1.Check credentials.
Do they have a business address? Someone operating out of their home is often a small company unable to provide service after the sale.

2. Ask for references. 
Former customers are an excellent source of information Also, ask to see installation photos. A contractor that is proud of their work will be more than happy to show it to you.

3. Did they size your system properly? 
What method did they use?

4. Expect an on-site evaluation of your home. 
A good contractor will take a thorough look at your home, ask questions and evaluate your overall comfort needs before making a recommendation. Beware of the dealer that simply takes information over the phone. The contractor should look professional.

5. Check local licenses. 
Contractors must have a state or county license. A state license is preferred since the testing is more stringent. Ask for proof of the license and look at their insurance forms for liability and workmen’s compensation. For your protection, a contractor should not be working in your home without both of these types of insurance.

6. Don’t be afraid to ask questions. 
Ask for details about the company’s experience and the expertise of its staff. This is particularly important if you’re also adding or changing duct work. Experience is a factor in sizing duct work and providing air balancing.

7. Get a written proposal. 
To make a fair comparison, make sure the proposal you receive are all based on the same efficiency and equipment. You’ll also want to evaluate each contractors’s personal business standards and policies. Will he remove the old equipment? What are his clean up and care policies.

8. Ask about equipment and labor warranties.
Limited warranties vary according to the manufacturer, so make sure you fully understand what you’re getting. Also don’t forget to ask about extended warranties at the time or purchase and other warranties provided by the dealer.

9. Ask about preventative maintenance service contracts. 
Many dealers offer service contracts that call for periodic maintenance of equipment, and if needed repairs. The fee for such contracts is usually well worth it in terms of obtaining optimum efficiency and performance for your system.

10. Finally, insist on a written contract.
Commit your agreement to writing and have the dealer sign it.