Air pump heat pump? How many kWh of gas were you using for heating in winter before the switch? How many kWh of electric do you use now?did you have to replace

Air pump heat pump? How many kWh of gas were you using for heating in winter before the switch? How many kWh of electric do you use now?did you have to replace your radiators or add any extra insulation? I’ve got a 1962 house with an oil boiler, currently using about 10 litres a day on heating, tempted to change to an air powered heat pump