Short answer
Verify the contractor's license with your state or city, ask whether they'll do a load calculation and pull the permit, and compare written quotes line by line. Be wary of quotes that size equipment by square footage alone or skip the permit.
Questions to ask
Good contractors answer these easily.
- What's your license number, and who issued it?
- Are you insured for liability and workers' comp?
- Will you perform a Manual J load calculation?
- Will you pull the permit?
- How will you verify the refrigerant charge?
- What's the equipment and labor warranty?
- Do you check and seal the ductwork?
- Who does the install: your employees or subcontractors?
Red flags
Watch for these.
- Sizing based only on the old unit or square footage
- Pressure to sign the same day
- No written quote
- Skipping the permit
How licensing works
HVAC licensing varies by state. Some states, such as Texas, Florida and California, license statewide; others, like Colorado and Missouri, leave it to cities and counties. Your state page on this site explains where to check.
Common questions
How many quotes should I get?
Two or three for a replacement. For a repair, one qualified diagnosis is usually enough.
How does HVAC Matchline choose contractors?
We route calls to independent HVAC contractors who buy service requests in your ZIP code. Always verify the license of the contractor you hire.
This guide is general information, not a diagnosis. HVAC systems vary; a licensed technician should inspect yours before repairs.