1. Observe and protect
Write down what you're noticing, take a few photos, and gather any past service records before the first call.
2. Evaluate the house and site
A real evaluation checks duct condition, insulation, electrical capacity, and how comfort varies room to room — not just the age of the outdoor unit.
3. Define a written scope
The written scope should cover site protection, materials, permits, testing, cleanup, what's excluded, and how changes get priced.
4. Compare providers
Look past the bottom line — compare how each provider reached their number and what they're explicitly not including.
5. Inspect closeout
Before signing off, confirm test results, a clean site, paperwork, warranty terms, and what maintenance is still on you.