Katy Homebuyer HVAC Due-Diligence Checklist

Document every HVAC component

Photograph the manufacturer label and model and serial numbers on the outdoor condenser or heat pump, indoor air handler or furnace, evaporator coil and thermostat or control equipment. Record apparent installation dates and note inaccessible or unreadable labels.

Collect service and repair history

Ask for maintenance invoices, repair receipts, warranty documents, replacement proposals and any recent diagnostic reports. A verbal statement such as “serviced every year” is less useful than dated documentation that identifies the equipment and work performed.

Identify the refrigerant without turning it into a verdict

R-22 is no longer produced or imported in the United States, but existing systems are not illegal. R-410A remains common, while newer equipment may use lower-global-warming-potential refrigerants such as R-32 or R-454B. Refrigerant type affects service planning; it does not by itself decide whether a system should be replaced.

Refrigerant handling and opening the system belong to properly certified professionals. See the EPA's R-22 homeowner guidance and HFC phasedown FAQ.

Compare indoor and outdoor components

Matching is more than using the same brand. Compare model numbers, nominal capacities, refrigerant and manufacturer compatibility. Ask for the applicable AHRI certificate or directory record when available. A licensed contractor can interpret whether the installed combination is appropriate.

Review condensate drainage and overflow protection

Look for visible staining, rust, algae, damaged pans, disconnected drain lines or evidence of recurring backups. Ask how the primary and secondary drainage paths work and whether a float switch or other overflow protection is installed and functional.

Inspect accessible ducts and attic conditions

Note disconnected, crushed, torn or poorly supported ducts; damaged insulation; visible gaps; restricted access; and unusually hot or humid attic conditions. Comfort problems can come from distribution and building conditions even when the equipment operates.

Interpret the temperature difference carefully

Texas inspection standards use a 15°F to 22°F supply-to-return temperature differential or an accepted alternative under specified conditions. A result in that range is one observation—not a complete diagnosis of airflow, capacity, humidity control, duct condition, refrigerant charge or remaining life.

Check the correct permit authority

A Katy mailing address may fall under the City of Katy, Harris County, Fort Bend County, Waller County or another city such as Houston or Fulshear. Search the authority that had jurisdiction when the work occurred. A missing online record is not conclusive; verify the address, date, scope and archival system directly.

Verify Texas licensing

Use the Texas Department of Licensing and Regulation license search to verify the contractor or technician information relevant to the proposed work. Confirm the name, license status and scope before authorizing service.

Resolve questions before the option period ends

Write down unresolved defects, missing records, specialist recommendations, proposed repairs and credits. Do not calculate or assume the contractual deadline from this guide. Your signed contract and advice from your real estate professional or attorney control.