diff --git a/src/application.cpp b/src/application.cpp
index 69d743b..6285917 100644
--- a/src/application.cpp
+++ b/src/application.cpp
@@ -128,8 +128,8 @@ void Application::PlanCommand(const modules::protocol::RequestMsg &rq) {
             break;
         }
         currentCommandRq = rq; // save the Current Command Request for indentification of responses
-        currentCommand->Reset(rq.value);
-        ReportCommandAccepted(rq, mp::ResponseMsgParamCodes::Accepted);
+        bool accepted = currentCommand->Reset(rq.value);
+        ReportCommandAccepted(rq, accepted ? mp::ResponseMsgParamCodes::Accepted : mp::ResponseMsgParamCodes::Rejected);
     } else {
         ReportCommandAccepted(rq, mp::ResponseMsgParamCodes::Rejected);
     }
diff --git a/src/logic/command_base.h b/src/logic/command_base.h
index 0d8eee5..5af61f7 100644
--- a/src/logic/command_base.h
+++ b/src/logic/command_base.h
@@ -38,7 +38,8 @@ public:
 
     /// resets the automaton
     /// @param param numerical parameter that comes with some commands (e.g. T1 for tool change 1)
-    virtual void Reset(uint8_t param) = 0;
+    /// @returns true if the command was accepted and started (which may not be possible e.g. due to filament position)
+    virtual bool Reset(uint8_t param) = 0;
 
     /// Steps the state machine. This is the preferred way of stepping the machine
     /// as it handles the global HW error states uniformly (so that the derived classes do not have to deal
diff --git a/src/logic/cut_filament.cpp b/src/logic/cut_filament.cpp
index 7326283..b45ef94 100644
--- a/src/logic/cut_filament.cpp
+++ b/src/logic/cut_filament.cpp
@@ -14,9 +14,9 @@ namespace logic {
 
 CutFilament cutFilament;
 
-void CutFilament::Reset(uint8_t param) {
+bool CutFilament::Reset(uint8_t param) {
     if (!CheckToolIndex(param)) {
-        return;
+        return false;
     }
 
     error = ErrorCode::RUNNING;
@@ -28,6 +28,7 @@ void CutFilament::Reset(uint8_t param) {
     } else {
         SelectFilamentSlot();
     }
+    return true;
 }
 
 void CutFilament::SelectFilamentSlot() {
diff --git a/src/logic/cut_filament.h b/src/logic/cut_filament.h
index ae48413..1e69575 100644
--- a/src/logic/cut_filament.h
+++ b/src/logic/cut_filament.h
@@ -15,7 +15,7 @@ public:
 
     /// Restart the automaton
     /// @param param index of filament slot to perform cut onto
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/src/logic/eject_filament.cpp b/src/logic/eject_filament.cpp
index 4eff71e..19f543f 100644
--- a/src/logic/eject_filament.cpp
+++ b/src/logic/eject_filament.cpp
@@ -15,9 +15,9 @@ namespace logic {
 
 EjectFilament ejectFilament;
 
-void EjectFilament::Reset(uint8_t param) {
+bool EjectFilament::Reset(uint8_t param) {
     if (!CheckToolIndex(param)) {
-        return;
+        return false;
     }
 
     error = ErrorCode::RUNNING;
@@ -32,6 +32,7 @@ void EjectFilament::Reset(uint8_t param) {
     } else {
         MoveSelectorAside();
     }
+    return true;
 }
 
 void EjectFilament::MoveSelectorAside() {
diff --git a/src/logic/eject_filament.h b/src/logic/eject_filament.h
index 10b68b0..998d966 100644
--- a/src/logic/eject_filament.h
+++ b/src/logic/eject_filament.h
@@ -27,7 +27,7 @@ public:
 
     /// Restart the automaton
     /// @param param index of filament slot to eject
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/src/logic/home.cpp b/src/logic/home.cpp
index 642fcfa..cded6fd 100644
--- a/src/logic/home.cpp
+++ b/src/logic/home.cpp
@@ -12,10 +12,11 @@ namespace logic {
 
