diff --git a/domain/epc/property_overlays/main_heating_system_overlay.py b/domain/epc/property_overlays/main_heating_system_overlay.py
index e763fea75..14ca6b6bf 100644
--- a/domain/epc/property_overlays/main_heating_system_overlay.py
+++ b/domain/epc/property_overlays/main_heating_system_overlay.py
@@ -109,6 +109,7 @@ _MAIN_HEATING_CODES: dict[str, int] = {
     "Electric storage heaters, fan": 404,
     "Direct-acting electric": 191,
     "Electric room heaters": 691,
+    "Solid fuel room heater, closed": 633,
 }
 
 
diff --git a/domain/epc/property_overrides/main_heating_system_type.py b/domain/epc/property_overrides/main_heating_system_type.py
index 3bfff01e5..2ea81c924 100644
--- a/domain/epc/property_overrides/main_heating_system_type.py
+++ b/domain/epc/property_overrides/main_heating_system_type.py
@@ -25,4 +25,5 @@ class MainHeatingSystemType(Enum):
     ELECTRIC_STORAGE_FAN = "Electric storage heaters, fan"
     DIRECT_ELECTRIC = "Direct-acting electric"
     ELECTRIC_ROOM_HEATERS = "Electric room heaters"
+    SOLID_FUEL_ROOM_HEATER_CLOSED = "Solid fuel room heater, closed"
     UNKNOWN = "Unknown"