Index: dialin/common/dg_defs.py
===================================================================
diff -u -r32e628abcbbd3fd70866505d9f2836a6f732ef06 -r22e33f3df569292eb7065c1325ca4460afbe36be
--- dialin/common/dg_defs.py	(.../dg_defs.py)	(revision 32e628abcbbd3fd70866505d9f2836a6f732ef06)
+++ dialin/common/dg_defs.py	(.../dg_defs.py)	(revision 22e33f3df569292eb7065c1325ca4460afbe36be)
@@ -177,13 +177,17 @@
     DG_HEAT_DISINFECT_STATE_FILL_R2_WITH_HOT_WATER = 12             # Heat disinfect, fill R2 with hot water state
     DG_HEAT_DISINFECT_STATE_DISINFECT_R2_TO_R1 = 13                 # Heat disinfect, disinfect R2 to R1 state
     DG_HEAT_DISINFECT_STATE_COOL_DOWN_HEATERS = 14                  # Heat disinfect, cool down heaters state
-    DG_HEAT_DISINFECT_STATE_MIX_DRAIN_R1 = 15                       # Heat disinfect, mix drain R1 state
-    DG_HEAT_DISINFECT_STATE_MIX_DRAIN_R2 = 16                       # Heat disinfect, mix drain R2 state
-    DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH = 17                  # Heat disinfect, cancel mode basic path state
-    DG_HEAT_DISINFECT_STATE_CANCEL_WATER_PATH = 18                  # Heat disinfect, cancel mode water path state
-    DG_HEAT_DISINFECT_STATE_COMPLETE = 19                           # Heat disinfect, complete state
-    DG_NELSON_HEAT_DISINFECT_STATE_FILL_R1_WITH_WATER = 20          # Heat disinfect, Nelson support state
-    NUM_OF_DG_HEAT_DISINFECT_STATES = 21                            # Number of heat disinfect mode states
+    DG_HEAT_DISINFECT_STATE_NOCTURNAL_COOL_IDLE = 15                # Heat disinfect, nocturnal cool idle state
+    DG_HEAT_DISINFECT_STATE_NOCTURNAL_COOL_CHECK_WATER_TEMP = 16    # Heat disinfect, nocturnal cool check water temp state
+    DG_HEAT_DISINFECT_STATE_NOCTURNAL_COOL_DRAIN_R1 = 17            # Heat disinfect, nocturnal cool drain R1 state
+    DG_HEAT_DISINFECT_STATE_NOCTURNAL_COOL_DRAIN_R2 = 18            # Heat disinfect, nocturnal cool drain R2 state
+    DG_HEAT_DISINFECT_STATE_MIX_DRAIN_R1 = 19                       # Heat disinfect, mix drain R1 state
+    DG_HEAT_DISINFECT_STATE_MIX_DRAIN_R2 = 20                       # Heat disinfect, mix drain R2 state
+    DG_HEAT_DISINFECT_STATE_CANCEL_BASIC_PATH = 21                  # Heat disinfect, cancel mode basic path state
+    DG_HEAT_DISINFECT_STATE_CANCEL_WATER_PATH = 22                  # Heat disinfect, cancel mode water path state
+    DG_HEAT_DISINFECT_STATE_COMPLETE = 23                           # Heat disinfect, complete state
+    DG_NELSON_HEAT_DISINFECT_STATE_FILL_R1_WITH_WATER = 24          # Heat disinfect, Nelson support state
+    NUM_OF_DG_HEAT_DISINFECT_STATES = 25                            # Number of heat disinfect mode states
 
 
 @unique
Index: tests/dg_tests.py
===================================================================
diff -u -r902a65965ca2f97fbb0186fdc01f9613b4f5076f -r22e33f3df569292eb7065c1325ca4460afbe36be
--- tests/dg_tests.py	(.../dg_tests.py)	(revision 902a65965ca2f97fbb0186fdc01f9613b4f5076f)
+++ tests/dg_tests.py	(.../dg_tests.py)	(revision 22e33f3df569292eb7065c1325ca4460afbe36be)
@@ -111,22 +111,25 @@
     state = 0
     state_elapsed_time = 0
     overall_elapsed_time = 0
+    nocturnal_mode = 0
     if dg.dg_operation_mode == 9:
         state = DGHeatDisinfectStates(dg.heat_disinfect.heat_disinfect_state).name
         overall_elapsed_time = dg.heat_disinfect.overall_elapsed_time
         state_elapsed_time = dg.heat_disinfect.state_elapsed_time
+        nocturnal_mode = dg.heat_disinfect.is_nocturnal_heat_disinfect_requested
     elif dg.dg_operation_mode == 12:
         state = DGHeatDisinfectActiveCoolStates(dg.heat_disinfect_active_cool.heat_disinfect_active_cool_state).name
         overall_elapsed_time = dg.heat_disinfect_active_cool.overall_elapsed_time
         state_elapsed_time = dg.heat_disinfect_active_cool.state_elapsed_time
 
     info = ('State, {}, Overall_elapsed_time, {}, State_elapsed_time, {}, Disinfect_RO_77, {}, Disinfect_RO_82, {}, '
             'Disinfect_R_77, {}, Disinfect_R_82, {}, R1_level, {:5.3f}, R2_level, {:5.3f}, Top_alarm, {}, UI_state, {},'
-            ' '
+            'Nocturnal, {}, '
             .format(state, overall_elapsed_time, state_elapsed_time, dg.heat_disinfect.disinfect_ro_77_time_s,
                     dg.heat_disinfect.disinfect_ro_82_time_s, dg.heat_disinfect.disinfect_r_77_time_s,
                     dg.heat_disinfect.disinfect_r_82_time_s, dg.heat_disinfect.r1_level, dg.heat_disinfect.r2_level,
-                    hd.alarms.alarm_top, DGHeatDisinfectUIStates(dg.heat_disinfect.heat_disinfect_ui_state).name))
+                    hd.alarms.alarm_top, DGHeatDisinfectUIStates(dg.heat_disinfect.heat_disinfect_ui_state).name,
+                    nocturnal_mode))
     return info
 
 
@@ -536,6 +539,7 @@
     # sleep(1)
     #dg.hd_proxy.cmd_start_stop_dg_heat_disinfect()
     #dg.hd_proxy.cmd_start_stop_dg_heat_disinfect_active_cool()
+    dg.hd_proxy.cmd_start_stop_nocturnal_dg_heat_disinfect()
 
     try:
         while True:
@@ -735,7 +739,7 @@
 
     #run_test_configs()
 
-    #run_heat_disinfect()
+    run_heat_disinfect()
 
     #run_flush_mode()
 
@@ -784,4 +788,4 @@
     #    sleep(0.5)
     #hd.test_configs.cmd_set_test_config(HDTestConfigOptions.TEST_CONFIG_SKIP_DISINFECT_AND_SERVICE_TX_BLOCKERS.value)
     #dg.cmd_dg_set_operation_mode(3)
-    hd.cmd_hd_set_operation_mode(1)
+    #hd.cmd_hd_set_operation_mode(1)