STANDARD_HEATING_SYSTEMS = {
    "gas combi boiler",
    "electric storage heaters",
    "district heating",
    "gas condensing boiler",
    "oil boiler",
    "gas condensing combi",
    "air source heat pump",
    "boiler - other fuel",
    "ground source heat pump",
    "electric radiators",
    "other",
    "electric boiler",
    "unknown",
    "communal gas boiler",
    "high heat retention storage heaters",
}

HEATING_MAPPINGS = {
    "Combi - GAS": "gas combi boiler",
    "E7 Storage Heaters": "electric storage heaters",
    "District heating system": "district heating",
    "Condensing Boiler - GAS": "gas condensing boiler",
    "Boiler Oil/other": "oil boiler",
    "Condensing Combi - Gas": "gas condensing combi",
    "Air Source Source Heat Pump": "air source heat pump",
    "Biomass Boiler": "boiler - other fuel",
    "Ground Source Heat Pump": "ground source heat pump",
    "Electric Oil filled radiators": "electric radiators",
    "Solid Fuel": "other",
    "LPG Boiler": "boiler - other fuel",
    "Electric Boiler": "electric boiler",
    "No data": "unknown",
    "Boiler Communal/Commercial - GAS": "communal gas boiler",
    "Eco Electric Radiators": "electric radiators",
    "Gas fire": "other",
    "Backboiler - Solid fuel": "other",
    'combi - gas': 'gas combi boiler', 'e7 storage heaters': 'electric storage heaters',
    'district heating system': 'district heating', 'condensing boiler - gas': 'gas condensing boiler',
    'boiler oil/other': 'oil boiler', 'condensing combi - gas': 'gas condensing combi',
    'air source source heat pump': 'air source heat pump', 'biomass boiler': 'boiler - other fuel',
    'ground source heat pump': 'ground source heat pump', 'electric oil filled radiators': 'electric radiators',
    'solid fuel': 'other', 'lpg boiler': 'boiler - other fuel', 'electric boiler': 'electric boiler',
    'no data': 'unknown', 'boiler communal/commercial - gas': 'communal gas boiler',
    'eco electric radiators': 'electric radiators', 'gas fire': 'other', 'backboiler - solid fuel': 'other',
}