Fault-tolerant HVAC system

摘要

A fault-tolerant HVAC system capable of continued operation in the event of a thermostat malfunction. An HVAC controller controls the operation of an HVAC unit in accordance with a temperature signal output from the thermostat and indicative of air temperature of a conditioned space proximate the thermostat. The HVAC controller detects a thermostat malfunction and, in response thereto, instead controls the operation of the HVAC unit in accordance with a temperature sensor outputting a signal indicative of return air temperature from the conditioned space.