diff --git a/backend/documents_parser/tests/test_end_to_end.py b/backend/documents_parser/tests/test_end_to_end.py
index b994cd11..428d2cad 100644
--- a/backend/documents_parser/tests/test_end_to_end.py
+++ b/backend/documents_parser/tests/test_end_to_end.py
@@ -270,3 +270,6 @@ class TestPdfToEpcPropertyDataFixture2:
 
     def test_cylinder_size(self, result: EpcPropertyData) -> None:
         assert result.sap_heating.cylinder_size == "Normal (90-130 litres)"
+
+    def test_secondary_heating_type(self, result: EpcPropertyData) -> None:
+        assert result.sap_heating.secondary_heating_type == "Open fire in grate"
diff --git a/datatypes/epc/domain/epc_property_data.py b/datatypes/epc/domain/epc_property_data.py
index f0d8607d..563ceb31 100644
--- a/datatypes/epc/domain/epc_property_data.py
+++ b/datatypes/epc/domain/epc_property_data.py
@@ -64,7 +64,7 @@ class SapHeating:
     cylinder_insulation_type: Optional[int] = None
     cylinder_thermostat: Optional[str] = None
     secondary_fuel_type: Optional[int] = None
-    secondary_heating_type: Optional[int] = None
+    secondary_heating_type: Optional[Union[int, str]] = None  # int from API; str from site notes
     cylinder_insulation_thickness_mm: Optional[int] = None