diff --git a/src/modules/selector.cpp b/src/modules/selector.cpp
index 56514da..6c8d5d7 100644
--- a/src/modules/selector.cpp
+++ b/src/modules/selector.cpp
@@ -21,6 +21,7 @@ void Selector::PrepareMoveToPlannedSlot() {
 
 void Selector::PlanHomingMoveForward() {
     state = PlannedHome;
+    plannedHomeTimer = 0; // reset timeout counter when entering PlannedHome
     dbg_logic_P(PSTR("Plan Homing Selector Forward"));
 }
 
@@ -110,6 +111,13 @@ bool Selector::Step() {
             state = HomeForward;
             mm::motion.PlanMove<mm::Selector>(mm::unitToAxisUnit<mm::S_pos_t>(-config::selectorLimits.lenght * 2),
                 mm::unitToAxisUnit<mm::S_speed_t>(mg::globals.SelectorHomingFeedrate_mm_s()));
+        } else if (++plannedHomeTimer >= 30000U) {
+            // Idler did not become homing-valid within ~30 000 main-loop iterations.
+            // This breaks a potential deadlock where the idler is stuck in a non-error
+            // state (e.g. Ready with homingValid==false) that WaitForModulesErrorRecovery
+            // cannot detect.  HomeFailed() transitions selector to HomingFailed, which IS
+            // detected and surfaces an error screen to the user.
+            HomeFailed();
         }
         return false;
     case HomeForward:
diff --git a/src/modules/selector.h b/src/modules/selector.h
index 0fd247c..66ee19e 100644
--- a/src/modules/selector.h
+++ b/src/modules/selector.h
@@ -15,7 +15,8 @@ namespace mm = modules::motion;
 class Selector : public mm::MovableBase {
 public:
     inline constexpr Selector()
-        : MovableBase(mm::Selector) {}
+        : MovableBase(mm::Selector)
+        , plannedHomeTimer(0) {}
 
     /// Plan move of the selector to a specific filament slot
     /// @param slot index to move to
@@ -49,6 +50,10 @@ protected:
     virtual void FinishMove() override;
 
 private:
+    /// Counts main-loop iterations spent in PlannedHome while waiting for the idler to become HomingValid.
+    /// Guards against indefinite deadlock: if the idler never becomes valid, HomeFailed() fires and the
+    /// WaitForModulesErrorRecovery path surfaces the error to the user.
+    uint16_t plannedHomeTimer;
 };
 
 /// The one and only instance of Selector in the FW