diff --git a/luxtronik/datatypes.py b/luxtronik/datatypes.py
index d8834351..2543e011 100755
--- a/luxtronik/datatypes.py
+++ b/luxtronik/datatypes.py
@@ -150,6 +150,13 @@ def options(cls):
         """Return list of all available options."""
         return [value for _, value in cls.codes.items()]
 
+    @classmethod
+    def sanitize_option(cls, option):
+        is_string = isinstance(option, str)
+        if is_string:
+            option = option.lower().replace('-', '_').strip()
+        return option, is_string
+
     @classmethod
     def from_heatpump(cls, value):
         if value is None:
@@ -160,12 +167,14 @@ def from_heatpump(cls, value):
 
     @classmethod
     def to_heatpump(cls, value):
+        value, value_is_str = cls.sanitize_option(value)
         for index, code in cls.codes.items():
+            code, _ = cls.sanitize_option(code)
             if code == value:
                 return index
-        if isinstance(value, str) and value.startswith(cls.unknown_prefix):
-            return int(value.split(cls.unknown_delimiter)[1])
-        if isinstance(value, (int, float)) or (isinstance(value, str) and value.isdigit()):
+        if value_is_str and value.startswith(cls.unknown_prefix.lower()):
+            return int(value.split(cls.unknown_delimiter.lower())[1])
+        if isinstance(value, (int, float)) or (value_is_str and value.isdigit()):
             return int(value)
         return None
 
diff --git a/tests/test_datatypes.py b/tests/test_datatypes.py
index 79ba895e..5da5cc7e 100644
--- a/tests/test_datatypes.py
+++ b/tests/test_datatypes.py
@@ -233,6 +233,7 @@ def test_to_heatpump(self):
         a = SelectionBase("")
         assert a.to_heatpump("a") is None
         assert a.to_heatpump("Unknown_214") == 214
+        assert a.to_heatpump("unknown_215") == 215
         assert a.to_heatpump(0) == 0
         assert a.to_heatpump("1") == 1
         assert a.to_heatpump(2.3) == 2
@@ -244,8 +245,8 @@ class SelectionBaseChild(SelectionBase):
 
     codes = {
         0: "a",
-        1: "b",
-        2: "c",
+        1: "B",
+        2: "c_d",
     }
 
 
@@ -272,8 +273,8 @@ def test_from_heatpump(self):
 
         a = SelectionBaseChild("")
         assert a.from_heatpump(0) == "a"
-        assert a.from_heatpump(1) == "b"
-        assert a.from_heatpump(2) == "c"
+        assert a.from_heatpump(1) == "B"
+        assert a.from_heatpump(2) == "c_d"
         assert a.from_heatpump(3) == "Unknown_3"
         assert a.from_heatpump(None) is None
 
@@ -281,9 +282,9 @@ def test_to_heatpump(self):
         """Test cases for to_heatpump function"""
 
         a = SelectionBaseChild("")
-        assert a.to_heatpump("a") == 0
-        assert a.to_heatpump("b") == 1
-        assert a.to_heatpump("c") == 2
+        assert a.to_heatpump(" a") == 0
+        assert a.to_heatpump("b ") == 1
+        assert a.to_heatpump("c-D ") == 2
         assert a.to_heatpump("d") is None
         assert a.to_heatpump(None) is None
         assert a.to_heatpump(2) == 2