Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -rd7926685f2fe3086bab183166119f0965a192a69 -r34ed52c598042fdcfa5526e3b1d46fa09b040199
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision d7926685f2fe3086bab183166119f0965a192a69)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 34ed52c598042fdcfa5526e3b1d46fa09b040199)
@@ -344,6 +344,7 @@
  *************************************************************************/
 void execHeatersMonitor( void )
 {
+    // TODO check for the heaters' fault flags and fault if any of them are at fault it should alarm
 #ifndef IGNORE_HEATERS_MONITOR
     F32 primaryHeatersInternalTemp = getTemperatureValue( TEMPSENSORS_PRIMARY_HEATER_INTERNAL );
     F32 trimmerHeaterInternalTemp  = getTemperatureValue( TEMPSENSORS_TRIMMER_HEATER_INTERNAL );
@@ -390,23 +391,29 @@
 #endif
 
     /*
-     * If any of the heaters are on, check if the flow is below than the minimum value
+     * If any of the heaters are on or any of the heaters' PWMs are not zero, check if the flow is below than the minimum value
      * If the flow is below minimum for the first time, set the variables
      * If the flow is below minimum for more than the defined time, stop the heaters and raise the alarm
      * If the flow is in range, reset the variables
+     * This is to make sure that any of the heaters do not stay on while there is no flow
      */
-    if ( ( TRUE == isPrimaryHeaterOn ) || ( TRUE == isTrimmerHeaterOn ) )
+    BOOL isHeaterOn   = ( TRUE == isPrimaryHeaterOn ) || ( TRUE == isTrimmerHeaterOn );
+    BOOL isPWMNonZero = ( mainPrimaryHeaterDutyCycle > HEATERS_MIN_DUTY_CYCLE ) || ( smallPrimaryHeaterDutyCycle > HEATERS_MIN_DUTY_CYCLE ) ||
+                        ( trimmerHeaterDutyCycle > HEATERS_MIN_DUTY_CYCLE );
+
+    if ( ( TRUE == isHeaterOn ) || ( TRUE == isPWMNonZero ) )
     {
-        //TODO add a check for the pwm to not be 0
         F32 measuredFlow = getMeasuredROFlowRate();
 
         if ( measuredFlow < MIN_RO_FLOWRATE_LPM )
         {
+            // Flow is below minimum for the first time
             if ( FALSE == isFlowBelowMin )
             {
                 isFlowBelowMin           = TRUE;
                 heatersOnWithNoFlowTimer = getMSTimerCount();
             }
+            // Flow is below minimum for a long time so raise the alarm
             else if ( TRUE == didTimeout( heatersOnWithNoFlowTimer, HEATERS_ON_NO_FLOW_TIMEOUT_MS ) )
             {
                 stopPrimaryHeater();
@@ -835,12 +842,12 @@
  *************************************************************************/
 static void resetHeaterState( NAME_OF_HEATER_T heater )
 {
-    if ( heater == PRIMARY_HEATER )
+    if ( PRIMARY_HEATER == heater )
     {
         mainPrimaryHeaterDutyCycle = MAIN_PRIMARY_HEATER_MAX_DUTY_CYCLE;
         resetPIController( PI_CONTROLLER_ID_PRIMARY_HEATER, MAIN_PRIMARY_HEATER_MAX_DUTY_CYCLE );
     }
-    else if ( heater == TRIMMER_HEATER )
+    else if ( TRIMMER_HEATER == heater )
     {
         trimmerHeaterDutyCycle = TRIMMER_HEATER_MAX_DUTY_CYCLE;
         resetPIController( PI_CONTROLLER_ID_TRIMMER_HEATER, TRIMMER_HEATER_MAX_DUTY_CYCLE );