diff --git a/deployment/configmap.yml b/deployment/configmap.yml
index 325ff27..026a2cb 100644
--- a/deployment/configmap.yml
+++ b/deployment/configmap.yml
@@ -10,6 +10,7 @@ data:
   MQTT_BOX_TOPIC_PREFIXES: |
     {
       "high_temp": "heating/config/high_temp/",
+      "overwrite_window": "heating/overwrite_window",
       "cmd": "heating/command/"
     }
   MQTT_CENTRAL_TOPICS: |
diff --git a/src/main.py b/src/main.py
index a0ef2f6..7e3ee70 100644
--- a/src/main.py
+++ b/src/main.py
@@ -66,7 +66,7 @@ try:
     box_topic_prefixes = json.loads(BOX_TOPIC_PREFIXES_CONFIG)
     
     # Validation: Check if the required keys are present
-    required_keys = {'high_temp', 'cmd'}
+    required_keys = {'high_temp', 'cmd', 'overwrite_window'}
     missing_keys = required_keys - box_topic_prefixes.keys()
     
     if missing_keys:
diff --git a/src/message_processor.py b/src/message_processor.py
index c18c664..04ceeb5 100644
--- a/src/message_processor.py
+++ b/src/message_processor.py
@@ -20,6 +20,7 @@ def prepare_context(box_name, context):
 
     local_context['general_off'] = False
     local_context['maintenance_mode'] = False
+    local_context['overwrite_window'] = False
 
     local_context['window_state'] = {}
     for w in context['boxes'][box_name]['windows']:
@@ -45,6 +46,8 @@ def process_message(box_name, topic_key, payload, context):
                 result = process_high_temp(box_name, context, local_context, payload)
             case [ primary_key ] if primary_key == 'cmd':
                 result = process_cmd(box_name, context, local_context, payload)
+            case [ primary_key ] if primary_key == 'overwrite_window':
+                result = process_overwrite_window(box_name, context, local_context, payload)
             case [ primary_key ] if primary_key == 'general_off':
                 result = process_general_off(box_name, context, local_context, payload)
             case [ primary_key ] if primary_key == 'maintenance_mode':
@@ -74,10 +77,11 @@ def _calculate_output_temperature(local_context):
         local_context['output_temperature'] = local_context['off_temperature']
         return
     # an open window shuts off the heating
-    for w in local_context['window_state'].values():
-        if w == 'open':
-            local_context['output_temperature'] = local_context['off_temperature']
-            return
+    if not local_context['overwrite_window']:
+        for w in local_context['window_state'].values():
+            if w == 'open':
+                local_context['output_temperature'] = local_context['off_temperature']
+                return
     # finally evaluate the mode
     if local_context['mode'] == 'off':
         local_context['output_temperature'] = local_context['off_temperature']
@@ -113,6 +117,11 @@ def process_cmd(box_name, context, local_context, payload):
         logger.error(f"Invalid cmd for {box_name} received: {payload}")
     return (local_context['output_temperature'], False)
 
+def process_overwrite_window(box_name, context, local_context, payload):
+    local_context['overwrite_window'] = (payload.lower() in ('true'))
+    _calculate_output_temperature(local_context)
+    return (local_context['output_temperature'], False)
+
 def process_high_temp(box_name, context, local_context, payload):
     local_context['high_temperature'] = payload
     _calculate_output_temperature(local_context)