Patent ID: 8560127

Claim:
A programmable thermostat configured to control one or more pieces of HVAC equipment in accordance with a programmable schedule, the HVAC equipment capable of modifying a temperature of an inside space with at least a primary stage and an auxiliary stage, the programmable thermostat comprising: a memory for storing operating parameters of the programmable thermostat, including one or more droop values; a user interface configured to accept modification of one or more operating parameters; and a controller coupled to the memory and the user interface, the controller programmed to activate the HVAC equipment to attempt to control the temperature of the inside space under one or more of at least three conditions, including a steady state condition, a programmed recovery condition, and a manual setpoint change condition; wherein: the controller is programmed to attempt to control the temperature of the inside space with the primary stage of the HVAC equipment; and for one or more of the programmed recovery condition and the manual setpoint change condition, the controller is programmed to: determine a temperature ramp based, at least in part, on one or more of the droop values stored in the memory; and activate the auxiliary stage if the temperature of the inside space drops below the temperature ramp.