Why this list matters
HVAC is one of the few home-improvement categories where the worst install and the best install can look identical for the first six months. Performance differences show up only when the system actually has to work hard — meaning January in Duluth. By then, fixing a bad install means tearing things out. Asking the right questions before you sign protects you.
The 10 questions
1. Are you licensed in Minnesota and what is your license number? Minnesota HVAC contractors must be licensed and bonded. Verify the number against the MN Department of Labor and Industry. Our number is MB715020.
2. Do you carry workers' comp and liability insurance? Ask for a certificate of insurance. If a worker is injured on your property and the contractor doesn't carry comp, you can be liable.
3. Will you run a Manual J before sizing the equipment? The right answer is yes — every project. If they say "we'll size it to what was there," walk away.
4. What is your design temperature for this address? A real designer knows the design temp for Duluth (-19 °F), Cloquet (-23 °F), and Carlton (-24 °F). A vague answer means they're using generic state averages.
5. How do you select equipment — brand-driven or load-driven? The right answer is load-driven. Some contractors are locked into one brand; that's fine if the brand fits, but it shouldn't drive every project.
6. What is the equipment warranty AND what is your labor warranty? Manufacturer warranties cover parts. Labor is on the contractor. Two-year labor is industry standard for installs; we offer it on every job.
7. How do you handle change orders mid-project? The right answer is written, signed, and priced upfront. Verbal "we'll figure it out" usually leads to disputes.
8. Who pulls the permit? The contractor should — every time. Homeowner-pulled permits often mean the contractor isn't licensed in your jurisdiction.
9. Can I see three references for similar projects? Yes is the right answer. We provide references on request.
10. What's your maintenance plan after the install? Annual service is critical for efficiency-rated warranties. Make sure there's a clear path to ongoing service.
What our answers look like
For the record: MN Licensed #MB715020. Fully insured. Manual J on every project. -19 °F design temp for Duluth (Cloquet, Carlton, Two Harbors each have their own). Load-driven equipment selection across multiple brands. Two-year labor warranty on every install. Written change orders. We pull every permit. References available. Annual maintenance plans available for every system we install.