diff --git a/custom_components/thermia/manifest.json b/custom_components/thermia/manifest.json
index 3db00aa..12a8ef6 100644
--- a/custom_components/thermia/manifest.json
+++ b/custom_components/thermia/manifest.json
@@ -11,7 +11,7 @@
   "iot_class": "cloud_polling",
   "issue_tracker": "https://github.com/klejejs/ha-thermia-heat-pump-integration/issues",
   "requirements": [
-    "ThermiaOnlineAPI==3.17.0"
+    "ThermiaOnlineAPI==3.18.0"
   ],
   "version": "1.0"
 }
diff --git a/custom_components/thermia/sensor.py b/custom_components/thermia/sensor.py
index b46342f..cb6bea3 100644
--- a/custom_components/thermia/sensor.py
+++ b/custom_components/thermia/sensor.py
@@ -220,6 +220,22 @@ async def async_setup_entry(
                 )
             )
 
+        if heat_pump.buffer_tank_temperature is not None:
+            hass_thermia_sensors.append(
+                ThermiaGenericSensor(
+                    coordinator,
+                    idx,
+                    "is_online",
+                    "Buffer Tank Temperature",
+                    MDI_TEMPERATURE_ICON,
+                    EntityCategory.DIAGNOSTIC,
+                    "temperature",
+                    "measurement",
+                    "buffer_tank_temperature",
+                    TEMP_CELSIUS,
+                )
+            )
+
         ###########################################################################
         # Operational status data
         ###########################################################################