diff --git a/custom_components/versatile_thermostat/config_schema.py b/custom_components/versatile_thermostat/config_schema.py
index 701d44e..0e199d2 100644
--- a/custom_components/versatile_thermostat/config_schema.py
+++ b/custom_components/versatile_thermostat/config_schema.py
@@ -230,8 +230,16 @@ STEP_TPI_DATA_SCHEMA = vol.Schema(  # pylint: disable=invalid-name
 
 STEP_CENTRAL_TPI_DATA_SCHEMA = vol.Schema(  # pylint: disable=invalid-name
     {
-        vol.Required(CONF_TPI_COEF_INT, default=0.6): vol.Coerce(float),
-        vol.Required(CONF_TPI_COEF_EXT, default=0.01): vol.Coerce(float),
+        vol.Required(CONF_TPI_COEF_INT, default=0.6): selector.NumberSelector(
+            selector.NumberSelectorConfig(
+                min=0.0, max=1.0, step=0.01, mode=selector.NumberSelectorMode.BOX
+            )
+        ),
+        vol.Required(CONF_TPI_COEF_EXT, default=0.01): selector.NumberSelector(
+            selector.NumberSelectorConfig(
+                min=0.0, max=1.0, step=0.01, mode=selector.NumberSelectorMode.BOX
+            )
+        ),
     }
 )