1. Observe and protect
Write down what is happening and when it started, stop further damage if it is safe to do so, and gather whatever equipment history exists.
2. Evaluate the house and site
A real evaluation checks duct leakage, insulation, and electrical capacity alongside the equipment—not the equipment alone.
3. Define a written scope
Get prep, protection, materials, permits, testing, and cleanup spelled out, plus what triggers a change order if something unexpected shows up.
4. Compare providers
Compare the reasoning behind competing proposals, not simply which total is lowest.
5. Inspect closeout
Before signing off, confirm testing was done, the site was cleaned up, and you have warranty documentation.