Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -r34d0843fa73e79ba3b085dd4aaa393a1ec126fd4 -ref398e685d6cfbdcb8c18fd9319819672c6c9d89
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 34d0843fa73e79ba3b085dd4aaa393a1ec126fd4)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision ef398e685d6cfbdcb8c18fd9319819672c6c9d89)
@@ -589,8 +589,13 @@
 
     if ( TRUE == getReservoirFillStatus( DG_RESERVOIR_1 ) )
     {
-        cmdSetDGActiveReservoir( DG_RESERVOIR_1 );
+        DG_SWITCH_RSRVRS_CMD_T rsrvrCmd;
 
+        rsrvrCmd.reservoirID            = (U32)DG_RESERVOIR_1;
+        rsrvrCmd.useLastTrimmerHeaterDC = FALSE;
+
+        cmdSetDGActiveReservoir( &rsrvrCmd );
+
         if ( TRUE == hasDGCompletedReservoirSwitch() )
         {
             U32 dialyzerDialysateVolume = getDialyzerDialysateVolume();
@@ -770,8 +775,13 @@
 
     if ( TRUE == getReservoirFillStatus( DG_RESERVOIR_2 ) )
     {
-        cmdSetDGActiveReservoir( DG_RESERVOIR_2 );
+        DG_SWITCH_RSRVRS_CMD_T rsrvrCmd;
 
+        rsrvrCmd.reservoirID            = (U32)DG_RESERVOIR_1;
+        rsrvrCmd.useLastTrimmerHeaterDC = FALSE;
+
+        cmdSetDGActiveReservoir( &rsrvrCmd );
+
         if ( TRUE == hasDGCompletedReservoirSwitch() )
         {
             signalBloodPumpHardStop();