diff --git a/Climate/bosch_bth-ra_control.yaml b/Climate/bosch_bth-ra_control.yaml
index a0edd26..8f0f9a6 100644
--- a/Climate/bosch_bth-ra_control.yaml
+++ b/Climate/bosch_bth-ra_control.yaml
@@ -303,13 +303,17 @@ variables:
        (override_reset_duration.minutes | default(0) | int) * 60 + 
        (override_reset_duration.seconds | default(0) | int) if override_reset_duration is mapping else 0 }}
   override_last_change: >
-    {{ as_datetime(states[setpoint_change_source_entity].last_updated) if setpoint_change_source_entity and 
+    {{ states[setpoint_change_source_entity].last_updated if setpoint_change_source_entity and 
        states(setpoint_change_source_entity) not in ['unknown', 'unavailable', none] else none }}
   override_duration_exceeded: >
-    {% set last_change = override_last_change %}
-    {% if last_change != none and last_change is not string and override_reset_duration_seconds > 0 and setpoint_change_source_entity and states(setpoint_change_source_entity) == 'manual' %}
-      {% set elapsed = (now() - last_change).total_seconds() %}
-      {{ elapsed > override_reset_duration_seconds }}
+    {% if override_last_change != none and override_reset_duration_seconds > 0 and setpoint_change_source_entity and states(setpoint_change_source_entity) == 'manual' %}
+      {% set last_change = as_datetime(override_last_change) %}
+      {% if last_change != none %}
+        {% set elapsed = (now() - last_change).total_seconds() %}
+        {{ elapsed > override_reset_duration_seconds }}
+      {% else %}
+        false
+      {% endif %}
     {% else %}
       false
     {% endif %}