diff --git a/homeassistant/components/vallox/__init__.py b/homeassistant/components/vallox/__init__.py
index fcda7227945..aeb9e59e286 100644
--- a/homeassistant/components/vallox/__init__.py
+++ b/homeassistant/components/vallox/__init__.py
@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+from datetime import date
 import ipaddress
 import logging
 from typing import Any, NamedTuple
@@ -9,7 +10,10 @@ from uuid import UUID
 
 from vallox_websocket_api import PROFILE as VALLOX_PROFILE, Vallox
 from vallox_websocket_api.exceptions import ValloxApiException
-from vallox_websocket_api.vallox import get_uuid as calculate_uuid
+from vallox_websocket_api.vallox import (
+    get_next_filter_change_date as calculate_next_filter_change_date,
+    get_uuid as calculate_uuid,
+)
 import voluptuous as vol
 
 from homeassistant.config_entries import SOURCE_IMPORT, ConfigEntry
@@ -117,6 +121,15 @@ class ValloxState:
             raise ValueError
         return uuid
 
+    def get_next_filter_change_date(self) -> date | None:
+        """Return the next filter change date."""
+        next_filter_change_date = calculate_next_filter_change_date(self.metric_cache)
+
+        if not isinstance(next_filter_change_date, date):
+            return None
+
+        return next_filter_change_date
+
 
 class ValloxDataUpdateCoordinator(DataUpdateCoordinator):
     """The DataUpdateCoordinator for Vallox."""
diff --git a/homeassistant/components/vallox/manifest.json b/homeassistant/components/vallox/manifest.json
index aed87e9239d..71b0750e2f2 100644
--- a/homeassistant/components/vallox/manifest.json
+++ b/homeassistant/components/vallox/manifest.json
@@ -2,7 +2,7 @@
   "domain": "vallox",
   "name": "Vallox",
   "documentation": "https://www.home-assistant.io/integrations/vallox",
-  "requirements": ["vallox-websocket-api==2.9.0"],
+  "requirements": ["vallox-websocket-api==2.11.0"],
   "codeowners": ["@andre-richter", "@slovdahl", "@viiru-"],
   "config_flow": true,
   "iot_class": "local_polling",
diff --git a/homeassistant/components/vallox/sensor.py b/homeassistant/components/vallox/sensor.py
index 44dfb56fafc..eece054c82e 100644
--- a/homeassistant/components/vallox/sensor.py
+++ b/homeassistant/components/vallox/sensor.py
@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import datetime, timedelta
+from datetime import datetime, time
 
 from homeassistant.components.sensor import (
     SensorDeviceClass,
@@ -20,7 +20,7 @@ from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 from homeassistant.helpers.typing import StateType
 from homeassistant.helpers.update_coordinator import CoordinatorEntity
-from homeassistant.util import dt as dt_util
+from homeassistant.util import dt
 
 from . import ValloxDataUpdateCoordinator
 from .const import (
@@ -95,18 +95,15 @@ class ValloxFilterRemainingSensor(ValloxSensor):
     @property
     def native_value(self) -> StateType | datetime:
         """Return the value reported by the sensor."""
-        super_native_value = super().native_value
+        next_filter_change_date = self.coordinator.data.get_next_filter_change_date()
 
-        if not isinstance(super_native_value, (int, float)):
+        if next_filter_change_date is None:
             return None
 
-        # Since only a delta of days is received from the device, fix the time so the timestamp does
-        # not change with every update.
-        days_remaining = float(super_native_value)
-        days_remaining_delta = timedelta(days=days_remaining)
-        now = datetime.utcnow().replace(hour=13, minute=0, second=0, microsecond=0)
-
-        return (now + days_remaining_delta).astimezone(dt_util.UTC)
+        return datetime.combine(
+            next_filter_change_date,
+            time(hour=13, minute=0, second=0, tzinfo=dt.DEFAULT_TIME_ZONE),
+        )
 
 
 class ValloxCellStateSensor(ValloxSensor):
@@ -150,7 +147,6 @@ SENSORS: tuple[ValloxSensorEntityDescription, ...] = (
     ValloxSensorEntityDescription(
         key="remaining_time_for_filter",
         name="Remaining Time For Filter",
-        metric_key="A_CYC_REMAINING_TIME_FOR_FILTER",
         device_class=SensorDeviceClass.TIMESTAMP,
         sensor_type=ValloxFilterRemainingSensor,
     ),
diff --git a/requirements_all.txt b/requirements_all.txt
index 511f8abb7c5..ef0210e3067 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -2425,7 +2425,7 @@ uscisstatus==0.1.1
 uvcclient==0.11.0
 
