What general saving can be expected by adjusting an electric heater down by three degrees?

Adjusting the temperature setting of an electric heater down by three degrees can have a significant impact on energy consumption and cost savings. Typically, reducing the thermostat setting by 1 degree can lead to an energy savings of approximately 3% to 4% in heating costs.

When you apply this general rule to a 3-degree reduction, it compounds the savings. For example, lowering the temperature by three degrees could result in a reduction of heating demand from approximately 9% to as much as 12%. This range reflects variations due to factors such as local climate, the insulation quality of the home, and overall heating usage patterns.

Given this understanding, the choice indicating a saving of 6-12% encompasses the potential savings effectively while accounting for variations in specific circumstances. Thus, the expected overall savings by making such an adjustment aligns with the stated range, justifying the answer.