Before You Hire an HVAC Tech
A short checklist for homeowners comparing heating and cooling contractors.
Load calculations
- Ask if they will size the system with a real load calculation (Manual J or equivalent) — not a rule of thumb from square footage alone
- Confirm they will share the results in writing before you buy equipment
- If replacing ducts, ask about duct design (Manual D) so the new system is not fighting leaky or undersized ducts
Refrigerant credentials
- Ask who on the crew holds EPA Section 608 certification for refrigerant handling
- Confirm they can service your refrigerant type (including newer A2L refrigerants if that is what the equipment uses)
- Ask how they handle recovery and disposal — illegal venting is a red flag
Maintenance plans
- Get the plan in writing: what is included, how often, and what is not covered
- Ask whether the plan is tied to the company that sold the system or transferable
- Clarify response-time expectations for no-heat / no-cool emergencies
Licensing and insurance
- Verify state/local HVAC contractor license (and ask for the license number)
- Ask for proof of liability insurance and workers’ compensation
- Confirm permits: who pulls them, and who handles the final inspection
Written estimates
- Get a written estimate that lists equipment model numbers, efficiency ratings, labor, and timeline
- Ask what happens if the job uncovers extra work (change-order process)
- Compare apples to apples: same capacity, same features, same warranty length
Warranties
- Separate manufacturer equipment warranty from the contractor’s labor warranty — get both in writing
- Ask what voids the warranty (missed maintenance, DIY filters, wrong refrigerant)
- Confirm who you call first if something fails: manufacturer, contractor, or both
Must-ask questions
- Who will actually be on site — employees or subcontractors?
- How do you handle after-hours failures during the first year?
- Can you share two recent local references for similar jobs?
Red flags
- Pressure to sign today for a “one-day-only” discount
- Vague or verbal-only pricing with no model numbers
- Unwillingness to pull permits or do a load calculation
- Cash-only, no contract, or "we’ll figure out the size later"