Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r6afd2e6ec147014937743fa10d0d2cf65b12e37a -rc7dcaa774c66053bcf0a52d56068d1960187bae1
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 6afd2e6ec147014937743fa10d0d2cf65b12e37a)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision c7dcaa774c66053bcf0a52d56068d1960187bae1)
@@ -52,7 +52,7 @@
 #define HEATERS_ZERO_EFFICIENCY                                    0.0F                                                            ///< Zero heater efficiency
 #define HEATER_CNTL_TRANSFER_DELTA_TEMP_C                          0.50F                                                           ///< AC heater delta temperature to transfer control from open to close loop
 #define ADJ_DELTA_TEMP_STEP                                        2.0F                                                            ///< Adjust target temperature based on D28 feedback per cycle.
-#define MAX_ADJ_DELTA_TEMP_C                                       5.0F                                                            ///< Maximum adjusted delta temperature to add/remove from calculated target temperature
+#define MAX_ADJ_DELTA_TEMP_C                                       7.0F                                                            ///< Maximum adjusted delta temperature to add/remove from calculated target temperature
 
 #define D5_HEAT_TX_INIT_FEED_FORWARD                               0.0F                                                            ///< Initial Feed forward term for heater control
 //#define D5_HEAT_TX_P_COEFFICIENT                                   0.050F                                                          ///< P Term for AC primary heater control during treatment mode.
@@ -82,7 +82,7 @@
 #define D5_HEAT_CONTROL_INTERVAL_COUNT                             ( D5_HEAT_CONTROL_INTERVAL_MS / TASK_GENERAL_INTERVAL )         ///< Primary heater control interval count.
 #define D45_HEAT_CONTROL_INTERVAL_MS                               ( 1 * MS_PER_SECOND )                                           ///< Trimmer heater control interval in milli seconds
 #define D45_HEAT_CONTROL_INTERVAL_COUNT                            ( D45_HEAT_CONTROL_INTERVAL_MS / TASK_GENERAL_INTERVAL )        ///< Trimmer heater control interval count.
-#define D5_TARGET_TEMP_ADJUST_INTERVAL_MS                          ( 5 * SEC_PER_MIN * MS_PER_SECOND / TASK_GENERAL_INTERVAL )    ///< Adjust primary target temperature
+#define D5_TARGET_TEMP_ADJUST_INTERVAL_MS                          ( 3 * SEC_PER_MIN * MS_PER_SECOND / TASK_GENERAL_INTERVAL )    ///< Adjust primary target temperature
 #define PRIMARY_HEATER_MAX_PWR_WATTS                               1400.0F                                                         ///< AC Primary Heater Max Power consumeption in Watts
 #define TX_PRIMARY_HEATER_MAX_PWR_WATTS                            700.0F                                                          ///< Estimated power to be supplied to the primary heater during treatement mode
 #define HEAT_PRIMARY_HEATER_MAX_PWR_WATTS                          980.0F                                                          ///< Estimated power to be supplied to the primary heater during heat disinfect mode
@@ -389,15 +389,23 @@
         F32 deltaTempC                  = targetTempfromTD - measuredTempAtDialyzer;
         F32 capDeltaTempC               = MIN( fabs(deltaTempC), ADJ_DELTA_TEMP_STEP );
 
+        //Assign the initial calcualted temp for adjsutment
+        if ( FALSE == isTargetTempAdjusted )
+        {
+            adjustedPrimaryTargetTemp = calcTargetTemp;
+        }
+
+        //Keep adjusting the temperature based on D28 feedback
         if ( deltaTempC > HEATERS_ZERO_DELTA_TEMP_C )
         {
-            adjustedPrimaryTargetTemp = calcTargetTemp + capDeltaTempC;
+            adjustedPrimaryTargetTemp = adjustedPrimaryTargetTemp + capDeltaTempC;
         }
         else
         {
-            adjustedPrimaryTargetTemp = calcTargetTemp - capDeltaTempC;
+            adjustedPrimaryTargetTemp = adjustedPrimaryTargetTemp - capDeltaTempC;
         }
 
+        //Make sure the adjusted temp not crossing the max and min limits.
         adjustedPrimaryTargetTemp = MIN(adjustedPrimaryTargetTemp, ( calcTargetTemp + MAX_ADJ_DELTA_TEMP_C ) );
         adjustedPrimaryTargetTemp = MAX(adjustedPrimaryTargetTemp, ( calcTargetTemp - MAX_ADJ_DELTA_TEMP_C ) );