diff --git a/homeassistant/components/duco/coordinator.py b/homeassistant/components/duco/coordinator.py
index 94a6bc60025c..899ad0e5a2f9 100644
--- a/homeassistant/components/duco/coordinator.py
+++ b/homeassistant/components/duco/coordinator.py
@@ -51,7 +51,6 @@ class DucoCoordinator(DataUpdateCoordinator[DucoData]):
 
     config_entry: DucoConfigEntry
     board_info: BoardInfo
-    _supports_time_filter_remain: bool
     _configured_node_names: dict[int, str]
 
     def __init__(
@@ -70,7 +69,6 @@ class DucoCoordinator(DataUpdateCoordinator[DucoData]):
         )
         self.client = client
         self._configured_node_names = {}
-        self._supports_time_filter_remain = True
 
     async def _async_load_node_names(self) -> None:
         """Load configured Duco node names during setup."""
@@ -178,12 +176,11 @@ class DucoCoordinator(DataUpdateCoordinator[DucoData]):
 
         # Heat recovery info only backs the optional filter timer sensor, so
         # failures on this supplemental endpoint should not make the primary
-        # node entities unavailable.
+        # node entities unavailable. A None result leaves the sensor absent
+        # but keeps the helper pollable so data can appear on a later refresh.
         time_filter_remain = None
-        if self._supports_time_filter_remain:
-            with suppress(DucoError):
-                time_filter_remain = await self.client.async_get_time_filter_remaining()
-                self._supports_time_filter_remain = time_filter_remain is not None
+        with suppress(DucoError):
+            time_filter_remain = await self.client.async_get_time_filter_remaining()
 
         ventilation_temperatures = (
             self.data.ventilation_temperatures if self.data else None
diff --git a/tests/components/duco/test_sensor.py b/tests/components/duco/test_sensor.py
index 0ab867c271d8..9cf809fc9878 100644
--- a/tests/components/duco/test_sensor.py
+++ b/tests/components/duco/test_sensor.py
@@ -251,14 +251,14 @@ async def test_lan_info_failures_keep_node_entities_available(
     assert state.state == "-60"
 
 
-async def test_time_filter_remaining_missing_skips_sensor_creation(
+async def test_time_filter_remaining_missing_is_retried(
     hass: HomeAssistant,
     mock_config_entry: MockConfigEntry,
     mock_duco_client: AsyncMock,
     mock_sensor_nodes: list[Node],
     freezer: FrozenDateTimeFactory,
 ) -> None:
-    """Test the filter timer sensor is not created when unsupported."""
+    """Test a missing filter timer does not create the sensor but is retried."""
     mock_duco_client.async_get_nodes.return_value = mock_sensor_nodes
 
     mock_duco_client.async_get_time_filter_remaining = AsyncMock(
@@ -273,7 +273,10 @@ async def test_time_filter_remaining_missing_skips_sensor_creation(
     async_fire_time_changed(hass)
     await hass.async_block_till_done(wait_background_tasks=True)
 
-    assert hass.states.get(FILTER_REMAINING_ENTITY_ID) is None
+    assert mock_duco_client.async_get_time_filter_remaining.await_count == 2
+    state = hass.states.get(FILTER_REMAINING_ENTITY_ID)
+    assert state is not None
+    assert state.state == "180"
 
 
 async def test_empty_ventilation_temperatures_are_retried(