What are they? Is it just price? Is it value for your money, warranties, guarantees? Or something else?
Mine would be the way they present themselves in the 1st meeting, on the phone and do they keep their word. Where they on time? If they had to reschedule did they call within a descent time frame? Where they friendly? Did they give you a sense of peace and calmness or did you feel on edge and nervous? Ask questions about how they started doing what they do, why they continue, do they sub out all the work or do they employee ppl and do the work themselves? Price maybe the big issue to some but always look at like this if you get 3 bids and they are close from $15k $13k and then $9k the $9k is probably not quality work and seeing that the 15 & 13 isn’t much difference between which one made you feel more comfortable? Always remember… when picking your contractor you are in a sense adding a new member to your family (depending how big/small your project is). They will be in and out of your home, getting to know you and your family. Also warranties and guaranties ALWAYS get them in writing along with the scope of work and any and all change orders.
Make sure the contractor licensed, bonded, & has liability insurance. You can go to www.cslb.ca.gov
to check license and bond status. Ask for proof of liability insurance. If they are pushing to get you to sign a contract on the spot, take a step back and tell them you will consider the proposal. If it’s an Air conditioning contractor and they ask for money upfront, make sure they are reputable and are who they say they are. If they ask, it should never be more then 10% of the total job price. Google the company and look for reviews on other websites.
Lastly, for Air Conditioning & Heating replacement make sure they pull a permit! You can ask for a copy of the permit application. This is important so that you know the job is done correctly, and that your system is up to title 24 compliance.