diff --git a/homeassistant/components/vallox/const.py b/homeassistant/components/vallox/const.py
index 6d12d0bab8e..aba10188bde 100644
--- a/homeassistant/components/vallox/const.py
+++ b/homeassistant/components/vallox/const.py
@@ -37,3 +37,10 @@ VALLOX_PROFILE_TO_STR_REPORTABLE = {
 STR_TO_VALLOX_PROFILE_SETTABLE = {
     value: key for (key, value) in VALLOX_PROFILE_TO_STR_SETTABLE.items()
 }
+
+VALLOX_CELL_STATE_TO_STR = {
+    0: "Heat Recovery",
+    1: "Cool Recovery",
+    2: "Bypass",
+    3: "Defrosting",
+}
diff --git a/homeassistant/components/vallox/sensor.py b/homeassistant/components/vallox/sensor.py
index 2fdfd2cd472..0341153a9ff 100644
--- a/homeassistant/components/vallox/sensor.py
+++ b/homeassistant/components/vallox/sensor.py
@@ -25,7 +25,13 @@ from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType, StateTyp
 from homeassistant.helpers.update_coordinator import CoordinatorEntity
 
 from . import ValloxDataUpdateCoordinator
-from .const import DOMAIN, METRIC_KEY_MODE, MODE_ON, VALLOX_PROFILE_TO_STR_REPORTABLE
+from .const import (
+    DOMAIN,
+    METRIC_KEY_MODE,
+    MODE_ON,
+    VALLOX_CELL_STATE_TO_STR,
+    VALLOX_PROFILE_TO_STR_REPORTABLE,
+)
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -106,6 +112,21 @@ class ValloxFilterRemainingSensor(ValloxSensor):
         return (now + days_remaining_delta).isoformat()
 
 
+class ValloxCellStateSensor(ValloxSensor):
+    """Child class for cell state reporting."""
+
+    @property
+    def native_value(self) -> StateType:
+        """Return the value reported by the sensor."""
+        super_native_value = super().native_value
+
+        if not isinstance(super_native_value, (int, float)):
+            _LOGGER.debug("Value has unexpected type: %s", type(super_native_value))
+            return None
+
+        return VALLOX_CELL_STATE_TO_STR.get(int(super_native_value))
+
+
 @dataclass
 class ValloxSensorEntityDescription(SensorEntityDescription):
     """Describes Vallox sensor entity."""
@@ -137,6 +158,13 @@ SENSORS: tuple[ValloxSensorEntityDescription, ...] = (
         device_class=DEVICE_CLASS_TIMESTAMP,
         sensor_type=ValloxFilterRemainingSensor,
     ),
+    ValloxSensorEntityDescription(
+        key="cell_state",
+        name="Cell State",
+        icon="mdi:swap-horizontal-bold",
+        metric_key="A_CYC_CELL_STATE",
+        sensor_type=ValloxCellStateSensor,
+    ),
     ValloxSensorEntityDescription(
         key="extract_air",
         name="Extract Air",