From E.ON: “Heatwise tariffs were offered by E.ON to customers in the East Midlands region. Like Economy 7 or Economy 10 energy plan, the Heatwise plan was designed to take advantage of cheaper electricity offered at certain times of the day. Heatwise meters work in conjunction with a storage heater in electricity-only homes. They switch on late at night and early in the morning, when demand for electricity is low.”
“Heatwise meters therefore require you to have a storage heater in your home.”
“The Heatwise plan was renamed by E.ON on the 18 January 2013, and is now known as the E.ON EnergyPlan. E.ON says that the name change in no way has changed the nature of the plan, but the structure of the tiered-rate system has changed the way your usage is calculated.”
If you’re with E.ON and live in the East Midlands, and you have two different supply numbers on your bill, you possibly had HeatWise (aka EnergyPlan). You’ll probably be paying two standing charges.
Hope that helps!