Index: firmware/App/Modes/ModeDrain.c
===================================================================
diff -u -r67da3f0d10e1143173b1e8c29061097d609d8623 -re5713fcc4511a625434a4748f7dded3d237acdf8
--- firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision 67da3f0d10e1143173b1e8c29061097d609d8623)
+++ firmware/App/Modes/ModeDrain.c	(.../ModeDrain.c)	(revision e5713fcc4511a625434a4748f7dded3d237acdf8)
@@ -7,8 +7,8 @@
 *
 * @file    ModeDrain.c
 *
-* @author  (last)      Dara Navaei
-* @date    (last)      27-Apr-2023
+* @author  (last)      Michael Garthwaite
+* @date    (last)      16-May-2023
 *
 * @author  (original)  Leonardo Baloa
 * @date    (original)  20-Dec-2019
@@ -113,6 +113,7 @@
 {
     // re-initialize each time we transition to drain mode
     initDrainMode();
+    setCurrentSubState( NO_SUB_STATE );
 
     DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
 
@@ -247,9 +248,20 @@
 {
     DG_DRAIN_STATE_T result             = DG_DRAIN_STATE_DRAIN;
     DG_RESERVOIR_ID_T inactiveReservoir = getInactiveReservoir();
+    U32 targetVolumeML                  = getTargetDrainVolumeML();
+    BOOL drainStatus                    = FALSE;
 
+    if ( 0 == targetVolumeML )
+    {
+        drainStatus = hasTargetDrainToZeroBeenReached( inactiveReservoir, DRAIN_WEIGHT_UNCHANGE_TIMEOUT_MS );
+    }
+    else
+    {
+        drainStatus = hasTargetDrainToVolumeBeenReached( inactiveReservoir, targetVolumeML, DRAIN_WEIGHT_UNCHANGE_TIMEOUT_MS );
+    }
+
     // if we have reached our target drain to volume (by weight) or cannot drain anymore, we are done draining - go back to generation idle mode
-    if ( TRUE == hasTargetDrainVolumeBeenReached( inactiveReservoir, DRAIN_WEIGHT_UNCHANGE_TIMEOUT_MS ) )
+    if ( TRUE == drainStatus )
     {
         DG_ACID_CONCENTRATES_RECORD_T acid;
         F32 acidBottleVolML;