diff --git a/applications/landlord_description_overrides/handler.py b/applications/landlord_description_overrides/handler.py
index dd37e461c..bc5fe8ee9 100644
--- a/applications/landlord_description_overrides/handler.py
+++ b/applications/landlord_description_overrides/handler.py
@@ -22,6 +22,7 @@ from domain.data_transformation.guarded_column_classifier import (
     GuardedColumnClassifier,
 )
 from domain.epc.property_overrides.water_heating_type import WaterHeatingType
+from domain.epc.property_overrides.water_heating_guard import water_heating_guard
 from domain.epc.property_overrides.wall_type import WallType
 from domain.epc.property_overrides.wall_type_construction_dates import (
     wall_type_construction_date_prompt_hint,
@@ -174,8 +175,16 @@ def _build_columns(
         "water_heating": lambda src: ClassifiableColumn(
             name="water_heating",
             source_column=src,
-            classifier=ChatGptColumnClassifier(
-                chat_gpt, WaterHeatingType, WaterHeatingType.UNKNOWN
+            # A biomass / wood / dual-fuel / biodiesel DHW description has no
+            # dedicated LLM target and was funnelled into "house coal"; the
+            # deterministic guard resolves the structured fuels (and the "electric
+            # immersion assumed" no-system case) and the LLM handles the rest
+            # (#1376, ADR-0043).
+            classifier=GuardedColumnClassifier(
+                guard=water_heating_guard,
+                fallback=ChatGptColumnClassifier(
+                    chat_gpt, WaterHeatingType, WaterHeatingType.UNKNOWN
+                ),
             ),
             repo=LandlordOverridesRepository[WaterHeatingType](
                 session, LandlordWaterHeatingOverrideRow