Short answerFurnaces and central air conditioners commonly last many years with maintenance, but age, service history, and condition matter more than a single number. Inspectors check operation, age, venting, the condensate drain, filters, and ductwork, and may recommend an HVAC technician for a suspected heat exchanger crack. Replacement is a budget item unless the system fails or is unsafe.
What do inspectors check?
Operation in heating and cooling, data plates for age, flue venting, condensate drainage, filters, and visible ducts.
What are the common findings?
- Units near or past typical life.
- Dirty filters and lack of service records.
- Condensate leaks.
- Rusted or improper flue venting.
- Possible heat exchanger cracks.
- Disconnected or leaking ducts.
How serious is it?
Age alone is a budget item. A cracked heat exchanger, carbon monoxide concern, or failed system is serious.
What does it cost to fix?
| Item | Planning estimate | Source |
|---|---|---|
| Furnace replacement | $3,800 to $7,500 | W |
| AC condenser and coil | $5,500 to $9,800 | W |
| Furnace and AC together | $8,500 to $14,500 | W |
| Duct repair or sealing | $250 to $1,500 | W |
Planning estimates, not bids. Local contractors may price differently.
When is a specialist needed?
Heat exchanger questions, carbon monoxide concerns, or a system that does not heat or cool.
If you are selling
Fix cheap safety items before listing, get a quote on anything big, and disclose what you know. What to fix before listing. A recent service record helps.
If you are buying
Sort the finding into normal for age, negotiate, specialist, or walk away. What to ask the seller to fix.
Frequently asked questions
Should I ask the seller to replace an old furnace?
Usually not if it works safely. Budget for it.
Do appraisers check heating?
Government loans require an adequate heat source.
Keep reading
Want to know what a buyer's inspector may find before they do?
Book a free pre listing condition walk. I walk the house with you, point out what inspectors and FHA, VA, and USDA appraisers tend to flag, and give you planning ranges so you can decide what to fix, credit, price in, or disclose.
Book a condition walkOr call or text (812) 525-5489, or email john@yourpropertynegotiator.com.
The condition walk is a REALTOR® and contractor evaluation, not a home inspection, and it does not replace one. If you have already signed a listing agreement with another agent, please take these questions to your agent.
Looking at a house and not sure what you are getting into?
Ask for a free Before You Offer review. Send me the listing. I look over the photos, the seller's disclosure, and recent sales, then flag likely condition issues and planning cost ranges before you write an offer.
Request a Before You Offer reviewOr call or text (812) 525-5489, or email john@yourpropertynegotiator.com.
The Before You Offer review is a REALTOR® and contractor review of the listing, not a home inspection. It is for buyers who are not already working with an agent. If you have an agent, please bring these questions to your agent.
Sources
- Wardmark Property Operations pricing, June to September 2026
Written by John Long, REALTOR®, 1 Percent Lists Indiana Real Estate. Working contractor who has priced hundreds of home inspection repair requests. Former labor relations negotiator for a major manufacturer and U.S. Coast Guard veteran.
John Long, REALTOR® · 1 Percent Lists Indiana Real Estate · (812) 525-5489 · yourpropertynegotiator.com
This page is general information, not a substitute for a professional home inspection, and not legal, tax, insurance, or lending advice. Ask a real estate attorney about contracts and disclosure, a CPA about taxes, your lender about loan rules, and a licensed inspector or tradesperson about your house. Nothing here guarantees a sale price, net proceeds, repair cost, payment, timeline, appraisal, inspection result, or loan approval. Cost figures are planning estimates, not bids. I own Wardmark Property Operations LLC, a contracting company. You are always free to use any contractor you choose.