I was having my regular 6 month checkup on my system. The first tech just seemed to be done too quickly and he never even looked into the area where the filters are and I know was checked previously. I just put that in the review and within two hours I was called by the company. They were apologetic and wanted to send out one of their senior technicians. Mat came out and he was here last year. He was polite and professional and gave me a couple of findings, with no pressure to purchase anything, but did make suggestions. He was polite and professional and I appreciated that the company took it on themselves to make sure I was satisfied. I pay a little more than with other service companies that I had previously, but I trust the people at Sierra A/C and Heating.