Which term describes the difference between the heating cycle's turn-on and turn-off temperatures in a thermostat?

Which term describes the difference between the heating cycle's turn-on and turn-off temperatures in a thermostat?

• A. Delta-T
• B. Differential
• C. Setpoint
• D. Hysteresis

Answer: (B)

The main idea is the width of the temperature band the thermostat uses to switch heating on and off. This band is called the differential. It defines how far the temperature must rise above the setpoint to turn the heat off and how far it must drop below to turn it on again, preventing short cycling and keeping the system stable. The setpoint is simply the target temperature, not the width of the switching band. Delta-T is a more general temperature difference used in other contexts, and hysteresis describes a broader history-dependent response; in thermostat controls, the specific term for this turn-on/turn-off range is the differential.

The main idea is the width of the temperature band the thermostat uses to switch heating on and off. This band is called the differential. It defines how far the temperature must rise above the setpoint to turn the heat off and how far it must drop below to turn it on again, preventing short cycling and keeping the system stable. The setpoint is simply the target temperature, not the width of the switching band. Delta-T is a more general temperature difference used in other contexts, and hysteresis describes a broader history-dependent response; in thermostat controls, the specific term for this turn-on/turn-off range is the differential.