Understand your estimate
For a 2,000 W heater used for two hours a day at 25p per kWh, the estimate is £1 per day. Ten 50 W bulbs replaced with ten 5 W LEDs, used four hours daily at the same rate, would save an estimated £164.25 a year.
These are examples, not current tariff quotes. Use your bill and actual usage for a more useful comparison.
Heater running costs · LED savings explained · Understanding your tariff