diff --git a/datatypes/epc/domain/tests/test_from_site_notes.py b/datatypes/epc/domain/tests/test_from_site_notes.py
index 8ecfa96c2..c31793982 100644
--- a/datatypes/epc/domain/tests/test_from_site_notes.py
+++ b/datatypes/epc/domain/tests/test_from_site_notes.py
@@ -1192,6 +1192,10 @@ class TestSecondaryHeatingTypeCoding:
                 "sealed to fireplace",
                 603,
             ),
+            # Pre-1980 open-fronted gas fire on an open flue, NOT sealed to
+            # the fireplace (no qualifier in the label) — PCDB 601, eff 50%;
+            # 602 (with back boiler) rejected, no back-boiler qualifier.
+            ("Pre 1980 - Open front fire with open flue", 601),
             # Solid fuel (PCDB 631, eff 0.32 col B).
             ("Open fire in grate", 631),
             ("No Secondary Heating", None),  # no secondary heater lodged