Colonial Plumbing & Heating Co

This really only matters if you have a preference, but it is good to ask. If you have a strong ideological belief about unions or nonunions, it's perfectly acceptable to make a decision based on the preference.

Many jobs in Virginia will require municipal permits in order to be approved by the town's inspector. It's always good to ask who will be responsible for pulling those permits, and if you'll be expected to do it. You'll almost never be told to pull your own, but knowing that Colonial Heights Cooling permits are required makes you appear to be a well informed customer.

These first two questions should only relate to services or good purchased directly from the service provider. Many products carry their own warranties, like roofing shingles or siding. It's useful to know what these warranties cover as well as how long they last. The "warranty agent" question is important, because often warranty agents work with the manufacturer to get you repairs under warranty at a much lower price.

This will be answered when you ask if all employees are licensed. The only way to obtain a legitimate tradesman's license is to be a legal or naturalized citizen of the US. The company may employ people in positions that don't require a license, however, so it's wise to inquire.