Thermodynamic Heating AC

The question is great for some industries and non-applicable for others. A general contractor, for example, will by definition employ subcontractors. Most San Diego Heating companies do not, but there are exceptions. You should always ask this question to your service providers. If they do use subcontractors, ask if they're all licensed and insured independently.

You'll always want to ask how long the company has been in business in San Diego. While this isn't a guarantee that the company will do good work, companies with longevity on their side must be doing something right. That being said, there are newer companies that do great work. If the company is under three years old, ask where the owner was employed before and for how long. If he/she has a long history of employment, it's reasonable to infer that he or she decided to go into business for themselves after so many years of experience.

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.

This is very important, since an estimate is just that. Many contractors will submit a "paper estimate", meaning they've written the estimate down on paper. The bill is the true amount owed and will almost always say "Invoice" or "Bill" at the top of the page. The bill should also list the date it was issued, the due date of payment, and a list of services rendered.

This is important mostly for larger jobs. Clearly a two man operation is going to build a home much slower than a 15 man crew. This is also a good indication of the overall size of the Heating company, if that's an area of concern for you. The reason you may want to ask about the fleet is that fleet size is a good indicator of the mobility of the company. Mobility may not sound important, but it's hard for the San Diego contractors to get to job sites if they lack appropriate vehicles.