Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -r6f1f269cd7d91f41c51797d17a85a7ea249e21f3 -rdf0a0b9ce1414b00b381e516714f9089d8e4ae21
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 6f1f269cd7d91f41c51797d17a85a7ea249e21f3)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision df0a0b9ce1414b00b381e516714f9089d8e4ae21)
@@ -64,7 +64,9 @@
 #define FLUSH_CICRCULATION_WAIT_TIME_MS            ( 30 * MS_PER_SECOND )                                      ///< Flush/rinse circulation path wait time in milliseconds. TODO original time was 30 seconds
 #define MAX_FLUSH_CIRC_TEMP_SENSOR_DIFF_C          50.0                                                        ///< Maximum flush circulation temperature difference tolerance in C. TODO original difference was 3.0 degrees
 #define NUM_OF_TEMP_SENSORS_TO_AVG                 4.0                                                         ///< Number of temperature sensors to average to check the difference.
-#define ACID_PUMP_SPEED_ML_PER_MIN        -30.0                                                       ///< Concentrate pumps reverse speed in mL/min.
+#define ACID_PUMP_SPEED_ML_PER_MIN                 -30.0                                                       ///< Acid concentrate pump speed in mL/min.
+// The bicarb pump is 2% faster than the acid pump to create a flow from acid to bicarb line during heat disinfect
+#define BICARB_PUMP_SPEED_ML_PER_MIN                30.6                                                       ///< Bicarb concentrate pump speed in mL/min.
 
 // Flush and drain R1 and R2
 #define RSRVRS_FULL_VOL_ML                         1750.0                                                      ///< Reservoirs 1 & 2 full volume in mL. TODo original value was 1900
@@ -118,7 +120,8 @@
 /// Heat disinfect status
 typedef enum Heat_disinfect_status
 {
-    HEAT_DISINFECT_IN_PROGRESS = 0,                                                                            ///< Heat disinfect in progress.
+    HEAT_DISINFECT_HEAT_UP_IN_PROGRESS = 0,                                                                    ///< Heat disinfect in progress.
+    HEAT_DISINFECT_DISINFECT_IN_PROGRESS,                                                                      ///< Heat disinfect disinfect in progress.
     HEAT_DISINFECT_RSRVRS_LEAK_TIMEOUT,                                                                        ///< Heat disinfect reservoirs leak timeout.
     HEAT_DISINFECT_HEAT_UP_TIMEOUT,                                                                            ///< Heat disinfect heat up timeout.
     HEAT_DISINFECT_COMPLETE,                                                                                   ///< Heat disinfect complete.
@@ -1124,6 +1127,10 @@
             state = DG_HEAT_DISINFECT_STATE_CANCEL_WATER_PATH;
             break;
 
+        case HEAT_DISINFECT_DISINFECT_IN_PROGRESS:
+            heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_DISINFECT_RESERVOIR_1;
+            break;
+
         case HEAT_DISINFECT_COMPLETE:
 
             requestConcentratePumpsOff( CONCENTRATEPUMPS_CP1_ACID );
@@ -1147,9 +1154,9 @@
             state = DG_HEAT_DISINFECT_STATE_FILL_R2_WITH_HOT_WATER;
             break;
 
-        case HEAT_DISINFECT_IN_PROGRESS:
+        case HEAT_DISINFECT_HEAT_UP_IN_PROGRESS:
         default:
-            // Do nothing, heat disinfect is in progress
+            heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_HEAT_UP_WATER;
             break;
     }
 
@@ -1223,6 +1230,7 @@
 {
     DG_HEAT_DISINFECT_STATE_T state = DG_HEAT_DISINFECT_STATE_DISINFECT_R2_TO_R1;
     HEAT_DISINFECT_STATUS_T status  = getHeatDisinfectStatus();
+    heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_DISINFECT_RESERVOIR_2;
 
     switch ( status )
     {
@@ -1239,7 +1247,7 @@
             state = DG_HEAT_DISINFECT_STATE_COOL_DOWN_HEATERS;
             break;
 
-        case HEAT_DISINFECT_IN_PROGRESS:
+        case HEAT_DISINFECT_HEAT_UP_IN_PROGRESS:
         default:
             // Do nothing heat disinfect is in progress.
             break;
@@ -1966,7 +1974,7 @@
  *************************************************************************/
 static HEAT_DISINFECT_STATUS_T getHeatDisinfectStatus( void )
 {
-    HEAT_DISINFECT_STATUS_T status = HEAT_DISINFECT_IN_PROGRESS;
+    HEAT_DISINFECT_STATUS_T status = HEAT_DISINFECT_HEAT_UP_IN_PROGRESS;
 
     F32 TPoTemp = getTemperatureValue( TEMPSENSORS_OUTLET_PRIMARY_HEATER );
     F32 ThdTemp = getTemperatureValue( TEMPSENSORS_HEAT_DISINFECT );
@@ -2004,7 +2012,6 @@
         // Keep reseting the disinfect timer so the elapsed time is always 0 until disinfect truly starts
         heatDisinfectTimer           = getMSTimerCount();
         isPartialDisinfectInProgress = FALSE;
-        heatDisinfectUIState         = HEAT_DISINFECT_UI_STATE_HEAT_UP_WATER;
         targetDisinfectTime          = 0;
 
         if ( TRUE == didTimeout( stateTimer, HEAT_DISINFECT_START_TEMP_TIMOUT_MS ) )
@@ -2020,25 +2027,21 @@
         heatDisinfectTimer           = getMSTimerCount();
         isPartialDisinfectInProgress = TRUE;
         targetDisinfectTime          = HEAT_DISINFECT_TIME_MS;
+        status = HEAT_DISINFECT_DISINFECT_IN_PROGRESS;
 
-        // Set the heat disinfect UI state
+        // In disinfect R1 to R2, concentrate pumps are also run
         if ( DG_HEAT_DISINFECT_STATE_DISINFECT_R1_TO_R2 == heatDisinfectState )
         {
-            heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_DISINFECT_RESERVOIR_1;
 #ifndef IGNORE_CONC_PUMP_IN_HEAT_DISINFECT
             // Turn the pumps on in reverse
             setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP1_ACID,   ACID_PUMP_SPEED_ML_PER_MIN );
-            setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, ACID_PUMP_SPEED_ML_PER_MIN );
+            setConcentratePumpTargetSpeed( CONCENTRATEPUMPS_CP2_BICARB, BICARB_PUMP_SPEED_ML_PER_MIN );
 
             // During R1 to R2 disinfect, the concentrate pumps turn on
             requestConcentratePumpsOn( CONCENTRATEPUMPS_CP1_ACID );
             requestConcentratePumpsOn( CONCENTRATEPUMPS_CP2_BICARB );
 #endif
         }
-        else
-        {
-            heatDisinfectUIState = HEAT_DISINFECT_UI_STATE_DISINFECT_RESERVOIR_2;
-        }
     }
 
     // If heat disinfect temperature has been reached, check if this stage of heat disinfect is done
@@ -2086,7 +2089,7 @@
             U32 countDown = ( HEAT_DISINFECT_TIME_MS == targetDisinfectTime ? ( targetDisinfectTime - calcTimeSince( heatDisinfectTimer) ) : 0 );
 
             uiData.heatDisinfectTargetTime    = targetDisinfectTime;
-            uiData.heatDisinfectCountdownTime = countDown;
+            uiData.heatDisinfectCountdownTime = countDown / 1000; // The count down is converted into seconds since the UI does not work with milliseconds
             data.R1FillLevel                  = R1HeatDisinfectVol;
             data.R2FillLevel                  = R2HeatDisinfectVol;
         }