Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -rb8f298547eb578000b3ff3cf55732fda7a689ce0 -r1440a4a2be8d12edebd405a20807882e5d32d619
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision b8f298547eb578000b3ff3cf55732fda7a689ce0)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 1440a4a2be8d12edebd405a20807882e5d32d619)
@@ -515,11 +515,13 @@
     }
     else if ( ( DG_MODE_HEAT == opMode ) || ( DG_MODE_CHEM == opMode ) )
     {
-        // If the mode is any of the disinfects, especially heat, use the target flow rate instead of the avg. flow
-        // Most of the times the heater should be running at 100% duty cycle since the target temperature is 81 C
-        targetFlow = getTargetROPumpFlowRateLPM();
-        dutyCycle  = calculatePrimaryHeaterDutyCycle( targetTemperature, inletTemperature, targetFlow, FALSE );
-        state      = HEATER_EXEC_STATE_CONTROL_TO_DISINFECT_TARGET;
+        // If the mode is any of the disinfects, specially heat, use the target flow rate instead of the avg. flow
+        // Most of the times the heater should be running at 100% duty cycle since the target temperature is far from
+        // the inlet temperature
+        targetFlow       = getTargetROPumpFlowRateLPM();
+        inletTemperature = getTemperatureValue( (U32)TEMPSENSORS_OUTLET_PRIMARY_HEATER );
+        dutyCycle        = calculatePrimaryHeaterDutyCycle( targetTemperature, inletTemperature, targetFlow, FALSE );
+        state            = HEATER_EXEC_STATE_CONTROL_TO_DISINFECT_TARGET;
     }
     else
     {
@@ -585,7 +587,7 @@
 static HEATERS_STATE_T handleHeaterStateControlToDisinfectTarget( DG_HEATERS_T heater )
 {
     HEATERS_STATE_T state  = HEATER_EXEC_STATE_CONTROL_TO_DISINFECT_TARGET;
-    F32 currentTemperature = getTemperatureValue( TEMPSENSORS_HEAT_DISINFECT );
+    F32 currentTemperature = getTemperatureValue( TEMPSENSORS_OUTLET_PRIMARY_HEATER );
     F32 targetTemperature  = heatersStatus[ DG_PRIMARY_HEATER ].targetTemp;
 
     if ( currentTemperature < targetTemperature )