diff --git a/docs/DEVICE_STATUS_FIELDS.rst b/docs/DEVICE_STATUS_FIELDS.rst
index 8f58e49..3d7ad51 100644
--- a/docs/DEVICE_STATUS_FIELDS.rst
+++ b/docs/DEVICE_STATUS_FIELDS.rst
@@ -489,6 +489,34 @@ The ``operationMode`` field is an integer that maps to the following modes. Thes
      - Very High
      - Suspends heating to save energy during absences (0-99 days). Only minimal operations like freeze protection and anti-seize are performed. Heating resumes 9 hours before the vacation period ends.
 
+
+Observed Operation Modes (from network traffic analysis)
+--------------------------------------------------------
+
+The following ``operationMode`` values have been observed in status messages from the device. These values appear to correspond to the commanded modes as follows:
+
+.. list-table::
+   :header-rows: 1
+   :widths: 10 30 60
+
+   * - Value
+     - Mode
+     - Notes
+   * - 0
+     - Standby / Vacation
+     - Corresponds to commanded modes ``STANDBY`` (0) and ``VACATION`` (5).
+   * - 32
+     - Heat Pump
+     - Corresponds to commanded mode ``HEAT_PUMP`` (1).
+   * - 64
+     - Energy Saver
+     - Corresponds to commanded mode ``ENERGY_SAVER`` (2).
+   * - 96
+     - High Demand
+     - Corresponds to commanded mode ``HIGH_DEMAND`` (3).
+
+The commanded mode ``ELECTRIC`` (4) has been observed to result in ``operationMode`` values of both 64 and 96 at different times.
+
 Technical Notes
 ---------------
 
diff --git a/src/nwp500/models.py b/src/nwp500/models.py
index 4896f1a..655b031 100644
--- a/src/nwp500/models.py
+++ b/src/nwp500/models.py
@@ -14,15 +14,27 @@
 
 
 class OperationMode(Enum):
-    """Enumeration for the operation modes of the device."""
+    """Enumeration for the operation modes of the device.
 
-    STANDBY = 0  # Device is in standby (e.g., when DHW tank is fully charged)
+    The first set of modes (0-5) are used when commanding the device, while
+    the second set (32, 64, 96) are observed in status messages.
+    """
+
+    # Commanded modes
+    STANDBY = 0
     HEAT_PUMP = 1
     ENERGY_SAVER = 2
     HIGH_DEMAND = 3
     ELECTRIC = 4
     VACATION = 5
 
+    # Observed status modes
+    HEAT_PUMP_MODE = 32
+    HYBRID_EFFICIENCY_MODE = 64
+    HYBRID_BOOST_MODE = 96
+
+    # Aliases
+
 
 class TemperatureUnit(Enum):
     """Enumeration for temperature units."""