC_MODE_DRY): cv.positive_int,
                         vol.Optional(CONF_HVAC_MODE_FAN_ONLY): cv.positive_int,
                     },
+                    vol.Optional(CONF_WRITE_REGISTERS, default=False): cv.boolean,
                 }
             ),
         }
diff --git a/homeassistant/components/modbus/climate.py b/homeassistant/components/modbus/climate.py
index 5573ef0b7ec..0a8b8dabeeb 100644
--- a/homeassistant/components/modbus/climate.py
+++ b/homeassistant/components/modbus/climate.py
@@ -45,6 +45,7 @@ from .const import (
     CONF_MIN_TEMP,
     CONF_STEP,
     CONF_TARGET_TEMP,
+    CONF_WRITE_REGISTERS,
     DataType,
 )
 from .modbus import ModbusHub
@@ -106,6 +107,7 @@ class ModbusThermostat(BaseStructPlatform, RestoreEntity, ClimateEntity):
             self._attr_hvac_modes = cast(list[HVACMode], [])
             self._attr_hvac_mode = None
             self._hvac_mode_mapping: list[tuple[int, HVACMode]] = []
+            self._hvac_mode_write_type = mode_config[CONF_WRITE_REGISTERS]
             mode_value_config = mode_config[CONF_HVAC_MODE_VALUES]
 
             for hvac_mode_kw, hvac_mode in (
@@ -131,6 +133,7 @@ class ModbusThermostat(BaseStructPlatform, RestoreEntity, ClimateEntity):
 
         if CONF_HVAC_ONOFF_REGISTER in config:
             self._hvac_onoff_register = config[CONF_HVAC_ONOFF_REGISTER]
+            self._hvac_onoff_write_type = config[CONF_WRITE_REGISTERS]
             if HVACMode.OFF not in self._attr_hvac_modes:
                 self._attr_hvac_modes.append(HVACMode.OFF)
         else:
@@ -147,23 +150,39 @@ class ModbusThermostat(BaseStructPlatform, RestoreEntity, ClimateEntity):
         """Set new target hvac mode."""
         if self._hvac_onoff_register is not None:
             # Turn HVAC Off by writing 0 to the On/Off register, or 1 otherwise.
-            await self._hub.async_pymodbus_call(
-                self._slave,
-                self._hvac_onoff_register,
-                0 if hvac_mode == HVACMode.OFF else 1,
-                CALL_TYPE_WRITE_REGISTER,
-            )
+            if self._hvac_onoff_write_type:
+                await self._hub.async_pymodbus_call(
+                    self._slave,
+                    self._hvac_onoff_register,
+                    [0 if hvac_mode == HVACMode.OFF else 1],
+                    CALL_TYPE_WRITE_REGISTERS,
+                )
+            else:
+                await self._hub.async_pymodbus_call(
+                    self._slave,
+                    self._hvac_onoff_register,
+                    0 if hvac_mode == HVACMode.OFF else 1,
+                    CALL_TYPE_WRITE_REGISTER,
+                )
 
         if self._hvac_mode_register is not None:
             # Write a value to the mode register for the desired mode.
             for value, mode in self._hvac_mode_mapping:
                 if mode == hvac_mode:
-                    await self._hub.async_pymodbus_call(
-                        self._slave,
-                        self._hvac_mode_register,
-                        value,
-                        CALL_TYPE_WRITE_REGISTER,
-                    )
+                    if self._hvac_mode_write_type:
+                        await self._hub.async_pymodbus_call(
+                            self._slave,
+                            self._hvac_mode_register,
+                            [value],
+                            CALL_TYPE_WRITE_REGISTERS,
+                        )
+                    else:
+                        await self._hub.async_pymodbus_call(
+                            self._slave,
+                            self._hvac_mode_register,
+                            value,
+                            CALL_TYPE_WRITE_REGISTER,
+                        )
                     break
 
         await self.async_update()
diff --git a/homeassistant/components/modbus/const.py b/homeassistant/components/modbus/const.py
index b7fcfee9053..4191e1df56f 100644
--- a/homeassistant/components/modbus/const.py
+++ b/homeassistant/components/modbus/const.py
@@ -65,6 +65,7 @@ CONF_HVAC_MODE_HEAT_COOL = "state_heat_cool"
 CONF_HVAC_MODE_AUTO = "state_auto"
 CONF_HVAC_MODE_DRY = "state_dry"
 CONF_HVAC_MODE_FAN_ONLY = "state_fan_only"
+CONF_WRITE_REGISTERS = "write_registers"
 CONF_VERIFY = "verify"
 CONF_VERIFY_REGISTER = "verify_register"
 CONF_VERIFY_STATE = "verify_state"