Index: firmware/App/Controllers/BalancingChamber.c
===================================================================
diff -u -r9ff57b5ab7490ee5bbc2c51b25f738ee6c569ec1 -r4a80b214d221c1f64feb215d828a10d8fddbaf4d
--- firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 9ff57b5ab7490ee5bbc2c51b25f738ee6c569ec1)
+++ firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 4a80b214d221c1f64feb215d828a10d8fddbaf4d)
@@ -20,6 +20,7 @@
 #include "ConcentratePumps.h"
 #include "DialysatePumps.h"
 #include "FpgaDD.h"
+#include "Heaters.h"
 #include "ModeStandby.h"
 #include "Messaging.h"
 #include "OperationModes.h"
@@ -63,6 +64,7 @@
 static BOOL balanceChamberSwitchingOnly;                                                        ///< Balancing chamber switching without any pressure check and dosing delivery.
 static OVERRIDE_F32_T acidDoseVolume;                                                           ///< Acid concentrate volume in ml ( overrideable).
 static OVERRIDE_F32_T bicarbDoseVolume;                                                         ///< Bicarb concentrate volume in ml ( overrideable).
+static F32 lastTdDialysateFlowrate;                                                             ///< Previous TD dialysate flow rate
 
 // ********** private function prototypes **********
 
@@ -107,6 +109,7 @@
     isBalChamberFillInProgress                  = FALSE;
     currentBalChamberSwitchingCounter           = 0;
     isPressureStalbilizedDuringFill             = FALSE;
+    lastTdDialysateFlowrate                     = 0.0F;
     balChamberDataPublicationTimerCounter       = 0;
 }
 
@@ -134,18 +137,29 @@
  *************************************************************************/
 void updateBalChamberSwitchingPeriod( void )
 {
-    // update the balancing chamber switching frequency
-    balChamberSwitchingFreq.data = getTDDialysateFlowrate() / BAL_CHAMBER_FILL_VOLUME_ML;
+    F32 tdDialysateFlowrate = getTDDialysateFlowrate();
 
-    //update the switching period in task interval for balancing chamber fill timeout check
-    balChamberSwitchingPeriod = (U32)( (F32)SEC_PER_MIN / getBalChamberSwitchingFreq() * ( MS_PER_SECOND / TASK_GENERAL_INTERVAL ) );
+    if ( lastTdDialysateFlowrate != tdDialysateFlowrate )
+    {
+        // update the balancing chamber switching frequency
+        balChamberSwitchingFreq.data = tdDialysateFlowrate / BAL_CHAMBER_FILL_VOLUME_ML;
 
-    // finish the balancing chamber fill 50 ms prior completing the regular cycle time.
-    balChamberSwitchingPeriod -= 1;
+        //update the switching period in task interval for balancing chamber fill timeout check
+        balChamberSwitchingPeriod = (U32)( (F32)SEC_PER_MIN / getBalChamberSwitchingFreq() * ( MS_PER_SECOND / TASK_GENERAL_INTERVAL ) );
 
-    //Testing
-    balChamberValveClosePeriod = balChamberSwitchingPeriod;
-    balChamberValveClosePeriod -= 1;   // Close valves prior 50 msecond for testing
+        // finish the balancing chamber fill 50 ms prior completing the regular cycle time.
+        balChamberSwitchingPeriod -= 1;
+
+        //Update last td dialysate flow rate
+        lastTdDialysateFlowrate = tdDialysateFlowrate;
+
+        //Update heater control on dialysate flow change
+        signalHeaterControlOnQDUpdate( D5_HEAT );
+
+        //Testing
+        balChamberValveClosePeriod = balChamberSwitchingPeriod;
+        balChamberValveClosePeriod -= 1;   // Close valves prior 50 msecond for testing
+    }
 }
 
 /*********************************************************************//**