diff --git a/custom_components/myenergi/diagnostics.py b/custom_components/myenergi/diagnostics.py
index 63364d4..3680e00 100644
--- a/custom_components/myenergi/diagnostics.py
+++ b/custom_components/myenergi/diagnostics.py
@@ -5,9 +5,6 @@
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import HomeAssistant
-from homeassistant.helpers.device_registry import DeviceEntry
-from pymyenergi.client import MyenergiClient
-from pymyenergi.connection import Connection
 
 from .const import DOMAIN
 
@@ -18,7 +15,6 @@ async def async_get_config_entry_diagnostics(
     """Return diagnostics for a config entry."""
     data = {}
     coordinator = hass.data[DOMAIN][entry.entry_id]
-    devices = []
     # Don't cause a refresh when fetching devices
     all_devices = await coordinator.client.get_devices("all", False)
     for device in all_devices:
diff --git a/custom_components/myenergi/sensor.py b/custom_components/myenergi/sensor.py
index 577bdb4..f215fa2 100644
--- a/custom_components/myenergi/sensor.py
+++ b/custom_components/myenergi/sensor.py
@@ -305,6 +305,16 @@ async def async_setup_entry(hass, entry, async_add_devices):
 
         # Sensors common to Zapi and Eddi
         if device.kind in [ZAPPI, EDDI]:
+            sensors.append(
+                MyenergiSensor(
+                    coordinator,
+                    device,
+                    entry,
+                    create_meta(
+                        "Number of phases", "num_phases", ENTITY_CATEGORY_DIAGNOSTIC
+                    ),
+                )
+            )
             sensors.append(
                 MyenergiSensor(
                     coordinator,
diff --git a/tests/test_services.py b/tests/test_services.py
index 0d6671f..3d689b8 100644
--- a/tests/test_services.py
+++ b/tests/test_services.py
@@ -92,9 +92,7 @@ async def test_stop_boost(
     assert mock_zappi_stop_boost.call_count == 1
 
 
-async def test_unlock(
-    hass: HomeAssistant, mock_zappi_unlock: MagicMock
-) -> None:
+async def test_unlock(hass: HomeAssistant, mock_zappi_unlock: MagicMock) -> None:
     """Verify device information includes expected details."""
 
     await setup_mock_myenergi_config_entry(hass)
@@ -109,4 +107,4 @@ async def test_unlock(
     )
     assert mock_zappi_unlock.call_count == 0
     await hass.async_block_till_done()
-    assert mock_zappi_unlock.call_count == 1
\ No newline at end of file
+    assert mock_zappi_unlock.call_count == 1