HVAC checklists

Before you call: filter condition, thermostat mode and batteries, breaker, furnace power switch, outdoor disconnect, blocked vents, condensate drain. Note exactly what the system does and when — "blows warm air after about ten minutes" is far more useful to a technician than "it's broken."

Vetting a contractor: state license verified with the licensing board, EPA Section 608 certification for refrigerant work as required federally, general liability and workers' comp insurance, references from jobs in your area, and a written proposal rather than a verbal number.

Reviewing a replacement quote: equipment model numbers, AHRI matched-system reference, whether a Manual J load calculation was performed, duct work included or excluded, electrical work, thermostat, permit responsibility, old-equipment removal, total price, payment schedule, parts warranty term and labor warranty term.

How to choose

Insist the load calculation appears on the quote

ACCA Manual J, S and D are the standard methods and are referenced in codes nationwide. If none is mentioned, ask why.

Check that all three bids include the same duct scope

Duct work is the most common reason bids differ by thousands. HVAC Project Cost puts repairs at $500 to $1,500 and full replacement at $2,000 to $5,000.

Verify insurance, not just license

General liability and workers' comp. Ask for certificates sent directly from the insurer where possible.

Never accept a verbal price

Everything on paper, signed, with a clear payment schedule tied to milestones.

Keep a records folder

Permit, inspection sign-off, model and serial numbers, warranty registration confirmation, and every maintenance invoice.