Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -r13b6bb9e3bbd6b07d5b51d46552a9f282b4f97e4 -rf9570a9717805d0759622da836a33ee04f3fa40f
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 13b6bb9e3bbd6b07d5b51d46552a9f282b4f97e4)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision f9570a9717805d0759622da836a33ee04f3fa40f)
@@ -7,8 +7,8 @@
 *
 * @file    PresOccl.c
 *
-* @author  (last)      Dara Navaei
-* @date    (last)      13-Jul-2022
+* @author  (last)      Michael Garthwaite
+* @date    (last)      26-Aug-2022
 *
 * @author  (original)  Sean
 * @date    (original)  15-Jan-2020
@@ -22,7 +22,8 @@
 #include "NVDataMgmt.h"
 #include "OperationModes.h"
 #include "PersistentAlarm.h"
-#include "SystemCommMessages.h"
+#include "SystemCommMessages.h"
+#include "SelfTests.h"
 #include "TaskGeneral.h"
 #include "Temperatures.h"
 #include "Timers.h"
@@ -660,7 +661,7 @@
 static void checkOcclusions( void )
 {
     U32 bpOccl = getMeasuredBloodPumpOcclusion();
-    BOOL outOfRange = ( bpOccl < MIN_OCCLUSION_COUNTS || bpOccl > MAX_OCCLUSION_COUNTS ? TRUE : FALSE );
+    BOOL outOfRange = ( bpOccl < MIN_OCCLUSION_COUNTS || bpOccl > MAX_OCCLUSION_COUNTS ? TRUE : FALSE );
 
 #ifndef _RELEASE_
     if ( getSoftwareConfigStatus( SW_CONFIG_DISABLE_PRESSURE_CHECKS ) != SW_CONFIG_ENABLE_VALUE )
@@ -681,11 +682,34 @@
         // Check for BP occlusion
         if ( bpOccl > ( OCCLUSION_THRESHOLD_OFFSET + bloodPumpOcclusionAfterCartridgeInstall ) )
         {
-            signalBloodPumpHardStop();  // Stop pump immediately
-            SET_ALARM_WITH_1_U32_DATA( ALARM_ID_OCCLUSION_BLOOD_PUMP, bpOccl )
+            if ( getPreTreatmentSubState() > HD_PRE_TREATMENT_CART_INSTALL_STATE && getDrySelfTestsState() > DRY_SELF_TESTS_START_STATE )
+            {
+                // Check for occlusion
+                if ( bpOccl > ( OCCLUSION_THRESHOLD_OFFSET + bloodPumpOcclusionAfterCartridgeInstall ) )
+                {
+                    signalBloodPumpHardStop();  // Stop pump immediately
+                    SET_ALARM_WITH_1_U32_DATA( ALARM_ID_OCCLUSION_BLOOD_PUMP, bpOccl )
+                }
+            }
         }
-        else
+
+        // Check for occlusion in Treatment modes where pumps are moving
+        else if ( MODE_TREA == getCurrentOperationMode() )
         {
+            if ( TREATMENT_STOP_STATE != getTreatmentState() )
+            {
+                // Check for occlusion
+                if ( bpOccl > ( OCCLUSION_THRESHOLD_OFFSET + bloodPumpOcclusionAfterCartridgeInstall ) )
+                {
+                    signalBloodPumpHardStop();  // Stop pump immediately
+                    SET_ALARM_WITH_1_U32_DATA( ALARM_ID_OCCLUSION_BLOOD_PUMP, bpOccl )
+                }
+            }
+        }
+
+        // Clear alarm regardless of op mode once conditions are met.
+        if ( bpOccl <= ( OCCLUSION_CLEAR_THRESHOLD_OFFSET + bloodPumpOcclusionAfterCartridgeInstall ) )
+        {
             clearAlarmCondition( ALARM_ID_OCCLUSION_BLOOD_PUMP );
         }