I bought a furnace from Smart Home Works roughly 2 years ago and, long story short, it had not been working as well as it used to, as of late. Upon calling their support line, we were asked if we had changed our filters and they were confident that was the case.. A technician arrived about 40 minutes later and he changed the filter for me. The old one was DISGUSTING and there was an impressive amount of matted hair stuck to it. He left us a few spare filters as well, since we are entitled to a free filter every year, and instructed us to change it every 6 months or so. Thank you VERY much Smart Home Works! Your service was very much appreciated.