Common Heating Findings and What They Cost
Long Island's housing stock is old, and so is a lot of its heating: cast-iron oil boilers, steam systems, and furnaces that have been through a few owners. These are the findings that show up most often:
| Finding | What It Means | Typical Cost | Priority |
|---|---|---|---|
| Cracked heat exchanger (furnace) | Possible CO leak, so don't run it | $4,500–$9,000 (new furnace) | Safety |
| CO detected / backdrafting / bad venting | Exhaust not leaving the house properly | $200–$2,500 (repair to chimney liner) | Safety |
| Boiler leaking or heavily corroded | Section or tank failure is common on old cast iron | $5,500–$14,000 (replacement) | High |
| Missing or failed low water cutoff (steam) | Required safety control isn't protecting the boiler | $350–$900 | Safety |
| Unlined or deteriorated chimney | Common on oil-to-gas swaps done without a liner | $800–$2,500 (liner) | High |
| Oil tank: buried, or basement tank with weeping | Leak risk, insurance and disclosure issue | $300–$5,000+ (test, removal, abandonment) | High |
| Suspected asbestos on boiler or pipes | Needs testing; removal by a licensed contractor | Quoted by abatement contractor | Medium |
| Dirty burner, soot, overdue service | Usually a tune-up, not a defect | $150–$350 | Low |
| System 'beyond expected life' | Age only, no defect stated | $0 now, a budget item | Negotiation |
How the Heating Issue Gets Resolved
Seller repairs before closing
Best for safety items. Insist on a permit where one is required, an invoice, and a final inspection or test result, not just "it was fixed."
Credit at closing
The buyer picks the contractor and equipment. Lenders cap seller concessions, so a large credit may not fit.
Price reduction
Works when the credit is too large for the lender, and keeps the buyer's financing clean.
Escrow holdback
Some lenders and attorneys allow funds to be held for work done after closing. Ask early; not every lender permits it.
If You're the Buyer
- • Send the contractor the heating section of the report with photos so the visit targets the real findings.
- • Ask for a combustion test and carbon monoxide readings on paper. Numbers carry weight in a negotiation.
- • Get the repair-vs-replace answer and both prices. A $700 fix and a $12,000 replacement are very different asks.
- • Ask whether the existing system was installed with permits. On Long Island, an open or missing permit for a boiler swap can surface in the municipal search and delay closing.
- • If there's an oil tank, find out whether it's buried and whether it's been tested. Our oil to gas guide covers removal costs.
If You're the Seller
The cheapest heating problem is the one you find before the buyer's inspector does. A tune-up and safety check before listing ($150–$350) catches the small things, like a dirty burner, a weak low water cutoff, or missing CO detectors, that otherwise turn into a long line item on someone else's report.
Since March 20, 2024, New York sellers can no longer hand over a $500 credit in place of the Property Condition Disclosure Statement. The form is now mandatory, and it covers the home's systems and fuel storage tanks. Knowing the true condition of your boiler or furnace before you fill it out protects you as well as the buyer.
Repair or Replace?
The rule of thumb we use: if a repair costs more than about half of a replacement and the system is past 15–20 years (furnace) or 25–30 years (cast-iron boiler), replacement usually wins. See our boiler cost guide and furnace cost guide for current Long Island pricing. If the house has steam heat, read our steam boiler guide. Steam has its own rules, and its own common inspection flags.