diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index b44deb32..6f7a42b0 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -60,6 +60,14 @@ Documentation
   5,000 W rating, and that a mode write may not take effect while a TOU
   window is in force. ``device_status.rst``'s Heating Elements notes now
   point at it.
+- **currentInstPower includes the heating elements.** The field
+  table and *Power and Energy Fields* in the protocol reference, and the
+  ``current_inst_power`` field description, said it excludes element
+  power; ``track-energy.rst`` said it includes it. On a 240 V NWP500-65
+  it includes it: element-only minutes read about 5.1 kW, compressor
+  and element together about 5.5 kW, and the tank's heat gain agrees.
+  All four now say so, with the measurement and its limits (one model,
+  240 V only). (#139)
 
 Version 9.4.2 (2026-09-17)
 ==========================
diff --git a/docs/reference/protocol/data_conversions.rst b/docs/reference/protocol/data_conversions.rst
index 7776f61c..f4fa49bc 100644
--- a/docs/reference/protocol/data_conversions.rst
+++ b/docs/reference/protocol/data_conversions.rst
@@ -372,7 +372,7 @@ Power and Energy Fields
    * - ``currentInstPower``
      - None (direct value)
      - W
-     - **Instantaneous power consumption**. Real-time measurement. Does **NOT** include electric heating element power draw. Heat pump only.
+     - **Instantaneous power consumption** of the whole unit, electric heating elements included. Real-time measurement.
    * - ``totalEnergyCapacity``
      - ``x 4`` (see note)
      - Wh
@@ -396,7 +396,22 @@ Power and Energy Fields
    of 7.0. See :doc:`../../explanation/tank-energy`.
 
 .. note::
-   ``currentInstPower`` excludes electric heating element power. If the heater is actively heating with electric elements, the actual power draw will be higher (typically +3755W @ 208V or +5000W @ 240V).
+   ``currentInstPower`` **includes** electric heating element power.
+   Earlier versions of this page said the opposite. One NWP500-65 on
+   240 V, recorded minute by minute from 2025-12-28 to 2026-09-18 against
+   ``compUse``, ``heatUpperUse`` and ``heatLowerUse``, reads:
+
+   * compressor only: median 410 W (101,326 minutes)
+   * upper element only: median 5,191 W (105 minutes)
+   * lower element only: median 5,092 W (76 minutes)
+   * compressor and upper element: median 5,488 W (979 minutes)
+
+   Element-only minutes read the element's 240 V rating, not zero, and
+   compressor-plus-element reads about the sum. The tank's heat gain
+   agrees: divided by this reading it gives 2.8-3.1 with the compressor
+   alone (the COP in :doc:`../../explanation/tank-energy`) and about 1.2
+   with the lower element alone. Other models and 208 V supplies have not
+   been checked.
 
 System Status and Performance Fields
 ------------------------------------
diff --git a/docs/reference/protocol/device_status.rst b/docs/reference/protocol/device_status.rst
index ca3a43ef..cd8425c1 100644
--- a/docs/reference/protocol/device_status.rst
+++ b/docs/reference/protocol/device_status.rst
@@ -171,7 +171,7 @@ This document lists the fields found in the ``status`` object of device status m
    * - ``currentInstPower``
      - integer
      - W
-     - Current instantaneous power consumption in Watts. Does not include heating element power when active.
+     - Current instantaneous power consumption of the whole unit in Watts, heating elements included. On a 240 V NWP500-65 it reads about 410 W with only the compressor running, about 5.1 kW with only an element, and about 5.5 kW with both. See *Power and Energy Fields* in :doc:`data_conversions`.
      - None
    * - ``shutOffValveUse``
      - bool
diff --git a/src/nwp500/models/status.py b/src/nwp500/models/status.py
index d6f71297..5bf4a8f7 100644
--- a/src/nwp500/models/status.py
+++ b/src/nwp500/models/status.py
@@ -276,8 +276,8 @@ class DeviceStatus(NavienBaseModel):
     recirc_error_status: int = Field(description="Recirculation error status")
     current_inst_power: float = Field(
         description=(
-            "Current instantaneous power consumption in Watts. "
-            "Does not include heating element power when active"
+            "Current instantaneous power consumption of the whole unit "
+            "in Watts, including heating element power when active"
         ),
         json_schema_extra={
             "unit_of_measurement": "W",