Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r767786753c360e9615b76a7f4a97fd0da4fcaf26 -r8dd5ee9130303e0823f5063fab0d2997c93acc90
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 767786753c360e9615b76a7f4a97fd0da4fcaf26)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 8dd5ee9130303e0823f5063fab0d2997c93acc90)
@@ -128,7 +128,8 @@
 static U32 dataPublicationTimerCounter;                                                                                            ///< Data publication timer counter.
 static U32 primaryTargetTempAdjCounter;                                                                                            ///< Primary target temperature adjustment counter.
 static BOOL isTargetTempAdjusted;                                                                                                  ///< Flag indicating that target temperature is adjusted
-static U32 adjustedPrimaryTargetTemp;                                                                                                     ///< Adjusted primary target temperature
+static U32 adjustedPrimaryTargetTemp;                                                                                              ///< Adjusted primary target temperature
+static BOOL isDialyzerTempFeedbackEnabled;                                                                                         ///< Flag indicating enable/disable the dilayser temp ( D28) based feedback adjustment
 static const F32 WATER_SPECIFIC_HEAT_DIVIDED_BY_MINUTES = 4184.0F / (F32)SEC_PER_MIN;                                              ///< Water specific heat in J/KgC / 60.
 static OVERRIDE_U32_T heatersDataPublishInterval = { HEATERS_DATA_PUBLISH_INTERVAL, HEATERS_DATA_PUBLISH_INTERVAL, 0, 0 };         ///< Heaters data publish time interval.
 static F32 convertDC;                                                                                                              ///< AC Heater converted duty cycle
@@ -199,6 +200,7 @@
     primaryTargetTempAdjCounter                      = 0;
     adjustedPrimaryTargetTemp                        = 0.0F;
     isTargetTempAdjusted                             = FALSE;
+    isDialyzerTempFeedbackEnabled                    = TRUE;
 
     for ( heater = DD_HEATERS_FIRST; heater < NUM_OF_DD_HEATERS; heater++ )
     {
@@ -337,6 +339,19 @@
 
 /*********************************************************************//**
  * @brief
+ * The setD28TempFeedbackControl function enables/disables the D28 based
+ * heater control (outer control loop ).
+ * @details \b Inputs: none
+ * @details \b Outputs: setD28TempFeedbackControl
+ * @param enable: Enables/disables the D28 based heater control.
+ *************************************************************************/
+void setD28TempFeedbackControl( BOOL enable )
+{
+    isDialyzerTempFeedbackEnabled = enable;
+}
+
+/*********************************************************************//**
+ * @brief
  * The signalHeaterControlOnQDUpdate function updates heater control based on
  * the latest treatment paratmeter (Dialysate Flow rate) change
  * @details \b Inputs: heatersStatus
@@ -729,7 +744,9 @@
             {
                 F32 deltaTempC = 0.0F;
 
-                if ( TRUE == isTargetTempAdjusted )
+                // If D28 feedback control is enabled and adjusted temp calculation is done
+                // then update the target temperature.
+                if ( (  TRUE == isTargetTempAdjusted ) && ( TRUE == isDialyzerTempFeedbackEnabled ) )
                 {
                    targetTemperature = adjustedPrimaryTargetTemp;
                 }