diff --git a/homeassistant/components/apsystems/number.py b/homeassistant/components/apsystems/number.py
index 01e991f5188..6463d10f3e8 100644
--- a/homeassistant/components/apsystems/number.py
+++ b/homeassistant/components/apsystems/number.py
@@ -20,7 +20,7 @@ async def async_setup_entry(
 ) -> None:
     """Set up the sensor platform."""
 
-    add_entities([ApSystemsMaxOutputNumber(config_entry.runtime_data)])
+    add_entities([ApSystemsMaxOutputNumber(config_entry.runtime_data)], True)
 
 
 class ApSystemsMaxOutputNumber(ApSystemsEntity, NumberEntity):
diff --git a/tests/components/apsystems/conftest.py b/tests/components/apsystems/conftest.py
index 0feccf21578..7a48ff7db3f 100644
--- a/tests/components/apsystems/conftest.py
+++ b/tests/components/apsystems/conftest.py
@@ -59,6 +59,7 @@ def mock_apsystems() -> Generator[MagicMock]:
             operating=False,
         )
         mock_api.get_device_power_status.return_value = True
+        mock_api.get_max_power.return_value = 666
         yield mock_api
 
 
diff --git a/tests/components/apsystems/snapshots/test_number.ambr b/tests/components/apsystems/snapshots/test_number.ambr
new file mode 100644
index 00000000000..a2b82e23596
--- /dev/null
+++ b/tests/components/apsystems/snapshots/test_number.ambr
@@ -0,0 +1,58 @@
+# serializer version: 1
+# name: test_all_entities[number.mock_title_max_output-entry]
+  EntityRegistryEntrySnapshot({
+    'aliases': set({
+    }),
+    'area_id': None,
+    'capabilities': dict({
+      'max': 1000,
+      'min': 0,
+      'mode': <NumberMode.BOX: 'box'>,
+      'step': 1,
+    }),
+    'config_entry_id': <ANY>,
+    'device_class': None,
+    'device_id': <ANY>,
+    'disabled_by': None,
+    'domain': 'number',
+    'entity_category': None,
+    'entity_id': 'number.mock_title_max_output',
+    'has_entity_name': True,
+    'hidden_by': None,
+    'icon': None,
+    'id': <ANY>,
+    'labels': set({
+    }),
+    'name': None,
+    'options': dict({
+    }),
+    'original_device_class': <NumberDeviceClass.POWER: 'power'>,
+    'original_icon': None,
+    'original_name': 'Max output',
+    'platform': 'apsystems',
+    'previous_unique_id': None,
+    'supported_features': 0,
+    'translation_key': 'max_output',
+    'unique_id': 'MY_SERIAL_NUMBER_output_limit',
+    'unit_of_measurement': <UnitOfPower.WATT: 'W'>,
+  })
+# ---
+# name: test_all_entities[number.mock_title_max_output-state]
+  StateSnapshot({
+    'attributes': ReadOnlyDict({
+      'device_class': 'power',
+      'friendly_name': 'Mock Title Max output',
+      'max': 1000,
+      'min': 0,
+      'mode': <NumberMode.BOX: 'box'>,
+      'step': 1,
+      'unit_of_measurement': <UnitOfPower.WATT: 'W'>,
+    }),
+    'context': <ANY>,
+    'entity_id': 'number.mock_title_max_output',
+    'last_changed': <ANY>,
+    'last_reported': <ANY>,
+    'last_updated': <ANY>,
+    'state': '666',
+  })
+# ---
diff --git a/tests/components/apsystems/test_number.py b/tests/components/apsystems/test_number.py
new file mode 100644
index 00000000000..5868bd3da34
--- /dev/null
+++ b/tests/components/apsystems/test_number.py
@@ -0,0 +1,61 @@
+"""Test the APSystem number module."""
+
+import datetime
+from unittest.mock import AsyncMock, patch
+
+from freezegun.api import FrozenDateTimeFactory
+import pytest
+from syrupy import SnapshotAssertion
+
+from homeassistant.components.number import (
+    ATTR_VALUE,
+    DOMAIN as NUMBER_DOMAIN,
+    SERVICE_SET_VALUE,
+)
+from homeassistant.const import ATTR_ENTITY_ID, Platform
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import entity_registry as er
+
+from . import setup_integration
+
+from tests.common import MockConfigEntry, async_fire_time_changed, snapshot_platform
+
+SCAN_INTERVAL = datetime.timedelta(seconds=30)
+
+
+async def test_number(
+    hass: HomeAssistant,
+    mock_apsystems: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test number command."""
+    await setup_integration(hass, mock_config_entry)
+    entity_id = "number.mock_title_max_output"
+    await hass.services.async_call(
+        NUMBER_DOMAIN,
+        SERVICE_SET_VALUE,
+        service_data={ATTR_VALUE: 50.1},
+        target={ATTR_ENTITY_ID: entity_id},
+        blocking=True,
+    )
+    mock_apsystems.set_max_power.assert_called_once_with(50)
+    mock_apsystems.get_max_power.return_value = 50
+    freezer.tick(SCAN_INTERVAL)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+    state = hass.states.get(entity_id)
+    assert state.state == "50"
+
+
+@pytest.mark.usefixtures("mock_apsystems")
+@patch("homeassistant.components.apsystems.PLATFORMS", [Platform.NUMBER])
+async def test_all_entities(
+    hass: HomeAssistant,
+    snapshot: SnapshotAssertion,
+    mock_config_entry: MockConfigEntry,
+    entity_registry: er.EntityRegistry,
+) -> None:
+    """Test all entities."""
+    await setup_integration(hass, mock_config_entry)
+    await snapshot_platform(hass, entity_registry, snapshot, mock_config_entry.entry_id)