 # homeassistant.components.vallox
-vallox-websocket-api==2.9.0
+vallox-websocket-api==2.11.0
 
 # homeassistant.components.rdw
 vehicle==0.3.1
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index 926d5e0d6ee..fe0f3a638bf 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -1495,7 +1495,7 @@ url-normalize==1.4.1
 uvcclient==0.11.0
 
 # homeassistant.components.vallox
-vallox-websocket-api==2.9.0
+vallox-websocket-api==2.11.0
 
 # homeassistant.components.rdw
 vehicle==0.3.1
diff --git a/tests/components/vallox/conftest.py b/tests/components/vallox/conftest.py
new file mode 100644
index 00000000000..e7ea6ee6d6e
--- /dev/null
+++ b/tests/components/vallox/conftest.py
@@ -0,0 +1,65 @@
+"""Common utilities for Vallox tests."""
+
+import random
+import string
+from typing import Any
+from unittest.mock import patch
+from uuid import UUID
+
+import pytest
+from vallox_websocket_api.vallox import PROFILE
+
+from homeassistant.components.vallox.const import DOMAIN
+from homeassistant.const import CONF_HOST, CONF_NAME
+from homeassistant.core import HomeAssistant
+
+from tests.common import MockConfigEntry
+
+
+@pytest.fixture
+def mock_entry(hass: HomeAssistant) -> MockConfigEntry:
+    """Create mocked Vallox config entry."""
+    vallox_mock_entry = MockConfigEntry(
+        domain=DOMAIN,
+        data={
+            CONF_HOST: "192.168.100.50",
+            CONF_NAME: "Vallox",
+        },
+    )
+    vallox_mock_entry.add_to_hass(hass)
+
+    return vallox_mock_entry
+
+
+def patch_metrics(metrics: dict[str, Any]):
+    """Patch the Vallox metrics response."""
+    return patch(
+        "homeassistant.components.vallox.Vallox.fetch_metrics",
+        return_value=metrics,
+    )
+
+
+@pytest.fixture(autouse=True)
+def patch_profile_home():
+    """Patch the Vallox profile response."""
+    with patch(
+        "homeassistant.components.vallox.Vallox.get_profile",
+        return_value=PROFILE.HOME,
+    ):
+        yield
+
+
+@pytest.fixture(autouse=True)
+def patch_uuid():
+    """Patch the Vallox entity UUID."""
+    with patch(
+        "homeassistant.components.vallox.calculate_uuid",
+        return_value=_random_uuid(),
+    ):
+        yield
+
+
+def _random_uuid():
+    """Generate a random UUID."""
+    uuid = "".join(random.choices(string.hexdigits, k=32))
+    return UUID(uuid)
diff --git a/tests/components/vallox/test_sensor.py b/tests/components/vallox/test_sensor.py
new file mode 100644
index 00000000000..bd8ecbea905
--- /dev/null
+++ b/tests/components/vallox/test_sensor.py
@@ -0,0 +1,175 @@
+"""Tests for Vallox sensor platform."""
+
+from datetime import datetime, timedelta, tzinfo
+from unittest.mock import patch
+
+import pytest
+
+from homeassistant.core import HomeAssistant
+from homeassistant.util import dt
+
+from .conftest import patch_metrics
+
+from tests.common import MockConfigEntry
+
+ORIG_TZ = dt.DEFAULT_TIME_ZONE
+
+
+@pytest.fixture(autouse=True)
+def reset_tz():
+    """Restore the default TZ after test runs."""
+    yield
+    dt.DEFAULT_TIME_ZONE = ORIG_TZ
+
+
+@pytest.fixture
+def set_tz(request):
+    """Set the default TZ to the one requested."""
+    return request.getfixturevalue(request.param)
+
+
+@pytest.fixture
+def utc() -> tzinfo:
+    """Set the default TZ to UTC."""
+    tz = dt.get_time_zone("UTC")
+    dt.set_default_time_zone(tz)
+    return tz
+
+
+@pytest.fixture
+def helsinki() -> tzinfo:
+    """Set the default TZ to Europe/Helsinki."""
+    tz = dt.get_time_zone("Europe/Helsinki")
+    dt.set_default_time_zone(tz)
+    return tz
+
+
+@pytest.fixture
+def new_york() -> tzinfo:
+    """Set the default TZ to America/New_York."""
+    tz = dt.get_time_zone("America/New_York")
+    dt.set_default_time_zone(tz)
+    return tz
+
+
+def _sensor_to_datetime(sensor):
+    return datetime.fromisoformat(sensor.state)
+
+
+def _now_at_13():
+    return dt.now().timetz().replace(hour=13, minute=0, second=0, microsecond=0)
