Last week the central vacuum would not turn off. It is a Modern Day Silent Master S5. I couldn't figure out what was wrong so I unplugged the unit. I called the installer, All Makes Vacuum and Sewing Machine Co., who I also purchased it from, to see what they could do. The owner, Carl Tice, came out yesterday and in two minutes he removed the vacuum and put it in his truck. He thinks something went wrong with the circuit board. Today he returned with a new circuit board already installed in the vacuum and put it up in 30 seconds. No questions asked, it works great, and I got great service!!!