Furnace replacement leads: how HVAC companies spot older homes and new owners before the first freeze

Oct 3, 2026 · Heating season · For HVAC owners and comfort advisors · HVAC buyer packs

Every HVAC shop knows the pattern. The first cold night arrives, the phones light up, and for two weeks you are turning down work. Then it goes quiet. The calls you wanted, the planned replacements, mostly went to whoever got there first. Furnace replacement leads are easier to find before the rush than during it, and most of the signals are public.

This guide covers where to look, how to separate a likely replacement from a likely repair, and what to say to a homeowner who has not called anyone yet.

1. Why age is the first filter

ENERGY STAR’s repair-or-replace guidance says to consider replacing a furnace or boiler that is more than 15 years old, and a heat pump or central AC over about 10 years, especially with repeat repairs or uneven comfort (ENERGY STAR, when is it time to replace?). The Department of Energy’s contractor guide uses a similar rule of thumb: if repairs cost more than half of a replacement, replacing usually wins (DOE Building America HVAC guide).

You cannot see a furnace from the street, but you can often see the house’s age and, sometimes, the system’s:

• Year built on county assessor pages and recent listings. A 1990s house that never had a mechanical permit is a reasonable guess for an original or second-generation system.
• Listing remarks. “HVAC approx. 18 years,” “original furnace,” or “new roof and water heater” (but nothing about heating) all tell you something.
• Mechanical permit history. If the city’s permit portal shows a furnace change-out three years ago, drop the row. If it shows nothing since the house was built, keep it.

2. New owners: the best window you are probably missing

People who just bought a house have a home inspection report on their kitchen table, and many inspection reports flag the age of the heating system. They also have no existing HVAC company. That combination, a fresh flag and no loyalty, is why recent sales are worth checking.

What to look for in public data:

• Homes that sold in the last 30 to 120 days in ZIPs you serve.
• Listing photos or remarks that show an older furnace, a window unit, or no mention of HVAC updates.
• No mechanical permit filed since the sale.

You will not see the inspection report, and you should not pretend to. The note simply offers what a new owner is likely to want anyway: a system check before winter.

3. Use the weather calendar to time it

The point of a list is to reach people before the first hard cold, not after. Two free sources help:

• Your NWS forecast office’s freeze outlooks and the 7-day forecast at weather.gov.
• NOAA climate normals for the average first fall freeze at the nearest station, which tell you roughly when your season normally starts.

Work back two to three weeks from that date. That is when a “free safety check before the first freeze” note makes sense to a homeowner, and when your schedule still has room to do the visits.

4. Mark each row: repair or likely replacement

A furnace repair averages around $318 nationally, with most paying $133 to $505 (Angi), while a full system replacement is commonly discussed around $7,500 (Angi). Those are very different visits. Label every row so your schedule matches:

5. What to send

Hi, congrats on the new place on [street]. Before the first freeze (usually around [month] here), we’re offering a free furnace safety check on your block on [day]. Reply with a time if that helps. [Name, company, license, phone]

Keep it to the check. Do not promise rebates or tax credits in the first touch. Utility programs change and differ by area, and getting it wrong costs you trust. If you confirm a program applies after the visit, mention it then.

Use mail, a hanger on a street you are already working, or email to a published address. If you call, scrub numbers against the National Do Not Call Registry first.

6. A one-week plan for one ZIP

Here is an EXAMPLE schedule, not a benchmark. Adjust it to your crew.

1. Monday: pick one ZIP you already drive. Pull recent sales from the last four months and note year built and any HVAC line in the listing remarks.
2. Tuesday: check each address on the city permit portal. Drop anything with a furnace or condenser permit in the last five years. Mark the rest repair or likely replacement.
3. Wednesday: add any public neighbor posts from that ZIP about heating trouble. Answer those first, like a neighbor.
4. Thursday: send the note to the new-owner rows and leave hangers on streets where you already have a service call that day.
5. Next Thursday: one follow-up to anyone who did not reply, then stop. Log who booked a check and who booked a replacement estimate.

Twenty-five rows worked this way is a few hours, spread across a week, before the season gets loud.

7. Do not do these

• Do not tell a homeowner their furnace is unsafe before you have seen it.
• Do not quote rebate amounts you have not confirmed for their utility.
• Do not send a “system is failing” scare letter. Age is a reason to check, not a diagnosis.
• Do not wait for the first freeze to build the list. By then the phones are already ringing.
• Do not count a booked check as a sold system. Track both.

If you also pull permits for leads, the filters are in how to read permit data for roofing and HVAC leads. To compare a list with what you pay for inbound HVAC leads, see shared leads vs a researched buyer list. Our HVAC signals and an example pack are on the HVAC buyer pack page, and the $37 Starter Spark is 25 rows in one ZIP, each marked repair or likely replacement.