A heat pump water heater appliance includes a tank that defines an interior volume. A drain pan is positioned below an evaporator of a sealed system. A liquid monitoring sensor has a voltage divider with a pair of probes. The probes of the pair of probes extend into the drain pan. A related method for operating a heat pump water heater appliance is also provided.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

Embodiments of the invention provide a heater including a housing, a first tankless heater, a second tankless heater, a first and second flow directing elements, the first flow directing element in communication with the first tankless heater and the second flow directing element and the second flow directing element in communication with the second tankless heater, and a controller in communication with the first and second tankless heaters and the first and second flow directing elements, the controller configured to control the first and second flow directing elements to control flow to one or both of the first and second tankless heaters.

Embodiments of the invention provide a heater including a housing, a first tankless heater, a second tankless heater, a first and second flow directing elements, the first flow directing element in communication with the first tankless heater and the second flow directing element and the second flow directing element in communication with the second tankless heater, and a controller in communication with the first and second tankless heaters and the first and second flow directing elements, the controller configured to control the first and second flow directing elements to control flow to one or both of the first and second tankless heaters.

A heating system includes a heat pump that provides heat to a major fluid circuit and a minor fluid circuit for performing different heating operations. The system includes a power source having a variable cost and a controller configured to regulate flow of the major and minor fluid circuits to perform the heating operations. The controller is configured to receive information regarding the variable cost of the power source and distribute flow between the major and minor fluid circuits to perform the heating operations to minimize the electricity cost. The combined enhanced demand regulation and enhanced output regulation amplifies the total heat output and power consumption while permitting greater use of a power source of varying cost (e.g. PV)thereby minimizing overall daily operating cost.

A heating system includes a heat pump that provides heat to a major fluid circuit and a minor fluid circuit for performing different heating operations. The system includes a power source having a variable cost and a controller configured to regulate flow of the major and minor fluid circuits to perform the heating operations. The controller is configured to receive information regarding the variable cost of the power source and distribute flow between the major and minor fluid circuits to perform the heating operations to minimize the electricity cost. The combined enhanced demand regulation and enhanced output regulation amplifies the total heat output and power consumption while permitting greater use of a power source of varying cost (e.g. PV)thereby minimizing overall daily operating cost.

A system for space heating or cooling a heated space includes a heat pump including a refrigeration circuit for transferring heat between a heat source and a heat load for heating and cooling operations. A controller controls the heat pump to perform the heating and cooling operations. A user interface receives user inputs, wherein the user inputs include an indication of discomfort based on temperature. The controller creates a profile for a minimum comfortable temperature level and a maximum comfortable temperature level, and the controller controls the heat pump to perform the heating and cooling operations in accordance with the profiles for the minimum and maximum comfortable temperature levels. The controller may generate an optimized heat demand plan in accordance with predictions of outdoor and indoor temperature, cost, and demand. The plan is optimized to cost-effectively maintain the temperature of the heated space within the comfortable temperature range defined by the profiles.

A system for space heating or cooling a heated space includes a heat pump including a refrigeration circuit for transferring heat between a heat source and a heat load for heating and cooling operations. A controller controls the heat pump to perform the heating and cooling operations. A user interface receives user inputs, wherein the user inputs include an indication of discomfort based on temperature. The controller creates a profile for a minimum comfortable temperature level and a maximum comfortable temperature level, and the controller controls the heat pump to perform the heating and cooling operations in accordance with the profiles for the minimum and maximum comfortable temperature levels. The controller may generate an optimized heat demand plan in accordance with predictions of outdoor and indoor temperature, cost, and demand. The plan is optimized to cost-effectively maintain the temperature of the heated space within the comfortable temperature range defined by the profiles.

Embodiments include systems and methods for heating water and cooling air simultaneously, as well as other simultaneous heating and cooling operations. An example variable refrigerant flow conditioning system includes an outdoor unit having a compressor, a condenser coil, and a fan, a water heater coupled to the outdoor unit, a first air conditioning unit coupled to the outdoor unit, and a controller. The controller may be configured to determine that a cooling mode is active during a first time interval, cause vapor refrigerant to be directed from the outdoor unit to the water heater and liquid refrigerant to be directed from the outdoor unit to the first air conditioning unit, determine that an air heating mode is active during a second time interval, and cause the vapor refrigerant to be directed from the outdoor unit to both the water heater and the first air conditioning unit.