diff --git a/homeassistant/components/modbus/binary_sensor.py b/homeassistant/components/modbus/binary_sensor.py
index cd336ba4f73..979888d0a19 100644
--- a/homeassistant/components/modbus/binary_sensor.py
+++ b/homeassistant/components/modbus/binary_sensor.py
@@ -129,7 +129,7 @@ class ModbusBinarySensor(BinarySensorEntity):
     async def async_added_to_hass(self):
         """Handle entity which will be added."""
         async_track_time_interval(
-            self.hass, lambda arg: self._update(), self._scan_interval
+            self.hass, lambda arg: self.update(), self._scan_interval
         )
 
     @property
@@ -162,7 +162,7 @@ class ModbusBinarySensor(BinarySensorEntity):
         """Return True if entity is available."""
         return self._available
 
-    def _update(self):
+    def update(self):
         """Update the state of the sensor."""
         if self._input_type == CALL_TYPE_COIL:
             result = self._hub.read_coils(self._slave, self._address, 1)
diff --git a/homeassistant/components/modbus/climate.py b/homeassistant/components/modbus/climate.py
index 7d326407c3b..d98cda3ed43 100644
--- a/homeassistant/components/modbus/climate.py
+++ b/homeassistant/components/modbus/climate.py
@@ -133,7 +133,7 @@ class ModbusThermostat(ClimateEntity):
     async def async_added_to_hass(self):
         """Handle entity which will be added."""
         async_track_time_interval(
-            self.hass, lambda arg: self._update(), self._scan_interval
+            self.hass, lambda arg: self.update(), self._scan_interval
         )
 
     @property
@@ -214,14 +214,14 @@ class ModbusThermostat(ClimateEntity):
             self._target_temperature_register,
             register_value,
         )
-        self._update()
+        self.update()
 
     @property
     def available(self) -> bool:
         """Return True if entity is available."""
         return self._available
 
-    def _update(self):
+    def update(self):
         """Update Target & Current Temperature."""
         self._target_temperature = self._read_register(
             CALL_TYPE_REGISTER_HOLDING, self._target_temperature_register
diff --git a/homeassistant/components/modbus/cover.py b/homeassistant/components/modbus/cover.py
index a0deba9d732..7d9bf9e2e45 100644
--- a/homeassistant/components/modbus/cover.py
+++ b/homeassistant/components/modbus/cover.py
@@ -107,7 +107,7 @@ class ModbusCover(CoverEntity, RestoreEntity):
             self._value = state.state
 
         async_track_time_interval(
-            self.hass, lambda arg: self._update(), self._scan_interval
+            self.hass, lambda arg: self.update(), self._scan_interval
         )
 
     @property
@@ -161,7 +161,7 @@ class ModbusCover(CoverEntity, RestoreEntity):
         else:
             self._write_register(self._state_open)
 
-        self._update()
+        self.update()
 
     def close_cover(self, **kwargs: Any) -> None:
         """Close cover."""
@@ -170,9 +170,9 @@ class ModbusCover(CoverEntity, RestoreEntity):
         else:
             self._write_register(self._state_closed)
 
-        self._update()
+        self.update()
 
-    def _update(self):
+    def update(self):
         """Update the state of the cover."""
         if self._coil is not None and self._status_register is None:
             self._value = self._read_coil()
diff --git a/homeassistant/components/modbus/sensor.py b/homeassistant/components/modbus/sensor.py
index 81b54cb62e1..c1a33c41f6d 100644
--- a/homeassistant/components/modbus/sensor.py
+++ b/homeassistant/components/modbus/sensor.py
@@ -229,7 +229,7 @@ class ModbusRegisterSensor(RestoreEntity, SensorEntity):
             self._value = state.state
 
         async_track_time_interval(
-            self.hass, lambda arg: self._update(), self._scan_interval
+            self.hass, lambda arg: self.update(), self._scan_interval
         )
 
     @property
@@ -282,7 +282,7 @@ class ModbusRegisterSensor(RestoreEntity, SensorEntity):
             registers.reverse()
         return registers
 
-    def _update(self):
+    def update(self):
         """Update the state of the sensor."""
         if self._register_type == CALL_TYPE_REGISTER_INPUT:
             result = self._hub.read_input_registers(
diff --git a/homeassistant/components/modbus/switch.py b/homeassistant/components/modbus/switch.py
index 3a74b5d14e1..6fff8c1d373 100644
--- a/homeassistant/components/modbus/switch.py
+++ b/homeassistant/components/modbus/switch.py
@@ -99,7 +99,7 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
 
         if self._verify_active:
             async_track_time_interval(
-                self.hass, lambda arg: self._update(), self._scan_interval
+                self.hass, lambda arg: self.update(), self._scan_interval
             )
 
