diff --git a/custom_components/versatile_thermostat/config_flow.py b/custom_components/versatile_thermostat/config_flow.py
index 024c75a..b8404f4 100644
--- a/custom_components/versatile_thermostat/config_flow.py
+++ b/custom_components/versatile_thermostat/config_flow.py
@@ -145,23 +145,34 @@ class VersatileThermostatBaseConfigFlow(FlowHandler):
         """True of the valve regulation mode is selected"""
         return infos.get(CONF_AUTO_REGULATION_MODE, None) == CONF_AUTO_REGULATION_VALVE
 
-    def check_valve_regulation_nb_entities(self, data: dict) -> bool:
+    def check_valve_regulation_nb_entities(self, data: dict, step_id=None) -> bool:
         """Check the number of entities for Valve regulation"""
+        underlyings_to_check = data if step_id == "type" else self._infos
+        regulation_infos_to_check = (
+            data if step_id == "valve_regulation" else self._infos
+        )
+
         ret = True
-        if self.is_valve_regulation_selected(self._infos):
-            nb_unders = len(self._infos.get(CONF_UNDERLYING_LIST))
-            nb_offset = len(data.get(CONF_OFFSET_CALIBRATION_LIST, []))
-            nb_opening = len(data.get(CONF_OPENING_DEGREE_LIST, []))
-            nb_closing = len(data.get(CONF_CLOSING_DEGREE_LIST, []))
+        if self.is_valve_regulation_selected(underlyings_to_check):
+            nb_unders = len(underlyings_to_check.get(CONF_UNDERLYING_LIST))
+            nb_offset = len(
+                regulation_infos_to_check.get(CONF_OFFSET_CALIBRATION_LIST, [])
+            )
+            nb_opening = len(
+                regulation_infos_to_check.get(CONF_OPENING_DEGREE_LIST, [])
+            )
+            nb_closing = len(
+                regulation_infos_to_check.get(CONF_CLOSING_DEGREE_LIST, [])
+            )
             if (
-                nb_unders != nb_offset
-                or nb_unders != nb_opening
-                or nb_unders != nb_closing
+                nb_unders != nb_opening
+                or (nb_unders != nb_offset and nb_offset > 0)
+                or (nb_unders != nb_closing and nb_closing > 0)
             ):
                 ret = False
         return ret
 
-    async def validate_input(self, data: dict, _) -> None:
+    async def validate_input(self, data: dict, step_id) -> None:
         """Validate the user input allows us to connect.
 
         Data has the keys from STEP_*_DATA_SCHEMA with values provided by the user.
@@ -239,7 +250,7 @@ class VersatileThermostatBaseConfigFlow(FlowHandler):
 
         # Check that the number of offet_calibration and opening_degree and closing_degree are equals
         # to the number of underlying entities
-        if not self.check_valve_regulation_nb_entities(data):
+        if not self.check_valve_regulation_nb_entities(data, step_id):
             raise ValveRegulationNbEntitiesIncorrect()
 
     def check_config_complete(self, infos) -> bool:
diff --git a/custom_components/versatile_thermostat/underlyings.py b/custom_components/versatile_thermostat/underlyings.py
index 40691c4..421fa3f 100644
--- a/custom_components/versatile_thermostat/underlyings.py
+++ b/custom_components/versatile_thermostat/underlyings.py
@@ -875,7 +875,7 @@ class UnderlyingValve(UnderlyingEntity):
         hass: HomeAssistant,
         thermostat: Any,
         valve_entity_id: str,
-        type: UnderlyingEntityType = UnderlyingEntityType.VALVE,
+        entity_type: UnderlyingEntityType = UnderlyingEntityType.VALVE,
     ) -> None:
         """Initialize the underlying valve"""
 
@@ -1039,7 +1039,7 @@ class UnderlyingValveRegulation(UnderlyingValve):
             hass,
             thermostat,
             opening_degree_entity_id,
-            type=UnderlyingEntityType.VALVE_REGULATION,
+            entity_type=UnderlyingEntityType.VALVE_REGULATION,
         )
         self._offset_calibration_entity_id = offset_calibration_entity_id
         self._opening_degree_entity_id = opening_degree_entity_id