 Home home;
 
-void Home::Reset(uint8_t /*param*/) {
+bool Home::Reset(uint8_t /*param*/) {
     error = ErrorCode::RUNNING;
     state = ProgressCode::Homing;
     InvalidateHomingAndFilamentState();
+    return true;
 }
 
 bool Home::StepInner() {
diff --git a/src/logic/home.h b/src/logic/home.h
index eb07d1e..560f257 100644
--- a/src/logic/home.h
+++ b/src/logic/home.h
@@ -25,7 +25,7 @@ public:
 
     /// Restart the automaton
     /// @param param unused
-    void Reset(uint8_t /*param*/) override;
+    bool Reset(uint8_t /*param*/) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/src/logic/load_filament.cpp b/src/logic/load_filament.cpp
index 658e978..0d11a40 100644
--- a/src/logic/load_filament.cpp
+++ b/src/logic/load_filament.cpp
@@ -15,14 +15,22 @@ namespace logic {
 
 LoadFilament loadFilament;
 
-void LoadFilament::Reset(uint8_t param) {
+bool LoadFilament::Reset(uint8_t param) {
     if (!CheckToolIndex(param)) {
-        return;
+        return false;
+    }
+    if (mg::globals.FilamentLoaded() > mg::FilamentLoadState::InSelector) {
+        return false; // avoid starting loadfilament if there is already some filament in the selector in some OTHER slot
+    }
+    // there is one special case though - same slot AND filament load state == InSelector (it MUST NOT be anywhere farther)
+    if (mg::globals.FilamentLoaded() > mg::FilamentLoadState::AtPulley && mg::globals.ActiveSlot() != param) {
+        return false;
     }
     dbg_logic_P(PSTR("Load Filament"));
     mg::globals.SetFilamentLoaded(param, mg::FilamentLoadState::AtPulley); // still at pulley, haven't moved yet
     verifyLoadedFilament = 1;
     Reset2(false);
+    return true;
 }
 
 void LoadFilament::ResetLimited(uint8_t param) {
diff --git a/src/logic/load_filament.h b/src/logic/load_filament.h
index 66afdd6..76c1793 100644
--- a/src/logic/load_filament.h
+++ b/src/logic/load_filament.h
@@ -16,7 +16,7 @@ public:
 
     /// Restart the automaton - performs unlimited rotation of the Pulley
     /// @param param index of filament slot to load
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// Restart the automaton for a limited rotation of the Pulley
     /// @param param index of filament slot to load
diff --git a/src/logic/move_selector.cpp b/src/logic/move_selector.cpp
index 6becc4b..a6f687d 100644
--- a/src/logic/move_selector.cpp
+++ b/src/logic/move_selector.cpp
@@ -8,14 +8,16 @@ namespace logic {
 
 MoveSelector moveSelector;
 
-void MoveSelector::Reset(uint8_t param) {
+bool MoveSelector::Reset(uint8_t param) {
     state = ProgressCode::MovingSelector;
 
     if (ms::selector.MoveToSlot(param) != ms::Selector::OperationResult::Refused) {
         // operation accepted
         error = ErrorCode::RUNNING;
+        return true;
     } else {
         error = ErrorCode::HOMING_SELECTOR_FAILED; // @@TODO
+        return false;
     }
 }
 
diff --git a/src/logic/move_selector.h b/src/logic/move_selector.h
index 8be1fab..f0a0a37 100644
--- a/src/logic/move_selector.h
+++ b/src/logic/move_selector.h
@@ -20,7 +20,7 @@ public:
 
     /// Restart the automaton
     /// @param param target selector slot
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/src/logic/no_command.h b/src/logic/no_command.h
index 2064b3a..c65ef17 100644
--- a/src/logic/no_command.h
+++ b/src/logic/no_command.h
@@ -12,7 +12,7 @@ public:
         : CommandBase() {}
 
