Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -r07589ffe861c73f9095c6b1536ec97ec2238fbce -r34d830c022c7d27c5f97e340f692b566efcfca89
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 07589ffe861c73f9095c6b1536ec97ec2238fbce)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 34d830c022c7d27c5f97e340f692b566efcfca89)
@@ -94,6 +94,7 @@
 #define HEAT_DISINFECT_TARGET_RO_FLOW_TRANSFER_LPM 0.8F                                                        ///< Heat disinfect target RO flow rate in L/min when transferring between reservoirs.
 #define HEAT_DISINFECT_MAX_RO_PRESSURE_PSI         30                                                          ///< Heat disinfect maximum RO pressure in psi.
 #define HEAT_DISINFECT_TARGET_DRAIN_PRES_PSI       12.0F                                                       ///< Heat disinfect target drain outlet pressure in psi.
+#define HEAT_DISINFECT_TARGET_DRAIN_FILL_R2_PSI    9.0F                                                        ///< Heat disinfect target drain R2 fill outplet pressure in PSI
 #define HEAT_DISINFECT_TIME_MS                     ( 10 * SEC_PER_MIN * MS_PER_SECOND )                        ///< Heat disinfect time for each section in milliseconds.
 #define HEAT_DISINFECT_START_TEMP_TIMOUT_MS        ( 4 * MIN_PER_HOUR * SEC_PER_MIN * MS_PER_SECOND )          ///< Heat disinfect reaching to minimum temperature timeout in milliseconds.
 #define RSRVRS_TARGET_VOL_OUT_TIMEOUT_MS           ( 10 * MS_PER_SECOND )                                      ///< Reservoirs 1 & 2 maximum volume out of range timeout during heat disinfect.
@@ -1141,8 +1142,8 @@
             setROPumpTargetFlowRateLPM( HEAT_DISINFECT_TARGET_RO_FLOW_TRANSFER_LPM, HEAT_DISINFECT_MAX_RO_PRESSURE_PSI );
 
              // Set the drain pump to control mode
-            setDrainPumpTargetOutletPressure( 9.0F );
-           // Although there is fluid in both reservoirs, but they are set to empty
+            setDrainPumpTargetOutletPressure( HEAT_DISINFECT_TARGET_DRAIN_FILL_R2_PSI );
+            // Although there is fluid in both reservoirs, but they are set to empty
             // to begin the transition of hot water from R1 to R2.
             rsrvr2Status            = DG_RESERVOIR_BELOW_TARGET;
             rsrvr1Status            = DG_RESERVOIR_BELOW_TARGET;