nickjb
Way more efficient than an electric heater.
Really? More than 100% efficient? .
It is in terms of CO2 emissions:
UK electricity generation emits 256g of CO2 per kWh and distribution losses cause the emission of a further 22g of CO2 per kWh (2019/20 conversion factors from DEFRA)
Total 278g of CO2 per kWh of electricity fed to your 100% efficient electric heater.
Burning natural gas generates 184g of CO2 per kWh net – i.e. condensing boiler(same source as above). Boiler efficiency is typically ~90% for a modern, condensing gas boiler.
Total of 184 / 0.9 = 204g of CO2 per kWh fed to your wet heating system – i.e. over 25% less than the equivalent electric heater.