A water-only community scheme (water_heating_code 950/951/952) is served
by its own heat network, independent of the space main. _water_heating_fuel_code
now resolves the network's SAP Table 12 community fuel (e.g. 41 = heat from
electric heat pump @ 4.24 p/kWh, COP already priced into the row) instead of
defaulting to the space main's fuel. For a direct-electric main this had
mis-billed communal heat-pump DHW at the 13.19p standard-electric rate.
Dovestone Apt 4 (cert 9556-3047-3304-5355-1200): hot-water cost £353 → £113,
SAP 67 → 80.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DX8oAGsGkBHq3U4dsxYRzz
20268a4a6d