diff --git a/domain/epc/property_overlays/water_heating_overlay.py b/domain/epc/property_overlays/water_heating_overlay.py
index 290182c50..61b6a159f 100644
--- a/domain/epc/property_overlays/water_heating_overlay.py
+++ b/domain/epc/property_overlays/water_heating_overlay.py
@@ -26,10 +26,18 @@ _WATER_HEATING_CODES: dict[str, tuple[int, int]] = {
     "From main system, LPG (bulk)": (901, 27),
     "From main system, bottled LPG": (901, 3),
     "From main system, house coal": (901, 33),
-    # Wood logs — RdSAP water_heating_fuel 6 (biomass ~0.028 kgCO2/kWh), from
-    # main (901). A wood-fired individual-main dwelling's DHW must not fall to
-    # house coal 33 (~0.395), a ~14x carbon overstatement (ADR-0043).
+    # Biomass / wood water fuels routed off the house-coal dumping ground
+    # (ADR-0043), all from main (901) with their own RdSAP water_heating_fuel:
+    #   6  wood logs (biomass ~0.028 kgCO2/kWh vs house coal 33 ~0.395)
+    #   9  dual fuel (mineral + wood)
+    #   31 biomass (community) — scored via the coherent community main; the
+    #      fuel is still emitted so an individual main would score biomass
+    #   34 biodiesel (community)
+    # A wood-fired individual-main dwelling's DHW must never fall to coal 33.
     "From main system, wood logs": (901, 6),
+    "From main system, dual fuel (mineral and wood)": (901, 9),
+    "From main system, biomass (community)": (901, 31),
+    "From main system, biodiesel (community)": (901, 34),
     "Electric immersion, electricity": (903, 29),
     # "boiler/circulator for water heating only" — SAP Table 4a code 911 (gas).
     "Gas boiler/circulator, mains gas": (911, 26),
diff --git a/domain/epc/property_overrides/water_heating_type.py b/domain/epc/property_overrides/water_heating_type.py
index 32e929acb..92cd3a75b 100644
--- a/domain/epc/property_overrides/water_heating_type.py
+++ b/domain/epc/property_overrides/water_heating_type.py
@@ -22,6 +22,9 @@ class WaterHeatingType(Enum):
     FROM_MAIN_BOTTLED_LPG = "From main system, bottled LPG"
     FROM_MAIN_HOUSE_COAL = "From main system, house coal"
     FROM_MAIN_WOOD_LOGS = "From main system, wood logs"
+    FROM_MAIN_DUAL_FUEL_MINERAL_WOOD = "From main system, dual fuel (mineral and wood)"
+    FROM_MAIN_BIOMASS_COMMUNITY = "From main system, biomass (community)"
+    FROM_MAIN_BIODIESEL_COMMUNITY = "From main system, biodiesel (community)"
     ELECTRIC_IMMERSION = "Electric immersion, electricity"
     GAS_BOILER_CIRCULATOR_MAINS_GAS = "Gas boiler/circulator, mains gas"
     UNKNOWN = "Unknown"