Index: firmware/App/Controllers/BalancingChamber.c
===================================================================
diff -u -r7d7129ebe8a98694bea7cf4118f3bedf62f2157b -r9ac050d6099effbdd62070173d14dd5e225d5310
--- firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 7d7129ebe8a98694bea7cf4118f3bedf62f2157b)
+++ firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 9ac050d6099effbdd62070173d14dd5e225d5310)
@@ -60,7 +60,7 @@
 #define D48_SPEED_RANGE_LIMIT                       0.25F                                       ///< D48 speed adjustment range check limit ( D48 speed can vary +/-25% of initial calculated speed)
 #define BICARB_CHAMBER_PERIODIC_FILL_TIME           ( 1 * SEC_PER_MIN * \
                                                     ( MS_PER_SECOND / TASK_GENERAL_INTERVAL ) ) ///< Periodic bicarb chamber fill request 60 sec x 20 = 1200
-#define BAL_CHAMBER_FILL_TIMEOUT_FACTOR             1.5                                         ///< Balancing Chamber fill timeout factor (150% of observed fill count)
+#define BAL_CHAMBER_FILL_TIMEOUT_FACTOR             2.0F                                        ///< Balancing Chamber fill timeout factor (2000% of observed fill count)
 
 /// Payload record structure for balancing chamber switch only request
 typedef struct
@@ -221,7 +221,7 @@
         //Update last td dialysate flow rate
         lastTdDialysateFlowrate = tdDialysateFlowrate;
 
-        // Update fill timeout count based on the switching period (e.g. 150% of period)
+        // Update fill timeout count based on the switching period (e.g. 200% of period)
         balChamberFillTimeoutCount = (U32)( (F32)balChamberSwitchingPeriod * BAL_CHAMBER_FILL_TIMEOUT_FACTOR );
 
         //Reset the BC switching flag for new Qd.
@@ -531,7 +531,7 @@
     BAL_CHAMBER_EXEC_STATE_T state      = BAL_CHAMBER_STATE1_FILL_START;
 
     balChamberSWState                   = BAL_CHAMBER_SW_STATE1;
-    balChamberFillTimeoutCount          = 0;
+    // Preserve the Qd-based timeout so a stuck fill can fault.
     isBalChamberFillInProgress          = FALSE;
     isPressureStabilizedDuringFill      = FALSE;
     isPressureDroppedDuringFill         = FALSE;
@@ -676,12 +676,14 @@
     BOOL isBothFillsComplete        = FALSE;
     BOOL isFirstCycleNotDone        = FALSE;
     BOOL isFillCompleteOrFirstCycle = FALSE;
+    BOOL isFillTimeoutEnabled       = ( ( TRUE == isFirstCycleBCSwitchingCompleted ) &&
+                                        ( FALSE == getBalChamberSwitchingOnlyStatus() ) ) ? TRUE : FALSE;
 
     freshDialPressure               = getFilteredPressure( D18_PRES );
     spentDialPressure               = getFilteredPressure( D51_PRES );
 
-    // If fill is taking too long, set an alarm for fill timeout
-    if ( ( balChamberFillTimeoutCount > 0 ) && ( currentBalChamberFillCounter > balChamberFillTimeoutCount ) )
+    // After the first BC cycle, fault if fill never completes at the Qd-based timeout.
+    if ( ( TRUE == isFillTimeoutEnabled ) && ( balChamberFillTimeoutCount > 0 ) && ( currentBalChamberFillCounter > balChamberFillTimeoutCount ) )
     {
         SET_ALARM_WITH_2_U32_DATA( ALARM_ID_DD_BC_FILL_TIMEOUT_FAULT, currentBalChamberFillCounter, balChamberFillTimeoutCount );
 
@@ -703,15 +705,16 @@
     checkSpentFillComplete( spentDialPressure );
 
