Whether you are buying a brand-new build in Prosper or Little Elm or an established resale home in Plano or McKinney, the HVAC system deserves its own look. New construction tends to hide cut corners—undersized returns, low charge, kinked attic duct. Older homes hide age and patch repairs. Both can cost you thousands after closing if you skip the check.
Work through the checklist below before you sign. If you find an aging or undersized system, get a replacement quote while you still have negotiating room, and set up a maintenance plan the season you move in to protect whatever you inherit.
Pre-Purchase Inspection Checklist
Find the data plate and read the real age
The manufacture date is stamped on the condenser data plate (often coded in the serial number). A 14-year-old system in a North Texas climate is near the end of its life—our summers run compressors 6+ months a year, so equipment ages faster here than in milder states. Plan for a $9,000-$16,000 replacement.
Ask for two seasons of maintenance records
No paper trail usually means no spring coil cleaning, no condensate flushes, and no capacitor checks. Neglected systems fail early. A seller who kept records is a seller who maintained the equipment.
Confirm the refrigerant type
R-410A is the standard for systems installed in the last decade; newer 2025+ installs use R-454B. An older R-22 system is a red flag—R-22 is phased out and topping off a leak can cost $100+ per pound, if a tech will even do it. An R-22 unit signals an imminent full replacement.
Verify the indoor and outdoor units are a matched set
A new condenser bolted to a 15-year-old coil (or vice versa) loses efficiency, voids warranties, and often hides a band-aid repair. Mismatched systems rarely deliver their rated SEER2.
Inspect the ductwork and attic insulation
In North Texas attics that hit 130°F+ in summer, leaky ducts bleed 20-30% of your cooled air into the attic. Look for crushed flex duct, disconnected runs, and missing insulation—cheap to seal now, expensive to ignore.
Check for permits on any HVAC work
Texas requires a licensed contractor and permit for system replacements. Unpermitted "handyman" installs may be undersized, improperly charged, or out of code—and the liability becomes yours at closing.
Find and confirm the warranty status
Manufacturer parts warranties (often 10 years) frequently transfer to a new owner if registered and transferred within a set window—usually 30-90 days. That can be thousands of dollars of coverage. Get the model and serial numbers and check before closing.
Red Flags to Watch For
- Equipment over 14 years old (North Texas heat shortens lifespan)
- No maintenance records available
- R-22 refrigerant system (phased out, costly to service)
- Rust on the coil, drain pan, or refrigerant lines
- Mismatched indoor coil and outdoor condenser
- Single undersized system cooling a large two-story home
- Builder-grade single-stage unit in a 4,000+ sq ft house
- Water stains under the air handler (chronic drain or coil leaks)
Request These Documents
- • Installation date and original invoice
- • Maintenance records (last 2-3 years)
- • Warranty information and transfer requirements
- • Permit documentation for any HVAC work
- • Recent utility bills (to estimate costs)
Consider a Dedicated HVAC Inspection
Standard home inspections check basic function but not efficiency or remaining lifespan. A dedicated HVAC inspection ($150-$300) includes refrigerant pressure testing, amperage readings, and estimated remaining useful life — especially valuable for homes with equipment over 8 years old.
If replacement is needed, review our HVAC buying guide and learn about available rebates and tax credits.
New Build vs. Resale: What to Watch
North Texas spans fast-growing new construction and established neighborhoods. The HVAC risks are different for each.
New Construction (Prosper, Little Elm, Frisco, Celina-area builds)
- Builders install the cheapest code-compliant equipment—usually a single-stage unit sized to the minimum. Comfort in a hot upstairs room often suffers.
- Common new-build defects: undersized returns, kinked flex duct in the attic, low refrigerant charge, and registers that whistle.
- Use the builder's warranty window. Document any room that runs warm and report it in writing before the warranty expires—two-story homes especially.
- Even on a brand-new system, get an independent airflow and charge check. Builder crews move fast and "good enough" is the standard.
