A GE heat pump system was replaced with a Rheem Heat Pump. The GE air handler with electric resistance still remains with the original Honeywell heat pump stat. All functions of the GE system worked including Emergency heat prior to replacement of the GE heat pump with the Rheem Heat Pump (UPKA-024JAZ). The installer told the customer that Emergency heat will not function any longer after the new Rheem heat pump was installed.
What is the difference in components from the GE v.s. the Rheem that now the Emergency heat will not work. Or what is the Rheem unit missing for components to make the emergency heat work?