diff --git a/homeassistant/components/litterrobot/coordinator.py b/homeassistant/components/litterrobot/coordinator.py
index 0076eae007c..ba40602cee1 100644
--- a/homeassistant/components/litterrobot/coordinator.py
+++ b/homeassistant/components/litterrobot/coordinator.py
@@ -46,11 +46,18 @@ class LitterRobotDataUpdateCoordinator(DataUpdateCoordinator[None]):
 
     async def _async_update_data(self) -> None:
         """Update all device states from the Litter-Robot API."""
-        await self.account.refresh_robots()
-        await self.account.load_pets()
-        for pet in self.account.pets:
-            # Need to fetch weight history for `get_visits_since`
-            await pet.fetch_weight_history()
+        try:
+            await self.account.refresh_robots()
+            await self.account.load_pets()
+            for pet in self.account.pets:
+                # Need to fetch weight history for `get_visits_since`
+                await pet.fetch_weight_history()
+        except LitterRobotLoginException as ex:
+            raise ConfigEntryAuthFailed("Invalid credentials") from ex
+        except LitterRobotException as ex:
+            raise UpdateFailed(
+                f"Unable to fetch data from the Whisker API: {ex}"
+            ) from ex
 
     async def _async_setup(self) -> None:
         """Set up the coordinator."""
diff --git a/homeassistant/components/litterrobot/quality_scale.yaml b/homeassistant/components/litterrobot/quality_scale.yaml
index 172e3ce1f27..8c135d69b0d 100644
--- a/homeassistant/components/litterrobot/quality_scale.yaml
+++ b/homeassistant/components/litterrobot/quality_scale.yaml
@@ -29,9 +29,9 @@ rules:
     status: done
     comment: No options to configure
   docs-installation-parameters: done
-  entity-unavailable: todo
+  entity-unavailable: done
   integration-owner: done
-  log-when-unavailable: todo
+  log-when-unavailable: done
   parallel-updates: done
   reauthentication-flow: done
   test-coverage:
diff --git a/tests/components/litterrobot/test_coordinator.py b/tests/components/litterrobot/test_coordinator.py
new file mode 100644
index 00000000000..2ff7fee4d9d
--- /dev/null
+++ b/tests/components/litterrobot/test_coordinator.py
@@ -0,0 +1,81 @@
+"""Tests for the Litter-Robot coordinator."""
+
+from unittest.mock import MagicMock
+
+from freezegun.api import FrozenDateTimeFactory
+from pylitterbot.exceptions import LitterRobotException, LitterRobotLoginException
+
+from homeassistant.components.litterrobot.const import DOMAIN
+from homeassistant.components.litterrobot.coordinator import UPDATE_INTERVAL
+from homeassistant.components.vacuum import DOMAIN as VACUUM_DOMAIN
+from homeassistant.config_entries import SOURCE_REAUTH
+from homeassistant.const import STATE_UNAVAILABLE
+from homeassistant.core import HomeAssistant
+
+from .common import VACUUM_ENTITY_ID
+from .conftest import setup_integration
+
+from tests.common import async_fire_time_changed
+
+
+async def test_coordinator_update_error(
+    hass: HomeAssistant,
+    mock_account: MagicMock,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test entities become unavailable when coordinator update fails."""
+    await setup_integration(hass, mock_account, VACUUM_DOMAIN)
+
+    assert (state := hass.states.get(VACUUM_ENTITY_ID))
+    assert state.state != STATE_UNAVAILABLE
+
+    # Simulate an API error during update
+    mock_account.refresh_robots.side_effect = LitterRobotException("Unable to connect")
+    freezer.tick(UPDATE_INTERVAL)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert (state := hass.states.get(VACUUM_ENTITY_ID))
+    assert state.state == STATE_UNAVAILABLE
+
+    # Recover
+    mock_account.refresh_robots.side_effect = None
+    freezer.tick(UPDATE_INTERVAL)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert (state := hass.states.get(VACUUM_ENTITY_ID))
+    assert state.state != STATE_UNAVAILABLE
+
+
+async def test_coordinator_update_auth_error(
+    hass: HomeAssistant,
+    mock_account: MagicMock,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test reauthentication flow is triggered on login error during update."""
+    entry = await setup_integration(hass, mock_account, VACUUM_DOMAIN)
+
+    assert (state := hass.states.get(VACUUM_ENTITY_ID))
+    assert state.state != STATE_UNAVAILABLE
+
+    # Simulate an authentication error during update
+    mock_account.refresh_robots.side_effect = LitterRobotLoginException(
+        "Invalid credentials"
+    )
+    freezer.tick(UPDATE_INTERVAL)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert (state := hass.states.get(VACUUM_ENTITY_ID))
+    assert state.state == STATE_UNAVAILABLE
+
+    # Ensure a reauthentication flow was triggered
+    flows = hass.config_entries.flow.async_progress()
+    assert len(flows) == 1
+
+    flow = flows[0]
+    assert flow["step_id"] == "reauth_confirm"
+    assert flow["handler"] == DOMAIN
+    assert flow["context"].get("source") == SOURCE_REAUTH
+    assert flow["context"].get("entry_id") == entry.entry_id