The General Electric WP70X20720 Zoneline Heater Assembly restores proper heating function in compatible Zoneline units by supplying controlled heat during operation. This replacement assembly is a built-in heating component installed inside the appliance cabinet, where it works with the fan and control system to warm passing air before it is circulated into the room. It operates by converting electrical energy into heat when activated by the thermostat or selected settings. Positioned within the internal heating section, it is used in packaged terminal air conditioner systems commonly found in residential and commercial spaces. By supporting steady temperature regulation, this part assists in reliable heating performance and proper indoor comfort during regular use.