Had a problem with the booking -- expected a call in the AM of the designated day but when I didn't get one by noon, I called back and they had no record of my appointment (although they did have a record of my name and contact phone #'s). So, I was rescheduled for 2 weeks later in the AM. I did get contacted the day before to say it would be in the afternoon, then the day of the appointment to say they would arrive between 2 and 3 PM. They arrived a few minutes before 2, which was fine. As for the service, I wanted to confirm that when they were cleaning each duct, all the other ducts would be covered, and was told this would be the case (this is as per NADCA protocol of which AHS is a member). In practice, the upstairs hot-air ducts were sealed, but the downstairs ceiling ducts were not sealed, and when I questioned this I was told "this is the way we do it". The reason for sealing all the ducts other than the one being cleaned is so one being cleaned gets the full vacuum force, rather than air being sucked through open ducts. Finally, I was told that the procedure might cause some dust / particles to be released into the house but this would be cleaned up before they left. This was the case upstairs, but downstairs I had lots of vacuuming to do to clear up a lot of debris left by the procedure. My final complaint is that after they left, even though it was very warm outside, the furnace kept running. I eventually noticed that the thermostat was set at maximum (done for the testing as part of the procedure), so I set it down to about +55 F, but still the furnace kept running. After 5 minutes I decided to turn the furnace power switch off. I waited several minutes and turned it on again, and as soon as I turned it on the furnace started up again (blowing hot air on a warm summer day). Once again I waited 5 minutes, but it didn't stop. I tried this a few times, then called for help. They suggested I check the "auto" setting on the thermostat, but I don't have such a thing (just a temperature slider). I got a call back from one of the technicians who recommended that I turn the thermostat down to minimum, which I did. When I powered up the furnace again, it came on again, but turned off within a minute, so finally things seem to be ok. Despite all this, I've given a high rating because the service was friendly and efficient, and considerably better than what I've got from other companies I've dealt with in the past.