diff --git a/homeassistant/components/apsystems/number.py b/homeassistant/components/apsystems/number.py
index 6463d10f3e8..b5ed60a7754 100644
--- a/homeassistant/components/apsystems/number.py
+++ b/homeassistant/components/apsystems/number.py
@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+from aiohttp import ClientConnectorError
+
 from homeassistant.components.number import NumberDeviceClass, NumberEntity, NumberMode
 from homeassistant.const import UnitOfPower
 from homeassistant.core import HomeAssistant
@@ -45,7 +47,13 @@ class ApSystemsMaxOutputNumber(ApSystemsEntity, NumberEntity):
 
     async def async_update(self) -> None:
         """Set the state with the value fetched from the inverter."""
-        self._attr_native_value = await self._api.get_max_power()
+        try:
+            status = await self._api.get_max_power()
+        except (TimeoutError, ClientConnectorError):
+            self._attr_available = False
+        else:
+            self._attr_available = True
+            self._attr_native_value = status
 
     async def async_set_native_value(self, value: float) -> None:
         """Set the desired output power."""
diff --git a/tests/components/apsystems/test_number.py b/tests/components/apsystems/test_number.py
index 5868bd3da34..912759b4a17 100644
--- a/tests/components/apsystems/test_number.py
+++ b/tests/components/apsystems/test_number.py
@@ -12,7 +12,7 @@ from homeassistant.components.number import (
     DOMAIN as NUMBER_DOMAIN,
     SERVICE_SET_VALUE,
 )
-from homeassistant.const import ATTR_ENTITY_ID, Platform
+from homeassistant.const import ATTR_ENTITY_ID, STATE_UNAVAILABLE, Platform
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers import entity_registry as er
 
@@ -46,6 +46,17 @@ async def test_number(
     await hass.async_block_till_done()
     state = hass.states.get(entity_id)
     assert state.state == "50"
+    mock_apsystems.get_max_power.side_effect = TimeoutError()
+    await hass.services.async_call(
+        NUMBER_DOMAIN,
+        SERVICE_SET_VALUE,
+        service_data={ATTR_VALUE: 50.1},
+        target={ATTR_ENTITY_ID: entity_id},
+        blocking=True,
+    )
+    await hass.async_block_till_done()
+    state = hass.states.get(entity_id)
+    assert state.state == STATE_UNAVAILABLE
 
 
 @pytest.mark.usefixtures("mock_apsystems")