Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r7e1358a440116fedad5a049d49c2d6f9be85d60e -r1ac16991f665ddf377a4fd17f91c1949b64edf8e
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 7e1358a440116fedad5a049d49c2d6f9be85d60e)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 1ac16991f665ddf377a4fd17f91c1949b64edf8e)
@@ -684,8 +684,8 @@
     }
     else
     {
-        // If not any of the above modes, just calculate the energy equation based on TDi
-        currentTemperature = getTemperatureValue( (U32)TEMPSENSORS_INLET_DIALYSATE );
+        // If not any of the above modes, just calculate the energy equation based on TRo
+        currentTemperature = getTemperatureValue( (U32)TEMPSENSORS_OUTLET_REDUNDANT );
         dutyCycle          = calculateTrimmerHeaterDutyCycle( targetTemperature, currentTemperature, targetFlowLPM, TRUE );
         state              = HEATER_EXEC_STATE_TRIMMER_CONTROL_TO_TARGET;
     }
@@ -734,7 +734,7 @@
 
         // 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 dialysateInletTemperature = getTemperatureValue( (U32)TEMPSENSORS_INLET_DIALYSATE );
+        F32 dialysateInletTemperature = getTemperatureValue( (U32)TEMPSENSORS_OUTLET_REDUNDANT );
         F32 targetTemperature         = heatersStatus[ heater ].targetTempC;
         F32 targetFlowLPM             = getTargetDialysateFlowLPM();
         F32 dutyCycle                 = calculateTrimmerHeaterDutyCycle( targetTemperature, dialysateInletTemperature, targetFlowLPM, TRUE );