diff --git a/custom_components/nilan/registers.py b/custom_components/nilan/registers.py
index 3e64d16..50ba6de 100644
--- a/custom_components/nilan/registers.py
+++ b/custom_components/nilan/registers.py
@@ -85,6 +85,13 @@ class CTS602InputRegisters:
 
     compressor_type = 1500
 
+    hps_alarm_count = 1600
+    hps_alarm_count_active = 1601
+    hps_alarm_level = 1602
+    hps_alarm_code1 = 1604
+    hps_alarm_code2 = 1605
+    hps_alarm_code3 = 1606
+
     hot_water_type = 1700
     hot_water_anode_state = 1701
 
@@ -495,7 +502,7 @@ class CTS602HoldingRegisters:
     hps_defrost_t_rel_frost = 6598
     hps_defrost_max_time = 6599
     hps_defrost_min_interval = 6600
-    hps_defrost_max_time = 6601
+    hps_defrost_stop_time = 6601
     hps_defrost_defrost_cap = 6602
 
     control_smart_grid_on = 6604