Index: firmware/App/Controllers/DGInterface.c
===================================================================
diff -u -r19f13e67288117e7f81c1245a75cc6b5f8aaf899 -r8036381b5c41ab87146c929eeeb9ba073efd4541
--- firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 19f13e67288117e7f81c1245a75cc6b5f8aaf899)
+++ firmware/App/Controllers/DGInterface.c	(.../DGInterface.c)	(revision 8036381b5c41ab87146c929eeeb9ba073efd4541)
@@ -50,7 +50,9 @@
 #define DIALYSATE_TEMP_LOW_SAFETY_LIMIT_C        42.0F                      ///< Dialysate low safety temperature limit in C.
 #define DIALYSATE_TEMP_LOW_SAFETY_TIMEOUT_MS     ( 10 * MS_PER_SECOND )     ///< Dialysate temperature low safety timeout in milliseconds.
 #define DG_DATA_FRESHNESS_TIMEOUT_MS             ( 3 * MS_PER_SECOND )      ///< DG data freshness timeout (in ms).
+#define DG_TRIMMER_HTR_CHECK_INTERVAL            ( MS_PER_SECOND / TASK_GENERAL_INTERVAL + 2 )   ///< DG trimmer heater check interval in general task execution time counts.
 
+
 // ********** private data **********
 
 // DG status
@@ -66,6 +68,8 @@
 static F32 dgHeatDisinfectTemp;                                             ///< Heat disinfect temperature reported by the DG.
 static F32 dgTrimmerTempSet;                                                ///< Trimmer heater target temperature commanded.
 
+static U32 dgTrimmerTempCheckTimerCtr;                                      ///< Trimmer heater temp check interval timer counter.
+
 /// Measured weight from load cells.
 static OVERRIDE_F32_T loadCellWeightInGrams[ NUM_OF_LOAD_CELLS ];
 
@@ -124,7 +128,8 @@
 
     dgStarted                       = FALSE;
     dgTrimmerHeaterOn               = FALSE;
-    dgTrimmerTempSet                = 0.0F;
+    dgTrimmerTempSet                = 0.0F;
+    dgTrimmerTempCheckTimerCtr      = 0;
     dgActiveReservoirSet            = DG_RESERVOIR_2;
     dgActiveReservoir               = DG_RESERVOIR_2;
     dgReservoirFillVolumeTargetSet  = 0;
@@ -244,7 +249,11 @@
         checkDGRestart();
 
         // Check the status of the trimmer heater
-        checkDGTrimmerHeaterStatus();
+        if ( ++dgTrimmerTempCheckTimerCtr >= DG_TRIMMER_HTR_CHECK_INTERVAL )
+        {
+            dgTrimmerTempCheckTimerCtr = 0;
+            checkDGTrimmerHeaterStatus();
+        }
     }
 }
 
@@ -474,6 +483,19 @@
 
 /*********************************************************************//**
  * @brief
+ * The getTrimmerHeaterCommandedOn function gets the latest on/off commanded
+ * status of the trimmer heater.
+ * @details Inputs: dgTrimmerHeaterOn
+ * @details Outputs: none
+ * @return dgTrimmerHeaterOn
+ *************************************************************************/
+BOOL getTrimmerHeaterCommandedOn( void )
+{
+    return dgTrimmerHeaterOn;
+}
+
+/*********************************************************************//**
+ * @brief
  * The getDGDisinfectsStates function returns the DG disinfects readings.
  * @details Inputs: none
  * @details Outputs: none
Index: firmware/App/Controllers/DGInterface.h
===================================================================
diff -u -r19f13e67288117e7f81c1245a75cc6b5f8aaf899 -r8036381b5c41ab87146c929eeeb9ba073efd4541
--- firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision 19f13e67288117e7f81c1245a75cc6b5f8aaf899)
+++ firmware/App/Controllers/DGInterface.h	(.../DGInterface.h)	(revision 8036381b5c41ab87146c929eeeb9ba073efd4541)
@@ -119,6 +119,7 @@
 F32 getReservoirBackupWeightLargeFilter( DG_RESERVOIR_ID_T resID );
 F32 getDialysateTemperature( void );
 F32 getHeatDisinfectTemperatureSensorValue( void );
+BOOL getTrimmerHeaterCommandedOn( void );
 DG_DISINFECT_UI_STATES_T getDGDisinfectsStates( void );
 DG_MIXING_RATIOS_T getDGMixingRatios( void );
 void getHDVersionDGServiceAndUsageData( DG_SERVICE_AND_USAGE_DATA_T* data );
Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r9d924ec76ce770eb2a94088bfe37bfb0e30981a8 -r8036381b5c41ab87146c929eeeb9ba073efd4541
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 9d924ec76ce770eb2a94088bfe37bfb0e30981a8)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 8036381b5c41ab87146c929eeeb9ba073efd4541)
@@ -937,13 +937,15 @@
     if ( TRUE == doesAlarmStatusIndicateStop() )
     {
         signalDialInPumpHardStop();
-        cmdStopDGTrimmerHeater();
+        if ( TRUE == getTrimmerHeaterCommandedOn() )
+        {
+            cmdStopDGTrimmerHeater();
+        }
     }
     else if ( TRUE == alarmActionResumeReceived )
     {
         alarmActionResumeReceived = FALSE;
-        //setDialInPumpTargetFlowRate( DIP_PATIENT_CONNECTION_FLOW_RATE_ML_MIN, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
-        setDialInPumpTargetFlowRate( 250, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP ); // TODO remove this line once the new flow control is implemented
+        setDialInPumpTargetFlowRate( DIP_PATIENT_CONNECTION_FLOW_RATE_ML_MIN, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
         cmdStartDGTrimmerHeater();
     }