Confirm what equipment is actually there
Ask for a readable model and serial number, fuel type, installation record if available, and prior service or repair invoices. Have the inspector or technician obtain information behind panels. The serial number may establish manufacture information; the invoice may establish when the furnace was installed. Those are separate records.
Find out whether this furnace also provides the indoor blower for AC. Identify which areas it serves and whether another system heats part of the home. A purchase decision is easier when the equipment list reflects the whole house.
What should the assessment answer?
Ask the technician to explain the observed condition, operating checks, any safety concern, and whether further investigation is needed. Fuel-fired equipment and venting should be professionally inspected; a running furnace alone does not establish safe operation. Red Cross CO prevention guidance.
Request a clear distinction between a verified defect, a maintenance need, a limitation of the visit, and future planning. For example, “manufactured in 1988” records age. It does not prove a cracked heat exchanger. Equally, “it turned on” does not answer the heat-exchanger question.
Ask whether any needed approved parts remain available, whether the existing controls and venting need attention, and which findings affect continued use. Ask the homeowner for repair history, but preserve the difference between their recollection and a documented finding.
Budget for a real alternative
Frequent repairs, comfort problems, and operating costs are reasons to consider replacement. ENERGY STAR lists those alongside age in its replacement guidance. None supplies an exact remaining-life forecast for this furnace. ENERGY STAR replacement considerations.
If replacement is a likely planning need, obtain a home-specific written estimate. Have it include the proposed equipment, sizing basis, necessary related work, exclusions, permits where applicable, and other-trade responsibilities. Do not assume a new cabinet will fit the old installation without changes.
Keep the purchase decision and service decision clear
A technical report helps you understand the equipment. Your real-estate professionals help apply it to inspection contingencies, negotiations, and closing decisions. Neither should promise how many winters the furnace will last.
The next step is to obtain the equipment record and a qualified condition report before your decision deadline. Use confirmed findings and a complete replacement estimate to plan, rather than choosing between “old means unsafe” and “working means fine.”