Index: firmware/App/Modes/ModeHeatDisinfect.c
===================================================================
diff -u -r25cf37f4d5b14032df202f99fad30af5be192e8d -r22234413805b8e67ec6aa288320288f8cd82e5dd
--- firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 25cf37f4d5b14032df202f99fad30af5be192e8d)
+++ firmware/App/Modes/ModeHeatDisinfect.c	(.../ModeHeatDisinfect.c)	(revision 22234413805b8e67ec6aa288320288f8cd82e5dd)
@@ -7,8 +7,8 @@
 *
 * @file    ModeHeatDisinfect.c
 *
-* @author  (last)      Bill Bracken
-* @date    (last)      26-Oct-2022
+* @author  (last)      Dara Navaei
+* @date    (last)      28-Oct-2022
 *
 * @author  (original)  Sean
 * @date    (original)  20-Apr-2020
@@ -558,7 +558,7 @@
     else if ( DG_RESERVOIR_NOT_REACHED_TARGET == rsrvr2Status )
     {
         prevHeatDisinfectState = state;
-        state = DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH;
+        state                  = DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH;
     }
 
     return state;
@@ -1090,8 +1090,12 @@
             // at inlet temperature > 45 C
             setROPumpTargetFlowRateLPM( HEAT_DISINFECT_TARGET_RO_FLOW_TRANSFER_LPM, HEAT_DISINFECT_MAX_RO_PRESSURE_PSI );
 
-             // Set the drain pump to control mode
+            // Set the drain pump to control mode
             setDrainPumpTargetOutletPressure( HEAT_DISINFECT_TARGET_DRAIN_FILL_R2_PSI );
+
+            // Turn off trimmer heater for transition
+            stopHeater(DG_TRIMMER_HEATER);
+
             // 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;
@@ -1154,6 +1158,10 @@
             // at inlet temperature > 45 C
             setROPumpTargetFlowRateLPM( HEAT_DISINFECT_TARGET_RO_FLOW_LPM, HEAT_DISINFECT_MAX_RO_PRESSURE_PSI );
 
+            // Start the trimmer heater since we are recirculating water and there is flow in the shunt line
+            setHeaterTargetTemperature( DG_TRIMMER_HEATER, HEAT_DISINFECT_TARGET_TEMPERATURE_C );
+            startHeater( DG_TRIMMER_HEATER );
+
             state = DG_HEAT_DISINFECT_STATE_DISINFECT_R2_TO_R1;
         }
         else if ( DG_RESERVOIR_NOT_REACHED_TARGET == rsrvr2Status )