diff --git a/custom_components/xiaomi_home/miot/specs/custom_service.json b/custom_components/xiaomi_home/miot/specs/custom_service.json
index 70cc46c..43f278b 100644
--- a/custom_components/xiaomi_home/miot/specs/custom_service.json
+++ b/custom_components/xiaomi_home/miot/specs/custom_service.json
@@ -55,5 +55,27 @@
                 ]
             }
         ]
+    },
+    "urn:miot-spec-v2:device:water-heater:0000A02A:zimi-h03": {
+        "new": [
+            {
+                "iid": 2,
+                "type": "urn:miot-spec-v2:service:switch:0000780C:zimi-h03:1",
+                "description": "Heat Water",
+                "properties": [
+                    {
+                        "iid": 6,
+                        "type": "urn:miot-spec-v2:property:on:00000006:zimi-h03:1",
+                        "description": "Switch Status",
+                        "format": "bool",
+                        "access": [
+                            "read",
+                            "write",
+                            "notify"
+                        ]
+                    }
+                ]
+            }
+        ]
     }
 }
\ No newline at end of file