Index: firmware/App/Services/Reservoirs.c
===================================================================
diff -u -r867eed1d3a71f8fac87ac6dece093a391663188a -r5addd92e279ebc0871364fee70e3ac74db21001a
--- firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision 867eed1d3a71f8fac87ac6dece093a391663188a)
+++ firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision 5addd92e279ebc0871364fee70e3ac74db21001a)
@@ -67,6 +67,8 @@
 static U32 reservoirSwitchStartTimeMS = 0;                                                               ///< Reservoir switch start time in milliseconds.
 static S32 timeWaitToFillMS = 0;                                                                         ///< Time to wait to fill in milliseconds.
 static F32 targetFillFlowLPM = 0.0;                                                                      ///< Target fill flow in liters/minutes.
+static U32 previousDialysateFlowMLP = 0;                                                                 ///< Previous dialysate flow rate in mL/min.
+static F32 previousUFFlowMLP = 0.0;                                                                      ///< Previous ultrafiltration flow rate in mL/min.
 
 // ********** private function prototypes **********
 
@@ -75,6 +77,7 @@
 static void checkReservoirMaxVolume( void );
 static F32  getTargetFillFlowRateLPM( void );
 static U32  getFillTimeMS( void );
+static void calculateActiveReservoirCycleTime( void );
 static void publishReservoirData( void );
 
 static TREATMENT_RESERVOIR_MGMT_STATE_T handleReservoirMgmtStartState( void );
@@ -92,7 +95,8 @@
  * @details Outputs: reservoirsState, timeStartMS, timeDepletionMS, volTotalMl,
  * volSpentMl, reservoirsPublicationCounter, dilutionLevelPct, dgOpMode, dgSubMode,
  * timeReservoirInUseMS, volSpentUFML, activeReservoir, recirculationLevelPct,
- * reservoirSwitchStartTimeMS, timeWaitToFillMS, targetFillFlowLPM
+ * reservoirSwitchStartTimeMS, timeWaitToFillMS, targetFillFlowLPM,
+ * previousDialysateFlowRate
  * @return none
  *************************************************************************/
 void initReservoirs( void )
@@ -113,6 +117,7 @@
     reservoirSwitchStartTimeMS  = 0;
     timeWaitToFillMS            = 0;
     targetFillFlowLPM           = 0.0;
+    previousDialysateFlowMLP    = 0;
 }
 
 /*********************************************************************//**
@@ -148,6 +153,7 @@
 
     checkReservoirDepletionTime();
     checkReservoirMaxVolume();
+    calculateActiveReservoirCycleTime();
 
     // TODO do we need this? Should we not call the reservoir management exec function in saline bolus?
 
@@ -195,15 +201,16 @@
 
 /*********************************************************************//**
  * @brief
- * The getReservoirCycleTime function returns the depletion time which is the
- * cycle time in milliseconds.
+ * The setHeatersTemperatureAndTime function is an API to call other internal
+ * functions to set the trimmer's heater target temperature and times that are
+ * required to calculated the heaters target temperature in DG.
  * @details Inputs: none
- * @details Outputs: timeDepleteMS
- * @return timeDepleteMS which is the reservoir cycle time
+ * @details Outputs: none
+ * @return none
  *************************************************************************/
-U32 getReservoirCycleTime( void )
+void setHeatersTemperatureAndTime( void )
 {
-    return timeDepleteMS;
+    calculateActiveReservoirCycleTime();
 }
 
 // ********** private functions **********
@@ -303,6 +310,51 @@
 
 /*********************************************************************//**
  * @brief
+ * The calculateActiveReservoirCycleTime function calculates the active reservoir
+ * cycle time in milliseconds. If the target dialysate flow or target ultrafilter
+ * flow has changed the function sends the new active reservoir cycle time
+ * to the DG.
+ * @details Inputs: previousDialysateFlowMLP, previousUFFlowMLP
+ * @details Outputs: previousDialysateFlowMLP, previousUFFlowMLP
+ * @return none
+ *************************************************************************/
+static void calculateActiveReservoirCycleTime( void )
+{
+    U32 dialysateFlowMLP     = getTreatmentParameterU32( TREATMENT_PARAM_DIALYSATE_FLOW );
+    F32 fillTimeMS           = ( (F32)FILL_RESERVOIR_TO_VOLUME_ML / ( getTargetFillFlowRateLPM() * ML_PER_LITER ) ) * SEC_PER_MIN * MS_PER_SECOND;
+    F32 targetUFFlowMLP      = getCurrentUFSetRate();
+    F32 timeReservoirCycleMS = fillTimeMS;
+
+    // Check if target UF flow is not zero to consider it in the calculations too
+    if ( targetUFFlowMLP > NEARLY_ZERO )
+    {
+        // If UF is not 0, the active reservoir cycle time is minimum of UF depletion and fill time
+        F32 timeUFDepletionMS = ( (F32)FILL_RESERVOIR_TO_VOLUME_ML / targetUFFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
+        timeReservoirCycleMS  = MIN( fillTimeMS, timeUFDepletionMS );
+    }
+
+    // If the target dialysate flow rate has changed, it means the cycle time (depletion time) has changed
+    // So the new value has to be sent again.
+    if ( ( previousDialysateFlowMLP != dialysateFlowMLP ) || ( previousUFFlowMLP != targetUFFlowMLP ) )
+    {
+        DG_CMD_DIALYSATE_HEATING_PARAMS_T params;
+        params.trimmerTargetTemperature   = getTreatmentParameterF32( TREATMENT_PARAM_DIALYSATE_TEMPERATURE );
+        params.timeReservoirWait2SwitchMS = RESERVOIR_SETTLE_TIME_MS + RESERVOIR_CYCLE_EXTRA_MARGIN_TIME_MS;
+        params.timeReservoirFillMS        = fillTimeMS;
+        params.timeReservoirCycleMS       = timeReservoirCycleMS;
+        params.dialysateFlowLPM           = dialysateFlowMLP / ML_PER_LITER;
+
+        cmdSetDGDialysateHeatingParams( params );
+
+        // Update the previous dialysate flow and UF flow regardless of which one changed
+        // If anything of have not changed, then the update does not change anything
+        previousDialysateFlowMLP = dialysateFlowMLP;
+        previousUFFlowMLP        = targetUFFlowMLP;
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The publishReservoirData function publishes reservoirs data during treatment.
  * @details Inputs: reservoirsPublicationCounter
  * @details Outputs: reservoirsPublicationCounter
@@ -411,8 +463,9 @@
         // Using the fresh remaining volume, time to spent the fresh remaining is calculated by dividing the volume to
         // target dialysate flow rate. The target dialysate flow rate is used to be able to respond to the flow changes
         // by the user
+        U32 targetDialysateFlowMLP = getTreatmentParameterU32( TREATMENT_PARAM_DIALYSATE_FLOW );
         F32 volFreshML             = FILL_RESERVOIR_TO_VOLUME_ML - volSpentML;
-        F32 timeFreshRemainingMS   = ( volFreshML / (F32)getTreatmentParameterU32( TREATMENT_PARAM_DIALYSATE_FLOW ) ) * SEC_PER_MIN * MS_PER_SECOND;
+        F32 timeFreshRemainingMS   = ( volFreshML / (F32)targetDialysateFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
         F32 volMaxUFML             = FILL_RESERVOIR_TO_VOLUME_ML * MAX_RESERVOIR_DILUTION;
         F32 ultrafiltrationFlowMLP = getCurrentUFSetRate();