AirNow Services recently did a repair on my heating system. They fixed it and replaced the thermostat as well as a circuit board in it. I've worked with them for a long time, and I've always been happy with them in the past, but this time was a bit disappointing. I think they could improve their billing practices for one. I requested an itemized receipt and they sent me one in the mail with two sentences and no division of tax or product or warranty or anything.