A system for killing pests in an affected area of a structure comprises a heat pump unit placed within an affected area and a thermostatic control. The heat pump unit is configured to receive a flow of water from a faucet, and generate heated air by transferring heat from the flow of water, the heated air being emitted into the affected area in order to raise the temperature of the affected area to a target temperature greater than 120 degrees Fahrenheit. The thermostatic control is configured to monitor a temperature of a flow of water as it is received by the heat pump, monitor a temperature of air, and automatically cease operation of the heat pump when the temperature of the flow of water is above a predefined limit.