Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r51c295e1dc413d3774dae303e7f98b2f4c86bae4 -r6afd2e6ec147014937743fa10d0d2cf65b12e37a
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 51c295e1dc413d3774dae303e7f98b2f4c86bae4)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 6afd2e6ec147014937743fa10d0d2cf65b12e37a)
@@ -51,7 +51,8 @@
 #define HEATERS_DUTY_CYCLE_CONVERSION_FACTOR                       100.0F                                                          ///< Heaters duty cycle 0: OFF, 100: 100% duty cycle.
 #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 MAX_ADJ_DELTA_TEMP_C                                       3.0F                                                            ///< Maximum adjusted delta temperature to add/remove from calculated target temperature
+#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 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.
@@ -81,7 +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                          ( 10 * SEC_PER_MIN * MS_PER_SECOND / TASK_GENERAL_INTERVAL )    ///< Adjust primary target temperature
+#define D5_TARGET_TEMP_ADJUST_INTERVAL_MS                          ( 5 * 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
@@ -386,7 +387,7 @@
         F32 measuredTempAtDialyzer      = getConductivityTemperatureValue( D27_COND );
         F32 calcTargetTemp              = getHeaterTargetTemperature( D5_HEAT );
         F32 deltaTempC                  = targetTempfromTD - measuredTempAtDialyzer;
-        F32 capDeltaTempC               = MIN( fabs(deltaTempC), MAX_ADJ_DELTA_TEMP_C );
+        F32 capDeltaTempC               = MIN( fabs(deltaTempC), ADJ_DELTA_TEMP_STEP );
 
         if ( deltaTempC > HEATERS_ZERO_DELTA_TEMP_C )
         {