     /// Restart the automaton
-    void Reset(uint8_t /*param*/) override {}
+    bool Reset(uint8_t /*param*/) override { return true; }
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override { return true; }
diff --git a/src/logic/set_mode.cpp b/src/logic/set_mode.cpp
index 60e7d70..abf3e8a 100644
--- a/src/logic/set_mode.cpp
+++ b/src/logic/set_mode.cpp
@@ -7,11 +7,12 @@ namespace logic {
 
 SetMode setMode;
 
-void SetMode::Reset(uint8_t param) {
+bool SetMode::Reset(uint8_t param) {
     mg::globals.SetMotorsMode(param != 0); // remember the last mode set
     // distribute the mode to all motors immediately
     mm::motion.SetMode((param == 0) ? mm::Normal : mm::Stealth);
     FinishedOK();
+    return true;
 }
 
 } // namespace logic
diff --git a/src/logic/set_mode.h b/src/logic/set_mode.h
index dc372f0..7e25a37 100644
--- a/src/logic/set_mode.h
+++ b/src/logic/set_mode.h
@@ -17,7 +17,7 @@ public:
         : CommandBase() {}
 
     /// Restart the automaton
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     /// Since we perform the TMC2130 mode change in the Reset directly, the return is always true here (command finished ok)
diff --git a/src/logic/tool_change.cpp b/src/logic/tool_change.cpp
index 7f8cb19..df21ba4 100644
--- a/src/logic/tool_change.cpp
+++ b/src/logic/tool_change.cpp
@@ -17,15 +17,15 @@ namespace logic {
 
 ToolChange toolChange;
 
-void ToolChange::Reset(uint8_t param) {
+bool ToolChange::Reset(uint8_t param) {
     if (!CheckToolIndex(param)) {
-        return;
+        return false;
     }
 
     if (param == mg::globals.ActiveSlot() && (mg::globals.FilamentLoaded() == mg::FilamentLoadState::InNozzle)) {
         // we are already at the correct slot and the filament is loaded in the nozzle - nothing to do
         dbg_logic_P(PSTR("we are already at the correct slot and the filament is loaded - nothing to do\n"));
-        return;
+        return true;
     }
 
     // we are either already at the correct slot, just the filament is not loaded - load the filament directly
@@ -43,6 +43,7 @@ void ToolChange::Reset(uint8_t param) {
         mg::globals.SetFilamentLoaded(plannedSlot, mg::FilamentLoadState::InSelector);
         feed.Reset(true, false);
     }
+    return true;
 }
 
 void logic::ToolChange::GoToFeedingToBondtech() {
diff --git a/src/logic/tool_change.h b/src/logic/tool_change.h
index 2d84071..848f499 100644
--- a/src/logic/tool_change.h
+++ b/src/logic/tool_change.h
@@ -16,7 +16,7 @@ public:
 
     /// Restart the automaton
     /// @param param index of filament slot to change to - i.e. to load
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/src/logic/unload_filament.cpp b/src/logic/unload_filament.cpp
index 2509231..122367f 100644
--- a/src/logic/unload_filament.cpp
+++ b/src/logic/unload_filament.cpp
@@ -16,12 +16,12 @@ namespace logic {
 
 UnloadFilament unloadFilament;
 
-void UnloadFilament::Reset(uint8_t /*param*/) {
+bool UnloadFilament::Reset(uint8_t /*param*/) {
 
     if (!mf::finda.Pressed() && mg::globals.FilamentLoaded() < mg::FilamentLoadState::InSelector) {
         // it looks like we have nothing in the PTFE tube, at least FINDA doesn't sense anything
         // so the filament has been probably already unloaded - terminate with OK or report an error?
-        return;
+        return true;
     }
 
