diff --git a/datatypes/epc/domain/tests/test_from_site_notes.py b/datatypes/epc/domain/tests/test_from_site_notes.py
index c31793982..b8f6a1377 100644
--- a/datatypes/epc/domain/tests/test_from_site_notes.py
+++ b/datatypes/epc/domain/tests/test_from_site_notes.py
@@ -1223,6 +1223,31 @@ class TestSecondaryHeatingTypeCoding:
             EpcPropertyDataMapper.from_site_notes(survey)
 
 
+class TestSecondaryFuelTypeCodingDualFuel:
+    """The secondary-heating survey field lodges the dual-fuel appliance
+    title-cased ("Dual Fuel Appliance (Mineral and Wood)"), unlike the
+    sentence-case main-fuel label already mapped — exact-string lookups, so
+    both tables need their own entry. Same physical fuel, same Table 32
+    code 10 the main-fuel path pins."""
+
+    def test_title_case_dual_fuel_maps_to_table_32_code_10(self) -> None:
+        # Arrange
+        data = load("pashub_rdsap_site_notes_example1.json")
+        data["heating_and_hot_water"]["secondary_heating"][
+            "secondary_fuel"
+        ] = "Dual Fuel Appliance (Mineral and Wood)"
+        data["heating_and_hot_water"]["secondary_heating"][
+            "secondary_system"
+        ] = "Open fire in grate"
+        survey = from_dict(PasHubRdSapSiteNotes, data)
+
+        # Act
+        result = EpcPropertyDataMapper.from_site_notes(survey)
+
+        # Assert
+        assert result.sap_heating.secondary_fuel_type == 10
+
+
 class TestSecondaryFuelTypeCoding:
     """`from_site_notes` must int-code the PAS Hub secondary-heating
     `secondary_fuel` label to the SAP 10.2 Table 32 `secondary_fuel_type`