diff --git a/tests/domain/epc/test_main_heating_system_overlay.py b/tests/domain/epc/test_main_heating_system_overlay.py
index e161dbf5..8b901616 100644
--- a/tests/domain/epc/test_main_heating_system_overlay.py
+++ b/tests/domain/epc/test_main_heating_system_overlay.py
@@ -53,6 +53,26 @@ def test_heating_archetypes_decode_to_their_sap_codes(
     assert simulation.heating.sap_main_heating_code == code
 
 
+@pytest.mark.parametrize(
+    ("main_heating_value", "code"),
+    [
+        ("Electric storage heaters, old", 401),
+        ("Electric storage heaters, slimline", 402),
+        ("Electric storage heaters, convector", 403),
+    ],
+)
+def test_storage_heater_subtypes_decode_to_their_codes(
+    main_heating_value: str, code: int
+) -> None:
+    # Act
+    simulation = main_heating_overlay_for(main_heating_value, 0)
+
+    # Assert
+    assert simulation is not None
+    assert simulation.heating is not None
+    assert simulation.heating.sap_main_heating_code == code
+
+
 @pytest.mark.parametrize(
     "main_heating_value",
     ["Unknown", "", "Air source heat pump", "Community heating"],