A system faults to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit. The system transmits a signal to a remote sensor. The system determines that a return signal is not received from the remote sensor. The system obtains a temperature reading from the return air sensor. The system determines whether the temperature reading satisfies a temperature setting stored in the memory. In response to determining that the temperature reading does not satisfy the temperature setting, the system enables heating or cooling of the HVAC unit until the temperature setting is satisfied. In response to determining that the temperature reading satisfies the temperature setting, the system disables heating or cooling of the HVAC unit.