Resale / Older Stock (established Plano, McKinney, Allen, Addison)
- Focus on remaining lifespan. A 12-14 year old system that "works" at inspection may not survive the first August.
- Aging ductwork in older homes decays—sealing it can recover meaningful efficiency without touching the equipment.
- Watch for R-22 systems and prior patch repairs. Two service stickers on the unit can tell a story the disclosure does not.
- Negotiate. A documented near-end-of-life system is legitimate leverage for a price reduction or a seller credit toward replacement.
What to Budget (2026 North Texas)
Use these ranges to set aside the right cushion before you take ownership.
| Item | Typical Cost | Notes |
|---|---|---|
| Pre-purchase HVAC inspection | $150-$300 | Refrigerant pressures, amp draw, remaining-life estimate |
| Minor repairs (capacitor, contactor, drain) | $150-$400 | Common first-year items on resale systems |
| Duct sealing / return correction | $500-$2,500 | Recovers efficiency lost to attic heat gain |
| Full system replacement (single system) | $8,000-$16,000 | Sized with a proper Manual J load calc |
| Two-system replacement (larger 2-story home) | $16,000-$28,000 | Common in 3,500+ sq ft North Texas homes |
Replacement pricing depends on system size, efficiency (SEER2), and ductwork condition—a proper Manual J load calculation should drive the sizing, not a like-for-like swap.
Frequently Asked Questions
How old is too old for an HVAC system when buying a North Texas home?
A system over 14 years old should be treated as near end-of-life here. North Texas runs air conditioning roughly six months a year, often in 100°F+ heat, so compressors and coils wear faster than in cooler climates. A well-maintained system can reach 15-18 years, but neglected equipment often fails by 12-13. If the unit is past 14 and lacks maintenance records, budget for replacement ($8,000-$16,000) and use it as a negotiating point before closing.
Does a standard home inspection cover the AC and furnace adequately?
Not really. A general home inspector confirms the system turns on and produces cold or warm air, but does not test refrigerant pressure, measure amp draw, check the actual charge, or estimate remaining lifespan. For a major purchase, a dedicated HVAC inspection ($150-$300) is worth it—especially on systems over 8 years old or when you have no maintenance records. It tells you whether you are buying a few good years or a replacement bill.
I'm buying a brand-new build in Prosper—do I still need an HVAC check?
Yes. Builders install the least-expensive code-compliant equipment, and crews work fast. The most common new-construction issues we see are undersized returns, kinked or crushed flex duct in the attic, low refrigerant charge, and a single-stage unit that struggles to keep a two-story home even upstairs. An independent airflow and charge check catches these while the builder warranty still covers the fix. Report any warm room in writing before that window closes.
Is an R-22 system a dealbreaker?
It is a serious red flag, not always a dealbreaker—but price it in. R-22 refrigerant was phased out of production, so any leak repair on an R-22 system is expensive (often $100+ per pound) and getting harder to source. An R-22 unit is also old by definition, since R-410A became standard over a decade ago. Treat it as a replacement coming soon and negotiate accordingly. We can quote a modern R-410A or R-454B system before you close.
Will the manufacturer warranty transfer to me as the new owner?
Often yes, but only if it is handled correctly. Many manufacturers allow the original 10-year parts warranty to transfer to a second owner if you register the transfer within a set window—usually 30 to 90 days after closing—sometimes for a small fee. Get the model and serial numbers off the data plate, confirm the registration status, and complete the transfer promptly. Miss the window and the coverage can drop to a shorter default term.
Should I budget for one system or two on a larger two-story home?
Many North Texas homes over about 3,000 square feet use two complete systems—one per floor (zone)—because a single unit cannot evenly cool a tall, sun-exposed house in our summers. Confirm whether the home has one system straining to do the whole job or two properly sized systems. A single undersized unit on a big two-story home means hot upstairs bedrooms and a likely upgrade. Budget $16,000-$28,000 if both systems are aging.