Desert Diamond Mechanical is the best Heating and A/C company I have ever delt with. Calls into the office are always answered right away by a smiling voice and returned calls happen very quickly. I was so impressed with their level of service that I purchased a service contract with them that gives me service with any breakdown within 24hours. This summer my A/C unit went out, and in the past when the OTHER GUYS were telling me that I would have to wait days without A/C for someone to come out to inspect my unit because it was summer and they were busy, Desert Diamond Mechanical was at my home within 2 hours and had my system up and running....they even took care of dealing with the warranty on my A/C unit for me and the repair cost me nothing. I have tried other service companies, but these guys give real meaning to the words SERVICE and CUSTOMER SERVICE. I am also a Realtor in Phoenix AZ and I this company for my own personal residence as well as refer them to all of my clients.