diff --git a/domain/epc/property_overlays/main_heating_system_overlay.py b/domain/epc/property_overlays/main_heating_system_overlay.py
index f99a24f5c..295a7e18f 100644
--- a/domain/epc/property_overlays/main_heating_system_overlay.py
+++ b/domain/epc/property_overlays/main_heating_system_overlay.py
@@ -130,6 +130,13 @@ _ELECTRIC_ROOM_HEATER_CODES = frozenset(range(691, 702))
 # unambiguously electric, so they drag electricity like the electric room heaters
 # (ADR-0045, closing the prior no-fuel gap on 191/192).
 _ELECTRIC_BOILER_CODES = frozenset({191, 192})
+# SAP Table 4a "boiler system" category — codes 191/192 are wet electric
+# boilers, same category the gas-boiler overlay stamps. Forced so an
+# electric-boiler override never keeps the replaced system's category: on
+# portfolio 796 an inherited 6 (community) or 4 (heat pump) suppressed the
+# HHRSH pathway, and an inherited 7 (storage) made the Table 12a resolver bill
+# direct-acting heat wholly at the off-peak low rate (ADR-0052, #1444).
+_ELECTRIC_BOILER_CATEGORY = 2
 # Electric underfloor — SAP Table 4a 421/422 (off-peak) and 424 (screed) — also
 # unambiguously electric (ADR-0046).
 _ELECTRIC_UNDERFLOOR_CODES = frozenset({421, 422, 424})
@@ -304,6 +311,8 @@ def _category_for(code: int) -> Optional[int]:
         return _STORAGE_HEATER_CATEGORY
     if code in _ELECTRIC_UNDERFLOOR_CODES:
         return _UNDERFLOOR_CATEGORY
+    if code in _ELECTRIC_BOILER_CODES:
+        return _ELECTRIC_BOILER_CATEGORY
     if code in _HEAT_PUMP_CODES:
         return _HEAT_PUMP_CATEGORY
     if code in _HEAT_NETWORK_CODES: