So we have what looks to be a Trane XV80 gas forced air furnace, 2002 model year? Serial # 2391TPM1G.
On the back of the furnace there is an “add on heat pump”?
Then the condenser unit outside, is not really a condenser but a heat pump unit? Dated 1989.
From what I could tell, when I called for heat at the thermostat the heat pump first kicked in, because the outside “condenser” fan kicked on. After a long wait, the gas furnace finally kicked on. So in response to your question Bob, my guess is the heat pump is the primary heat source. As a backup or secondary source the gas forced air furnace kicks on…which around here is likely more often than the heat pump.
That’s my buest educated guess. Again, since this is the first one I have ever come accross i was hoping for some more input from others. For sure the outside unit, at 22 years of age is likely at or near the end of its useful lifespan.