     @property
@@ -132,7 +132,7 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
         else:
             self._available = True
             if self._verify_active:
-                self._update()
+                self.update()
             else:
                 self._is_on = True
                 self.schedule_update_ha_state()
@@ -146,12 +146,12 @@ class ModbusSwitch(SwitchEntity, RestoreEntity):
         else:
             self._available = True
             if self._verify_active:
-                self._update()
+                self.update()
             else:
                 self._is_on = False
                 self.schedule_update_ha_state()
 
-    def _update(self):
+    def update(self):
         """Update the entity state."""
         if not self._verify_active:
             return
diff --git a/tests/components/modbus/conftest.py b/tests/components/modbus/conftest.py
index de30e690bba..d3ae1286ef1 100644
--- a/tests/components/modbus/conftest.py
+++ b/tests/components/modbus/conftest.py
@@ -201,3 +201,21 @@ async def base_config_test(
         config_modbus=config_modbus,
         expect_init_to_fail=expect_init_to_fail,
     )
+
+
+async def prepare_service_update(hass, config):
+    """Run test for service write_coil."""
+
+    config_modbus = {
+        DOMAIN: {
+            CONF_NAME: DEFAULT_HUB,
+            CONF_TYPE: "tcp",
+            CONF_HOST: "modbusTest",
+            CONF_PORT: 5001,
+            **config,
+        },
+    }
+    assert await async_setup_component(hass, DOMAIN, config_modbus)
+    await hass.async_block_till_done()
+    assert await async_setup_component(hass, "homeassistant", {})
+    await hass.async_block_till_done()
diff --git a/tests/components/modbus/test_modbus_binary_sensor.py b/tests/components/modbus/test_modbus_binary_sensor.py
index 4ce423b2f16..27821c170e1 100644
--- a/tests/components/modbus/test_modbus_binary_sensor.py
+++ b/tests/components/modbus/test_modbus_binary_sensor.py
@@ -19,7 +19,7 @@ from homeassistant.const import (
     STATE_UNAVAILABLE,
 )
 
-from .conftest import base_config_test, base_test
+from .conftest import ReadResult, base_config_test, base_test, prepare_service_update
 
 
 @pytest.mark.parametrize("do_discovery", [False, True])
@@ -99,3 +99,34 @@ async def test_all_binary_sensor(hass, do_type, regs, expected):
         scan_interval=5,
     )
     assert state == expected
+
+
+async def test_service_binary_sensor_update(hass, mock_pymodbus):
+    """Run test for service homeassistant.update_entity."""
+
+    entity_id = "binary_sensor.test"
+    config = {
+        CONF_BINARY_SENSORS: [
+            {
+                CONF_NAME: "test",
+                CONF_ADDRESS: 1234,
+                CONF_INPUT_TYPE: CALL_TYPE_COIL,
+            }
+        ]
+    }
+    mock_pymodbus.read_coils.return_value = ReadResult([0x00])
+    await prepare_service_update(
+        hass,
+        config,
+    )
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    await hass.async_block_till_done()
+    assert hass.states.get(entity_id).state == STATE_OFF
+
+    mock_pymodbus.read_coils.return_value = ReadResult([0x01])
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == STATE_ON
diff --git a/tests/components/modbus/test_modbus_climate.py b/tests/components/modbus/test_modbus_climate.py
index f932817b12e..1e14b255ba5 100644
--- a/tests/components/modbus/test_modbus_climate.py
+++ b/tests/components/modbus/test_modbus_climate.py
@@ -10,7 +10,7 @@ from homeassistant.components.modbus.const import (
 )
 from homeassistant.const import CONF_NAME, CONF_SCAN_INTERVAL, CONF_SLAVE
 
-from .conftest import base_config_test, base_test
+from .conftest import ReadResult, base_config_test, base_test, prepare_service_update
 
 
 @pytest.mark.parametrize(
@@ -76,3 +76,28 @@ async def test_temperature_climate(hass, regs, expected):
         scan_interval=5,
     )
     assert state == expected
+
+
+async def test_service_climate_update(hass, mock_pymodbus):
+    """Run test for service homeassistant.update_entity."""
+
+    entity_id = "climate.test"
+    config = {
+        CONF_CLIMATES: [
+            {
+                CONF_NAME: "test",
+                CONF_TARGET_TEMP: 117,
+                CONF_CURRENT_TEMP: 117,
+                CONF_SLAVE: 10,
+            }
+        ]
+    }
+    mock_pymodbus.read_input_registers.return_value = ReadResult([0x00])
+    await prepare_service_update(
+        hass,
+        config,
+    )
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == "auto"
diff --git a/tests/components/modbus/test_modbus_cover.py b/tests/components/modbus/test_modbus_cover.py
index 957f4b28c75..09d23ebf8bd 100644
--- a/tests/components/modbus/test_modbus_cover.py
+++ b/tests/components/modbus/test_modbus_cover.py
@@ -4,7 +4,12 @@ import logging
 import pytest
 
 from homeassistant.components.cover import DOMAIN as COVER_DOMAIN
-from homeassistant.components.modbus.const import CALL_TYPE_COIL, CONF_REGISTER
+from homeassistant.components.modbus.const import (
+    CALL_TYPE_COIL,
+    CALL_TYPE_REGISTER_HOLDING,
+    CONF_REGISTER,
+    CONF_STATUS_REGISTER_TYPE,
+)
 from homeassistant.const import (
     CONF_COVERS,
     CONF_NAME,
@@ -14,7 +19,7 @@ from homeassistant.const import (
     STATE_OPEN,
 )
 