     // Check both spent and fresh side fill is complete
-    isBothFillsComplete = ( TRUE == isSpentFillComplete ) && ( TRUE == isPressureStabilizedDuringFill );
-    isFirstCycleNotDone = ( ( FALSE == isFirstCycleBCSwitchingCompleted ) && ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod ) && ( TRUE == getBalChamberSwitchingOnlyStatus() ) );
+    isBothFillsComplete = ( ( TRUE == isSpentFillComplete ) && ( TRUE == isPressureStabilizedDuringFill ) ) ? TRUE : FALSE;
+    isFirstCycleNotDone = ( FALSE == isFirstCycleBCSwitchingCompleted ) && ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod );
 
     if ( FALSE == getBalChamberSwitchingOnlyStatus() )
     {
-        isFillCompleteOrFirstCycle = isBothFillsComplete || isFirstCycleNotDone;
+        isFillCompleteOrFirstCycle = ( ( TRUE == isBothFillsComplete ) || ( TRUE == isFirstCycleNotDone ) ) ? TRUE : FALSE;
     }
 
-    if ( TRUE == isFillCompleteOrFirstCycle )
+    if ( ( TRUE == isFillCompleteOrFirstCycle ) ||
+       (  ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod ) && ( TRUE == getBalChamberSwitchingOnlyStatus() ) ) )
     {
         // close the state 1 opened valves
         valveControlForBCState1FillEnd();
@@ -842,7 +845,6 @@
     isPressureStabilizedDuringFill      = FALSE;
     isPressureDroppedDuringFill         = FALSE;
     balChamberSWState                   = BAL_CHAMBER_SW_STATE2;
-    balChamberFillTimeoutCount          = 0;
     lastPrevSpentDialPressure           = 0.0F;
     prevSpentDialPressure               = 0.0F;
     currentBalChamberSwitchingCounter   = 0;
@@ -927,6 +929,8 @@
     BOOL isBothFillsComplete        = FALSE;
     BOOL isFirstCycleNotDone        = FALSE;
     BOOL isFillCompleteOrFirstCycle = FALSE;
+    BOOL isFillTimeoutEnabled       = ( ( TRUE == isFirstCycleBCSwitchingCompleted ) &&
+                                        ( FALSE == getBalChamberSwitchingOnlyStatus() ) ) ? TRUE : FALSE;
 
     freshDialPressure               = getFilteredPressure( D18_PRES );
     spentDialPressure               = getFilteredPressure( D51_PRES );
@@ -941,8 +945,8 @@
         }
     }
 
-    // If fill is taking too long, set an alarm for fill timeout
-    if ( ( balChamberFillTimeoutCount > 0 ) && ( currentBalChamberFillCounter > balChamberFillTimeoutCount ) )
+    // After the first BC cycle, fault if fill never completes at the Qd-based timeout.
+    if ( ( TRUE == isFillTimeoutEnabled ) && ( balChamberFillTimeoutCount > 0 ) && ( currentBalChamberFillCounter > balChamberFillTimeoutCount ) )
     {
         SET_ALARM_WITH_2_U32_DATA( ALARM_ID_DD_BC_FILL_TIMEOUT_FAULT, currentBalChamberFillCounter, balChamberFillTimeoutCount );
 
@@ -954,15 +958,16 @@
     checkSpentFillComplete( spentDialPressure );
 
     // Check switching cycle time or pressure check for valve closure
-    isBothFillsComplete = ( TRUE == isSpentFillComplete ) && ( TRUE == isPressureStabilizedDuringFill );
-    isFirstCycleNotDone = ( ( FALSE == isFirstCycleBCSwitchingCompleted ) && ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod ) && ( TRUE == getBalChamberSwitchingOnlyStatus() ) );
+    isBothFillsComplete = ( ( TRUE == isSpentFillComplete ) && ( TRUE == isPressureStabilizedDuringFill ) ) ? TRUE : FALSE;
+    isFirstCycleNotDone = ( ( FALSE == isFirstCycleBCSwitchingCompleted ) && ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod ) );
 
     if ( FALSE == getBalChamberSwitchingOnlyStatus() )
     {
-        isFillCompleteOrFirstCycle = isBothFillsComplete || isFirstCycleNotDone;
+        isFillCompleteOrFirstCycle = ( ( TRUE == isBothFillsComplete ) || ( TRUE == isFirstCycleNotDone ) ) ? TRUE : FALSE;
     }
 
-    if ( TRUE == isFillCompleteOrFirstCycle )
+    if ( ( TRUE == isFillCompleteOrFirstCycle ) ||
+       (  ( currentBalChamberSwitchingCounter >= balChamberValveClosePeriod ) && ( TRUE == getBalChamberSwitchingOnlyStatus() ) ) )
     {
         // close the valves
         valveControlForBCState2FillEnd();