Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r3e02c078209aa85ad65e3e64686f53fd16e70b98 -r72ba5f3c63325b00306b544b2513c03500919d06
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 3e02c078209aa85ad65e3e64686f53fd16e70b98)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 72ba5f3c63325b00306b544b2513c03500919d06)
@@ -69,10 +69,12 @@
 #define PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C                0.015F                                                          ///< Primary heaters duty cycle per temperature in C.
 #define DATA_PUBLISH_COUNTER_START_COUNT                           70                                                              ///< Data publish counter start count.
 #define MIN_RO_HEATER_FLOWRATE_LPM                                 0.2F                                                            ///< Minimum target RO heater flow rate in L/min.
+#define PRIMARY_HEATER_POWER_TOL                                   0.1F                                                            ///< Primary heater power tolerance.
 
 static const F32 WATER_SPECIFIC_HEAT_DIVIDED_BY_MINUTES = 4184 / SEC_PER_MIN;                                                      ///< Water specific heat in J/KgC / 60.
 static const F32 PRIMARY_HEATERS_MAXIMUM_POWER_WATTS    = 475 + 237.5F;                                                            ///< Primary heaters maximum power (main primary = 475W and small primary = 237.5W).
 static const F32 HEATERS_VOLTAGE_TOLERANCE_V            = HEATERS_MAX_OPERATING_VOLTAGE_V * HEATERS_MAX_VOLTAGE_OUT_OF_RANGE_TOL;  ///< Heaters voltage tolerance in volts.
+static const F32 PRIMARY_HEATER_VOLTAGE_TOLERANCE_V     = HEATERS_MAX_OPERATING_VOLTAGE_V * PRIMARY_HEATER_POWER_TOL;              ///< Primary heater power voltage tolerance in volts.
 
 /// Heaters data structure
 typedef struct
@@ -147,6 +149,7 @@
     initPersistentAlarm( ALARM_ID_DG_MAIN_PRIMARY_HEATER_VOLTAGE_OUT_OF_RANGE, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_DG_SMALL_PRIMARY_HEATER_VOLTAGE_OUT_OF_RANGE, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_DG_TRIMMER_HEATER_VOLTAGE_OUT_OF_RANGE, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS );
+    initPersistentAlarm( ALARM_ID_DG_PRIMARY_HEATER_POWER_VOLTAGE_OUT_OF_RANGE, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS, HEATERS_VOLTAGE_OUT_OF_RANGE_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_RO_FLOW_TOO_LOW_WHILE_PRIMARY_HEATER_IS_ON, HEATERS_ON_NO_FLOW_TIMEOUT_MS, HEATERS_ON_NO_FLOW_TIMEOUT_MS );
     initPersistentAlarm( ALARM_ID_DIALYSATE_FLOW_TOO_LOW_WHILE_TRIMMER_HEATER_IS_ON, HEATERS_ON_NO_FLOW_TIMEOUT_MS, HEATERS_ON_NO_FLOW_TIMEOUT_MS );
 }
@@ -592,7 +595,6 @@
     heatersStatus[ heater ].calculatedTemperature = currentTemperature;
     heatersStatus[ heater ].inactiveRsrvr         = getInactiveReservoir();
     heatersStatus[ heater ].targetFlow            = targetFlowLPM;
-    heatersStatus[ heater ].dutyCycle             = 0.0F;
     trimmerHeaterControlCounter                   = 0;
 
     // Cap the minimum duty cycle. So if it is calculated to negative, set it to 0
@@ -856,8 +858,7 @@
  *************************************************************************/
 static void monitorHeatersVoltage( void )
 {
-    F32 powerMainPriVoltage = getMonitoredLineLevel( MONITORED_LINE_24V_POWER_PRIM_HTR_V );
-    F32 mainPriVoltage      = getMonitoredLineLevel( MONITORED_LINE_24V_GND_MAIN_PRIM_HTR_V );
+    F32 mainPriVoltage = getMonitoredLineLevel( MONITORED_LINE_24V_GND_MAIN_PRIM_HTR_V );
 
 #ifndef _RELEASE_
     if ( SW_CONFIG_ENABLE_VALUE == getSoftwareConfigStatus( SW_CONFIG_ENABLE_V3_SYSTEM ) )
@@ -888,6 +889,17 @@
         checkPersistentAlarm( ALARM_ID_DG_MAIN_PRIMARY_HEATER_VOLTAGE_OUT_OF_RANGE,  isMainPriOut,  mainPriDC,  HEATERS_VOLTAGE_TOLERANCE_V );
         checkPersistentAlarm( ALARM_ID_DG_SMALL_PRIMARY_HEATER_VOLTAGE_OUT_OF_RANGE, isSmallPriOut, smallPriDC, HEATERS_VOLTAGE_TOLERANCE_V );
         checkPersistentAlarm( ALARM_ID_DG_TRIMMER_HEATER_VOLTAGE_OUT_OF_RANGE,       isTrimmerOut,  trimmerDC,  HEATERS_VOLTAGE_TOLERANCE_V );
+
+#ifndef _RELEASE_
+        if ( SW_CONFIG_ENABLE_VALUE != getSoftwareConfigStatus( SW_CONFIG_ENABLE_V3_SYSTEM ) )
+#endif
+        {
+            // If the system is DVT, check the primary heater's power line voltage
+            F32 powerMainPriVoltage = getMonitoredLineLevel( MONITORED_LINE_24V_POWER_PRIM_HTR_V );
+            BOOL isPriPowerOut      = ( fabs( powerMainPriVoltage - HEATERS_MAX_OPERATING_VOLTAGE_V ) > PRIMARY_HEATER_VOLTAGE_TOLERANCE_V ? TRUE : FALSE );
+
+            checkPersistentAlarm( ALARM_ID_DG_PRIMARY_HEATER_POWER_VOLTAGE_OUT_OF_RANGE, isPriPowerOut, powerMainPriVoltage, PRIMARY_HEATER_VOLTAGE_TOLERANCE_V );
+        }
     }
 }