If the outdoor heat pump unit needs replacing, can we re-use the old indoor unit?
All manufacturers require that their equipment be installed as a “matched” system. In fact, many manufacturers state in their literature that they will void the warranty if an old indoor unit is used. A new 12 SEER heat pump outdoor unit used with a 15 year old indoor unit will have an actual operating SEER of approximately 8 or 9. So, you will loose efficiency and possibly loose warranty by mismatching a system.
