Until you can explain the sale — then stop. The documented test: you understand the problem, why it's being solved now, what the hot button is, and how you will personalize the presentation. Past that point, more questions stop earning their place, and layering starts costing you energy, momentum, and the homeowner's patience.
The short answer
Before asking another layer, ask yourself the training's own check: do I already understand this? If yes, move on. A rep can ask forty questions and learn nothing; another can ask eight great questions, listen carefully, follow the right answers, and understand exactly how to sell the homeowner. The goal is never ask more — it is understand more.
When a homeowner hands you the complete picture in one answer — the freezing bedroom, the space heaters, the plastic on the windows, the daughter who needs it comfortable before winter — six more questions about comfort are not thoroughness. They are you not listening.
How it runs
Stop when you can explain the sale. If you can say, in their words, what the problem is, why now, what matters most, and what done-right looks like — discovery has done its job. Stop when the homeowner has clearly prioritized. They have told you what matters most; believe them. Stop when the energy drops. Watch the homeowner: curiosity reads one way, nosiness another, and the line is visible in the room before it's visible in your notes.
Two traps close the list. Don't beat a hot button to death — naming it five times drains the very emotion that made it valuable. And don't layer yourself into an objection or out of momentum: depth is a means, and the presentation is still ahead of you.
Go deeper
Spar grades your probing against the documented system, round by round. Round 1 is free. Spar before you knock.