The fan is running. Does that mean the furnace is heating?
No. Air can move while the system is not making heat. A fan can run between heating cycles. A heat pump also differs from a fuel-burning furnace. Note what the thermostat shows and whether the room gets warmer. One vent cannot tell you if the whole system works.
Compare the display with the room
If there is no gas smell, CO alarm or other hazard, read the normal thermostat screen. Note the room reading, target, heat mode and fan setting. An old service record or a label you can see safely may help identify the system. Keep covers in place.
Say whether the whole home feels cold or just one room. “Air moves but the room reading does not rise” gives a clear starting point. Do not keep raising the target to force a response.
Explain which equipment can be reached
In a managed North Naples building, the wall control and outdoor unit may need different access. If so, give the unit number and name who can arrange entry. Do not enter a locked service room or climb to a roof to read a label.
The owner, resident and manager may each have useful details. Gather the notes and service records before the visit. Do not delay leaving for a gas smell or alarm to collect them.
Ask what the repair will address
Before agreeing to parts, ask what test supports the repair. Find out which unit it concerns. A control fault, a lack of heat and poor airflow need different work. Ask how the fix would address the cold room. Check service coverage and visit options when you call.