Questions on older Mitsubishi compressor MXZ-4B36NA

I have a Mitsubishi MXZ-4B36NA that has been running flawlessly for the past 7 years. We live in Washington, DC so climate zone 4a. We have two zones (9,000 and… I have a Mitsubishi MXZ-4B36NA that has been running flawlessly for the past 7 years. We live in Washington, DC so climate zone 4a. We have two zones (9,000 and…Read MoreGreenBuildingAdvisor