Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -rfe42a5c1ddc26a2a2a784d0efd3a27d4e54d83fe -re1ed5c391f61f1c4ec569445063d4731ce53bd17
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision fe42a5c1ddc26a2a2a784d0efd3a27d4e54d83fe)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision e1ed5c391f61f1c4ec569445063d4731ce53bd17)
@@ -1,20 +1,22 @@
 /**************************************************************************
 *
-* Copyright (c) 2019-2021 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2019-2022 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * @file    ModeHeatDisinfect.c
 *
-* @author  (last)      Sean Nash
-* @date    (last)      12-Nov-2021
+* @author  (last)      Dara Navaei
+* @date    (last)      21-Dec-2021
 *
 * @author  (original)  Sean
 * @date    (original)  20-Apr-2020
 *
 ***************************************************************************/
 
+#include <math.h>   // For fabs
+
 #include "ConcentratePumps.h"
 #include "ConductivitySensors.h"
 #include "DrainPump.h"
@@ -84,9 +86,9 @@
 #define HEAT_DISINFECT_START_TEMPERATURE_C         81.0                                                        ///< Heat disinfect minimum acceptable temperature in C.
 
 // R1 to R2 & R2 to R1 heat disinfect circulation
-#define HEAT_DISINFECT_TARGET_RO_FLOW_LPM          1.3                                                         ///< Heat disinfect target RO flow rate in L/min.
-#define HEAT_DISINFECT_MAX_RO_PRESSURE_PSI         30                                                          ///< Heat disinfect maximum RO pressure in psi.
-#define HEAT_DISINFECT_TARGET_DRAIN_PRES_PSI       12.0                                                        ///< Heat disinfect target drain outlet pressure in psi.
+#define HEAT_DISINFECT_TARGET_RO_FLOW_LPM          1.5   // TODO this was 1.3                                                      ///< Heat disinfect target RO flow rate in L/min.
+#define HEAT_DISINFECT_MAX_RO_PRESSURE_PSI         45    // TODO this was 30                                                      ///< Heat disinfect maximum RO pressure in psi.
+#define HEAT_DISINFECT_TARGET_DRAIN_PRES_PSI       15.0   // TOD was 12                                                     ///< Heat disinfect target drain outlet 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           ( 0.5 * SEC_PER_MIN * MS_PER_SECOND )                       ///< Reservoirs 1 & 2 maximum volume out of range timeout during heat disinfect. TODO change this to 5 seconds
@@ -607,9 +609,8 @@
     if ( TRUE == didTimeout( stateTimer, FLUSH_DRAIN_WAIT_TIME_MS ) )
     {
         // If the inlet temperature and conductivity are in range, move onto the next state
-        //if ( ( getTemperatureValue( TEMPSENSORS_INLET_PRIMARY_HEATER ) > MIN_INLET_TEMPERATURE_C ) &&
-        //     ( getConductivityValue( CONDUCTIVITYSENSORS_CPI_SENSOR )  <=  MAX_INLET_CONDUCTIVITY_US_PER_CM ) )
-        if ( TRUE ) // TODO enable the conductivity check
+        if ( ( getTemperatureValue( TEMPSENSORS_INLET_PRIMARY_HEATER ) > MIN_INLET_TEMPERATURE_C ) &&
+             ( getConductivityValue( CONDUCTIVITYSENSORS_CPI_SENSOR )  <=  MAX_INLET_CONDUCTIVITY_US_PER_CM ) )
         {
             setValveState( VPD, VALVE_STATE_OPEN_C_TO_NC );
             setROPumpTargetFlowRateLPM( RO_PUMP_TARGET_FLUSH_FILL_FLOW_RATE_LPM, MAX_RO_PUMP_FLUSH_FILL_PRESSURE_PSI );