Abstract: A method of controlling a heating system including at least a first stage heat pump and a second stage auxiliary heater, and a control that implements the method. The control shuts off the first stage heat pump during cold outside temperatures without the need to directly sense the outside temperature. The method includes selectively turning on the first stage heat pump or the second stage auxiliary heater based upon a measure of the amount of time at least one of the stages was on verses the time neither of the stages was on. This can be implemented with a counter that increases when neither the heat pump nor the auxiliary heater is on, and that decreases when either the heat pump or the auxiliary heater is on.

Abstract: A method and device includes the use of multiple remote sensors transmitting temperature information to a thermostat, while reducing or eliminating transmission interference and providing increased user control. Remote temperature sensors of the present invention sense temperature at variable time periods and only transmit temperature information on a sensed change in temperature. Transmission of temperature information is provided on variably selected frequencies within a specified range, and may be based in part on previous temperature transmissions. A learn mode is provided that allows for recognition of each sensor by a host-controlling thermostat, including determining the proper transmission power level for each sensor. Additionally, each sensor is programmable to provide a temperature offset and each sensor may be individually weighted according to specific requirements or needs.

Abstract: A thermostat for an environmental control load that includes a temperature sensor, a timer, and a controller, and a method of controlling the thermostat that allows temporary system outages including, but not limited to, outages caused by lockouts or failure of pulsed relays to operate, to be corrected automatically, by the thermostat itself. The environmental control load may include a heating system such as a heat pump or a millivolt heating system, although the thermostat and its method of operation could also be employed with cooling systems, or heating and cooling systems. The controlled load may be one that has a "lockout" mode to prevent activation when a problem is detected, such as a reduction in gas pressure. The temperature sensor detects whether, for example, a request for heat issued by the controller has been satisfied, or alternately, if the ambient temperature has risen within some period of time, usually about two hours.