Heat delivered is not electricity consumed
A resistance heater converts electricity into heat at the point of use. A heat pump moves heat and can deliver more heat energy than its electrical input. Its coefficient of performance changes with outdoor conditions, equipment, defrost behaviour, and supply temperature.
Compare the same comfort requirement
Decision formulaHeat-pump electricity ≈ required heat ÷ seasonal coefficient of performance
Do not compare a small room heater with a whole-home system without matching the area, temperature, schedule, and delivered heat. Include backup resistance heat where the system uses it.
Operating savings are not the full decision
Installation, maintenance, building fabric, equipment life, cooling value, local climate, and tariff structure can dominate payback. Use the running-cost comparison as one layer of a complete ownership decision.
Run your own scenario