Heat pump boiler

A heat pump boiler comprising:

• a compressor that is configured to compress refrigerant;
• an exterior heat exchanger that is configured to transfer heat between refrigerant and exterior air;
• an interior heat exchanger that is configured to transfer heat between refrigerant and water;
• a channel change valve that is configured to provide refrigerant compressed by the compressor to the exterior heat exchanger or the interior heat exchanger;
• a first boiler heat exchanger that is configured to heat water that has passed through the interior heat exchanger from heat generated through combustion;
• a second boiler heat exchanger that is configured to transfer heat between refrigerant and gas discharged from the first boiler heat exchanger;
• a defrosting valve that is configured to provide refrigerant to the interior heat exchanger or the second boiler heat exchanger;
• an outdoor unit that includes the compressor, the exterior heat exchanger, and the channel change valve;
• an indoor unit that includes the interior heat exchanger, the first boiler heat exchanger, and the second boiler heat exchanger;
• a first refrigerant pipe that defines a channel for refrigerant discharged from the outdoor unit and provided to the indoor unit;
• and
• a second refrigerant pipe that defines a channel for a refrigerant discharged from the indoor unit and provided to the outdoor unit,
• wherein the defrost valve provides refrigerant provided from the outdoor unit through the first refrigerant pipe to the interior heat exchanger or the second boiler heat exchanger.