+
+
+async def test_remaining_filter_returns_timestamp(
+    mock_entry: MockConfigEntry, hass: HomeAssistant
+):
+    """Test that the remaining time for filter sensor returns a timestamp."""
+    # Act
+    with patch(
+        "homeassistant.components.vallox.calculate_next_filter_change_date",
+        return_value=dt.now().date(),
+    ), patch_metrics(metrics={}):
+        await hass.config_entries.async_setup(mock_entry.entry_id)
+        await hass.async_block_till_done()
+
+    # Assert
+    sensor = hass.states.get("sensor.vallox_remaining_time_for_filter")
+    assert sensor.attributes["device_class"] == "timestamp"
+
+
+async def test_remaining_time_for_filter_none_returned_from_vallox(
+    mock_entry: MockConfigEntry, hass: HomeAssistant
+):
+    """Test that the remaining time for filter sensor returns 'unknown' when Vallox returns None."""
+    # Act
+    with patch(
+        "homeassistant.components.vallox.calculate_next_filter_change_date",
+        return_value=None,
+    ), patch_metrics(metrics={}):
+        await hass.config_entries.async_setup(mock_entry.entry_id)
+        await hass.async_block_till_done()
+
+    # Assert
+    sensor = hass.states.get("sensor.vallox_remaining_time_for_filter")
+    assert sensor.state == "unknown"
+
+
+@pytest.mark.parametrize(
+    "set_tz",
+    [
+        "utc",
+        "helsinki",
+        "new_york",
+    ],
+    indirect=True,
+)
+async def test_remaining_time_for_filter_in_the_future(
+    mock_entry: MockConfigEntry, set_tz: tzinfo, hass: HomeAssistant
+):
+    """Test remaining time for filter when Vallox returns a date in the future."""
+    # Arrange
+    remaining_days = 112
+    mocked_filter_end_date = dt.now().date() + timedelta(days=remaining_days)
+
+    # Act
+    with patch(
+        "homeassistant.components.vallox.calculate_next_filter_change_date",
+        return_value=mocked_filter_end_date,
+    ), patch_metrics(metrics={}):
+        await hass.config_entries.async_setup(mock_entry.entry_id)
+        await hass.async_block_till_done()
+
+    # Assert
+    sensor = hass.states.get("sensor.vallox_remaining_time_for_filter")
+    assert _sensor_to_datetime(sensor) == datetime.combine(
+        mocked_filter_end_date,
+        _now_at_13(),
+    )
+
+
+async def test_remaining_time_for_filter_today(
+    mock_entry: MockConfigEntry, hass: HomeAssistant
+):
+    """Test remaining time for filter when Vallox returns today."""
+    # Arrange
+    remaining_days = 0
+    mocked_filter_end_date = dt.now().date() + timedelta(days=remaining_days)
+
+    # Act
+    with patch(
+        "homeassistant.components.vallox.calculate_next_filter_change_date",
+        return_value=mocked_filter_end_date,
+    ), patch_metrics(metrics={}):
+        await hass.config_entries.async_setup(mock_entry.entry_id)
+        await hass.async_block_till_done()
+
+    # Assert
+    sensor = hass.states.get("sensor.vallox_remaining_time_for_filter")
+    assert _sensor_to_datetime(sensor) == datetime.combine(
+        mocked_filter_end_date,
+        _now_at_13(),
+    )
+
+
+async def test_remaining_time_for_filter_in_the_past(
+    mock_entry: MockConfigEntry, hass: HomeAssistant
+):
+    """Test remaining time for filter when Vallox returns a date in the past."""
+    # Arrange
+    remaining_days = -3
+    mocked_filter_end_date = dt.now().date() + timedelta(days=remaining_days)
+
+    # Act
+    with patch(
+        "homeassistant.components.vallox.calculate_next_filter_change_date",
+        return_value=mocked_filter_end_date,
+    ), patch_metrics(metrics={}):
+        await hass.config_entries.async_setup(mock_entry.entry_id)
+        await hass.async_block_till_done()
+
+    # Assert
+    sensor = hass.states.get("sensor.vallox_remaining_time_for_filter")
+    assert _sensor_to_datetime(sensor) == datetime.combine(
+        mocked_filter_end_date,
+        _now_at_13(),
+    )