Index: firmware/App/Modes/ModeFill.c
===================================================================
diff -u -r778c16d5c83e4af29aa9c0e8eb46386c16f60778 -r361b15bf5153656eace8665812ac2a6d2b2fc424
--- firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 778c16d5c83e4af29aa9c0e8eb46386c16f60778)
+++ firmware/App/Modes/ModeFill.c	(.../ModeFill.c)	(revision 361b15bf5153656eace8665812ac2a6d2b2fc424)
@@ -234,18 +234,20 @@
 U32 transitionToFillMode( void )
 {
     F32 targetFlowLPM = getTargetFillFlowRateLPM();
+    DG_FILL_MODE_STATE_T restoreFillState = fillState;                                                                       ///< Last active fill state.
 
+    initFillMode();                                                                                                          // Reset the state machine
     if ( ( getTestConfigStatus( TEST_CONFIG_RECOVER_TREATMENT ) != TRUE ) || ( getPreviousOperationMode() != DG_MODE_FAUL ) )
     {
-        initFillMode();
         setCurrentSubState( NO_SUB_STATE );
-
         // Set initial actuator states
         setValveState( VDR, VALVE_STATE_DRAIN_C_TO_NO );
         setValveState( VPO, VALVE_STATE_NOFILL_C_TO_NO );
     }
     else
-    {
+    { // Restore the prior fillstate to a valid, running fill state, with timer state reset.
+        fillState = restoreFillState;
+
         setValveState( VPI, VALVE_STATE_OPEN );
         setValveState( VPD, VALVE_STATE_OPEN_C_TO_NC );