-from .conftest import base_config_test, base_test
+from .conftest import ReadResult, base_config_test, base_test, prepare_service_update
 
 
 @pytest.mark.parametrize(
@@ -168,3 +173,32 @@ async def test_unsupported_config_cover(hass, read_type, caplog):
 
     assert len(caplog.records) == 1
     assert caplog.records[0].levelname == "WARNING"
+
+
+async def test_service_cover_update(hass, mock_pymodbus):
+    """Run test for service homeassistant.update_entity."""
+
+    entity_id = "cover.test"
+    config = {
+        CONF_COVERS: [
+            {
+                CONF_NAME: "test",
+                CONF_REGISTER: 1234,
+                CONF_STATUS_REGISTER_TYPE: CALL_TYPE_REGISTER_HOLDING,
+            }
+        ]
+    }
+    mock_pymodbus.read_holding_registers.return_value = ReadResult([0x00])
+    await prepare_service_update(
+        hass,
+        config,
+    )
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == STATE_CLOSED
+    mock_pymodbus.read_holding_registers.return_value = ReadResult([0x01])
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == STATE_OPEN
diff --git a/tests/components/modbus/test_modbus_sensor.py b/tests/components/modbus/test_modbus_sensor.py
index b8ab10953c8..c83eab0b3d6 100644
--- a/tests/components/modbus/test_modbus_sensor.py
+++ b/tests/components/modbus/test_modbus_sensor.py
@@ -40,7 +40,7 @@ from homeassistant.const import (
 )
 from homeassistant.core import State
 
-from .conftest import base_config_test, base_test
+from .conftest import ReadResult, base_config_test, base_test, prepare_service_update
 
 
 @pytest.mark.parametrize(
@@ -621,3 +621,32 @@ async def test_swap_sensor_wrong_config(hass, caplog, swap_type):
         expect_init_to_fail=True,
     )
     assert caplog.messages[-1].startswith("Error in sensor " + sensor_name + " swap")
+
+
+async def test_service_sensor_update(hass, mock_pymodbus):
+    """Run test for service homeassistant.update_entity."""
+
+    entity_id = "sensor.test"
+    config = {
+        CONF_SENSORS: [
+            {
+                CONF_NAME: "test",
+                CONF_ADDRESS: 1234,
+                CONF_INPUT_TYPE: CALL_TYPE_REGISTER_INPUT,
+            }
+        ]
+    }
+    mock_pymodbus.read_input_registers.return_value = ReadResult([27])
+    await prepare_service_update(
+        hass,
+        config,
+    )
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == "27"
+    mock_pymodbus.read_input_registers.return_value = ReadResult([32])
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == "32"
diff --git a/tests/components/modbus/test_modbus_switch.py b/tests/components/modbus/test_modbus_switch.py
index bc96127cbd6..f247bb4b148 100644
--- a/tests/components/modbus/test_modbus_switch.py
+++ b/tests/components/modbus/test_modbus_switch.py
@@ -25,7 +25,7 @@ from homeassistant.const import (
     STATE_ON,
 )
 
-from .conftest import base_config_test, base_test
+from .conftest import ReadResult, base_config_test, base_test, prepare_service_update
 
 
 @pytest.mark.parametrize(
@@ -220,3 +220,33 @@ async def test_register_state_switch(hass, regs, expected):
         scan_interval=5,
     )
     assert state == expected
+
+
+async def test_service_switch_update(hass, mock_pymodbus):
+    """Run test for service homeassistant.update_entity."""
+
+    entity_id = "switch.test"
+    config = {
+        CONF_SWITCHES: [
+            {
+                CONF_NAME: "test",
+                CONF_ADDRESS: 1234,
+                CONF_WRITE_TYPE: CALL_TYPE_COIL,
+                CONF_VERIFY: {},
+            }
+        ]
+    }
+    mock_pymodbus.read_coils.return_value = ReadResult([0x01])
+    await prepare_service_update(
+        hass,
+        config,
+    )
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == STATE_ON
+    mock_pymodbus.read_coils.return_value = ReadResult([0x00])
+    await hass.services.async_call(
+        "homeassistant", "update_entity", {"entity_id": entity_id}, blocking=True
+    )
+    assert hass.states.get(entity_id).state == STATE_OFF