     // unloads filament from extruder - filament is above Bondtech gears
@@ -30,6 +30,7 @@ void UnloadFilament::Reset(uint8_t /*param*/) {
     error = ErrorCode::RUNNING;
     unl.Reset(maxRetries);
     ml::leds.SetPairButOffOthers(mg::globals.ActiveSlot(), ml::off, ml::off);
+    return true;
 }
 
 void UnloadFilament::UnloadFinishedCorrectly() {
diff --git a/src/logic/unload_filament.h b/src/logic/unload_filament.h
index 23ba850..c22bedd 100644
--- a/src/logic/unload_filament.h
+++ b/src/logic/unload_filament.h
@@ -16,7 +16,7 @@ public:
 
     /// Restart the automaton
     /// @param param is not used, always unloads from the active slot
-    void Reset(uint8_t param) override;
+    bool Reset(uint8_t param) override;
 
     /// @returns true if the state machine finished its job, false otherwise
     bool StepInner() override;
diff --git a/tests/unit/logic/load_filament/test_load_filament.cpp b/tests/unit/logic/load_filament/test_load_filament.cpp
index b70d304..8ad1750 100644
--- a/tests/unit/logic/load_filament/test_load_filament.cpp
+++ b/tests/unit/logic/load_filament/test_load_filament.cpp
@@ -351,3 +351,41 @@ TEST_CASE("load_filament::unlimited_load_manual_stop", "[load_filament]") {
         LoadFilamentStopped(slot, lf);
     }
 }
+
+void LoadFilamentAlreadyPresentFilament(uint8_t slot, logic::LoadFilament &lf) {
+    //one of the first steps of the state machine should pick up the fact that FINDA is on and transfer into the retracting phase
+    REQUIRE(WhileTopState(lf, ProgressCode::FeedingToFinda, 5000));
+    REQUIRE(VerifyState(lf, mg::FilamentLoadState::InSelector, slot, slot, true, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::RetractingFromFinda));
+    REQUIRE(WhileCondition(lf, std::bind(SimulateRetractFromFINDA, _1, 100), 5000));
+    REQUIRE(WhileTopState(lf, ProgressCode::RetractingFromFinda, 5000));
+    REQUIRE(VerifyState(lf, mg::FilamentLoadState::AtPulley, slot, slot, false, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::FeedingToFinda));
+    // make FINDA switch on again
+    REQUIRE(WhileCondition(lf, std::bind(SimulateFeedToFINDA, _1, 100), 5000));
+    REQUIRE(WhileTopState(lf, ProgressCode::FeedingToFinda, 5000));
+    REQUIRE(VerifyState(lf, mg::FilamentLoadState::InSelector, slot, slot, true, true, ml::blink0, ml::off, ErrorCode::RUNNING, ProgressCode::RetractingFromFinda));
+    // make FINDA switch off again
+    REQUIRE(WhileCondition(lf, std::bind(SimulateRetractFromFINDA, _1, 100), 5000));
+    REQUIRE(WhileTopState(lf, ProgressCode::RetractingFromFinda, 5000));
+}
+
+TEST_CASE("load_filament::avoid_load_filament_finda", "[load_filament]") {
+    auto fls = GENERATE(mg::FilamentLoadState::InSelector, mg::FilamentLoadState::InFSensor, mg::FilamentLoadState::InNozzle);
+
+    for (uint8_t slot = 0; slot < config::toolCount; ++slot) {
+        for (uint8_t activeSlot = 0; activeSlot < config::toolCount; ++activeSlot) {
+            logic::LoadFilament lf;
+            ForceReinitAllAutomata();
+            SetFINDAStateAndDebounce(true);
+            EnsureActiveSlotIndex(activeSlot, fls);
+            REQUIRE(VerifyState(lf, fls, mi::Idler::IdleSlotIndex(), activeSlot, true, false, ml::off, ml::off, ErrorCode::OK, ProgressCode::OK));
+            bool accepted = lf.Reset(slot);
+            if (activeSlot != slot) {
+                REQUIRE_FALSE(accepted);
+            } else if (activeSlot == slot && fls <= mg::FilamentLoadState::InSelector) {
+                LoadFilamentAlreadyPresentFilament(slot, lf);
+            } else {
+                REQUIRE_FALSE(accepted);
+            }
+        }
+    }
+}