Grounding
Tying an answer to a source you can go and check. Closely related to retrieval, and not the same thing.
Checkable · the test is below
What it means
Retrieval is fetching material. Grounding is the answer actually resting on that material rather than on the model's own priors. An engine can retrieve a page and still write something the page does not say.
Why it matters for an HVAC company
Ungrounded claims about your business are a real operational risk. An answer inventing your hours, your service area or your licence status is not a marketing problem, it is a customer arriving at a closed door.
What would settle it
Open the cited source and check whether it says what the answer claims. That is the entire test, it costs two minutes, and almost nobody does it.
A worked example
An engine names a contractor and states they offer 24-hour emergency service. The cited source is a directory listing that says nothing about hours. The answer is retrieved but not grounded, and the contractor is now fielding 2am calls they do not take.