diff --git a/apps/global/heating.yaml b/apps/global/heating.yaml
index b5f3318..1bb7891 100644
--- a/apps/global/heating.yaml
+++ b/apps/global/heating.yaml
@@ -232,6 +232,7 @@ radiator_heating:
   initial_mode: heat
 
   smart_conditions:
+    unavaibility_result: Failed #if something is unavailable in the expression, the radiator stay off
     local_expressions:
       outdoor_temperature: "sensor.ext_front_temperature < sensor.ext_back_temperature ? sensor.ext_front_temperature : sensor.ext_back_temperature"
     trigger_conditions: binary_sensor.someone_home and outdoor_temperature < self.temperature