The Saturday morning I called Mark, he paid a visit to our house in a couple of hours and suggested to replace the broken furnace with a high efficiency one. He delivered the new furnace on schedule,they started the installation immideately, and stayed until midnight to finish it. I also called him today as I thought the fan was not working on "on" position. He came with his associate and found out that it is working but very quietly and at a low speed. He left our home without any complaint. Keep up good service Mark!