Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -rfc78b1e5af6d7ab8f7656b410c4cacdfd76a49e6 -rd4f40c48a728c866c24bf44a59ff8ddd1e244ca1
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision fc78b1e5af6d7ab8f7656b410c4cacdfd76a49e6)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision d4f40c48a728c866c24bf44a59ff8ddd1e244ca1)
@@ -186,6 +186,7 @@
 
     if( heater < NUM_OF_DG_HEATERS )
     {
+#ifndef DISABLE_HEATERS_AND_TEMPS
         // Assume the target temperature has not changed
         heatersStatus[ heater ].hasTargetTempChanged = FALSE;
 
@@ -196,6 +197,7 @@
             heatersStatus[ heater ].hasTargetTempChanged = TRUE;
             result                                       = TRUE;
         }
+#endif
     }
     else
     {
@@ -241,6 +243,7 @@
 {
     BOOL status = FALSE;
 
+
     if( heater < NUM_OF_DG_HEATERS )
     {
         if ( HEATER_EXEC_STATE_OFF == heatersStatus[ heater ].state )
@@ -684,8 +687,8 @@
     }
     else
     {
-        // If not any of the above modes, just calculate the energy equation based on TRo
-        currentTemperature = getTemperatureValue( (U32)TEMPSENSORS_OUTLET_REDUNDANT );
+        // If not any of the above modes, just calculate the energy equation based on TDi
+        currentTemperature = getTemperatureValue( (U32)TEMPSENSORS_INLET_DIALYSATE );
         dutyCycle          = calculateTrimmerHeaterDutyCycle( targetTemperature, currentTemperature, targetFlowLPM, TRUE );
         state              = HEATER_EXEC_STATE_TRIMMER_CONTROL_TO_TARGET;
     }
@@ -734,10 +737,10 @@
 
         // When the trimmer heater is on, its duty cycle is adjusted at the control interval. For this control check,
         // dialysate inlet temperature sensor is used rather than the theoretical calculations.
-        F32 outletRedundantTemperature = getTemperatureValue( TEMPSENSORS_OUTLET_REDUNDANT );
-        F32 targetTemperature          = heatersStatus[ heater ].targetTempC;
-        F32 targetFlowLPM              = heatersStatus[ heater ].targetFlowLPM;
-        F32 dutyCycle                  = calculateTrimmerHeaterDutyCycle( targetTemperature, outletRedundantTemperature, targetFlowLPM, TRUE );
+        F32 dialysateInletTemperature = getTemperatureValue( (U32)TEMPSENSORS_INLET_DIALYSATE );
+        F32 targetTemperature         = heatersStatus[ heater ].targetTempC;
+        F32 targetFlowLPM             = getTargetDialysateFlowLPM();
+        F32 dutyCycle                 = calculateTrimmerHeaterDutyCycle( targetTemperature, dialysateInletTemperature, targetFlowLPM, TRUE );
 
         tempDutyCycle = heatersStatus[ heater ].dutyCycle.data + dutyCycle;
         tempDutyCycle = MIN( tempDutyCycle, HEATERS_MAX_DUTY_CYCLE );