1. Observe and protect
Note what's happening and when, prevent further damage if it's safe to do so, and gather whatever equipment history you have on hand.
2. Evaluate the house and site
A real evaluation checks duct leakage, humidity control, and electrical capacity along with the equipment—not the equipment in isolation.
3. Define a written scope
Get prep, protection, materials, permits, testing, and cleanup spelled out, along with what triggers a change order.
4. Compare providers
Compare the reasoning behind each competing proposal, not simply the bottom-line number.
5. Inspect closeout
Before signing off, confirm testing was completed, the site was cleaned up, and warranty documentation was provided.