Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -rff676a9640e5dfe162de78d2b24f356f63bad5bb -reeaab2a9a685fb18845888d91040d3aa01977f6d
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision ff676a9640e5dfe162de78d2b24f356f63bad5bb)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision eeaab2a9a685fb18845888d91040d3aa01977f6d)
@@ -7,8 +7,8 @@
 *
 * @file    ModeHeatDisinfect.c
 *
-* @author  (last)      Dara Navaei
-* @date    (last)      15-Mar-2023
+* @author  (last)      Michael Garthwaite
+* @date    (last)      16-May-2023
 *
 * @author  (original)  Sean
 * @date    (original)  20-Apr-2020
@@ -79,6 +79,7 @@
 #define RSRVRS_DRAIN_TIMEOUT_MS                    ( 2 * SEC_PER_MIN * MS_PER_SECOND )                         ///< Reservoirs 1 & 2 drain timeout in ms.
 
 // Target temperature
+#define HEAT_DISINFECT_PRIM_HEATER_FLUSH_TARGET_TEMP_C 60.0F                                                   ///< Heat disinfect primary heater flush target temperature C.
 #define HEAT_DISINFECT_PRIM_HEATER_TARGET_TEMP_C   90.0F                                                       ///< Heat disinfect primary heater target temperature in C.
 #define HEAT_DISINFECT_TRIM_HEATER_TARGET_TEMP_C   90.0F                                                       ///< Heat disinfect trimmer heater target temperature in C.
 #define HEAT_DISINFECT_CONC_PUMPS_START_TEMP_C     75.0F                                                       ///< Heat disinfect start concentrate pumps target temperature in C.
@@ -317,7 +318,7 @@
     deenergizeActuators( NO_PARK_CONC_PUMPS );
 
     initHeatDisinfectMode();
-
+    setCurrentSubState( NO_SUB_STATE );
     setCPLDCleanLEDColor( CPLD_CLEAN_LED_ORANGE );
 
     return heatDisinfectState;
@@ -551,7 +552,7 @@
     else if ( DG_RESERVOIR_NOT_REACHED_TARGET == rsrvr1Status )
     {
         prevHeatDisinfectState = state;
-        state                  = DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH;
+        state                  = DG_HEAT_DISINFECT_STATE_CANCEL_WATER_PATH;
     }
 
     return state;
@@ -604,7 +605,7 @@
     else if ( DG_RESERVOIR_NOT_REACHED_TARGET == rsrvr2Status )
     {
         prevHeatDisinfectState = state;
-        state                  = DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH;
+        state                  = DG_HEAT_DISINFECT_STATE_CANCEL_WATER_PATH;
     }
 
     return state;
@@ -724,7 +725,7 @@
             if ( nelsonSupport != NELSON_INOCULATE )
 #endif
             {
-                setHeaterTargetTemperature( DG_PRIMARY_HEATER, HEAT_DISINFECT_PRIM_HEATER_TARGET_TEMP_C );
+                setHeaterTargetTemperature( DG_PRIMARY_HEATER, HEAT_DISINFECT_PRIM_HEATER_FLUSH_TARGET_TEMP_C );
                 startHeater( DG_PRIMARY_HEATER );
             }
 
@@ -877,7 +878,7 @@
             turnOffUVReactor( OUTLET_UV_REACTOR );
             // Set the valves to drain R2 and no fill
             setValveState( VPI, VALVE_STATE_CLOSED );
-            setValveState( VPD, VALVE_STATE_OPEN_C_TO_NC );
+            setValveState( VPD, VALVE_STATE_DRAIN_C_TO_NO );
             setValveState( VPO, VALVE_STATE_FILL_C_TO_NC );
             setValveState( VRO, VALVE_STATE_R1_C_TO_NO );
             setValveState( VRD2, VALVE_STATE_OPEN );