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 );
Index: firmware/App/Services/Reservoirs.c
===================================================================
diff -u -ra0c1350fb3266a722f91298dde1e97876081cd2e -r1ac16991f665ddf377a4fd17f91c1949b64edf8e
--- firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision a0c1350fb3266a722f91298dde1e97876081cd2e)
+++ firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision 1ac16991f665ddf377a4fd17f91c1949b64edf8e)
@@ -55,6 +55,9 @@
 #define DATA_PUBLISH_COUNTER_START_COUNT          5                                               ///< Data publish counter start count.
 #define NUM_OF_ACID_AND_BICARB_NV_DATA_TO_CHECK   1                                               ///< Number of acid and bicarb non-volatile data to check.
 
+#define TRIMMER_HEATER_TARGET_TEMP_GAIN           0.002F                                          ///< Trimmer heater target temperature gain.
+#define TRIMMER_HEATER_TARGET_TEMP_OFFSET         0.3F                                            ///< Trimmer heater target temperature offset.
+
 // ********** private data **********
 
 /// Heaters temperature calculation data structure
@@ -565,7 +568,7 @@
  *************************************************************************/
 F32  getTrimmerHeaterTargetTemperature( void )
 {
-    return heatersTempCalc.tempTargetTrimmer;
+    return heatersTempCalc.tempTargetTrimmer + ( getTargetDialysateFlowLPM() * TRIMMER_HEATER_TARGET_TEMP_GAIN ) + TRIMMER_HEATER_TARGET_TEMP_OFFSET;
 }
 
 /*********************************************************************//**
@@ -642,7 +645,7 @@
     heatersTempCalc.timeReservoirCycleMS       = params.timeReservoirCycleMS;
     heatersTempCalc.timeReservoirFill2SwitchMS = params.timeReservoirWait2SwitchMS;
     heatersTempCalc.timeReservoirFillMS        = params.timeReservoirFillMS;
-    heatersTempCalc.tempTargetTrimmer          = params.trimmerTargetTemperature;
+    heatersTempCalc.tempTargetTrimmer          = getTrimmerHeaterTargetTemperature();
     heatersTempCalc.flowTargetDialysateLPM     = params.dialysateFlowLPM;
     heatersTempCalc.usePriTargetTempEquation   = params.usePriTargetTempEquation;
 
@@ -664,7 +667,7 @@
  *************************************************************************/
 F32 getPrimaryHeaterTargetTemperature( void )
 {
-    F32 tempTargetC      = heatersTempCalc.tempTargetTrimmer;
+    F32 tempTargetC      = getTrimmerHeaterTargetTemperature();
     F32 priTargetTempC   = 0.0F;
     F32 targetFillVolML  = getTargetFillVolumeML();
     F32 UFTimeConstant   = 0.0F;
@@ -695,7 +698,7 @@
              * 8. T_primary_target = T_mix_target * (Q_total / Q_RO) - (Q_acid / Q_RO) * T_acid - (Q_bicarb / Q_RO) * T_bicarb
              */
 
-            tempReservoirUse                     = heatersTempCalc.tempTargetTrimmer;
+            tempReservoirUse                     = getTrimmerHeaterTargetTemperature();
             heatersTempCalc.tempReservoirEndFill = tempReservoirUse - ( heatersTempCalc.timeReservoirFill2SwitchMS * RsrvrTauCPerMS );
             heatersTempCalc.tempReservoir0       = heatersTempCalc.tempReservoirEndFill - ( ( heatersTempCalc.timeReservoirFillMS * HALF ) * RsrvrTauCPerMS );
 
@@ -709,7 +712,7 @@
         }
         else
         {
-            tempTargetC                          = heatersTempCalc.tempTargetTrimmer + RESERVOIR_EXTRA_TEMPERATURE;
+            tempTargetC                          = getTrimmerHeaterTargetTemperature() + RESERVOIR_EXTRA_TEMPERATURE;
         }
     }