When I realized the temperature was dropping, it didn’t take long for me to call the Heating, Ventilation & A/C company. The first thing they asked me was if my control device was working. The light was on the display and I was pretty sure that meant something, however the temperature was only sixty degrees in the house. I tried turning the control device up, however nothing happened. I thought that if the battery was dead, I wouldn’t have a display reading, so I naturally assumed there was something wrong with the oil furnace. They sent an Heating, Ventilation & A/C company to the house, and he evaluated the control unit. He changed the batteries, however nothing changed. He then went downstairs to look at the oil furnace. After almost half an hour, the heat wasn’t turning on, and he was back upstairs. He said he was going out to the service van to get a new control unit. Even though the batteries weren’t dead, sometimes a control device would quit working. He brought in a new programmable control device and upgraded the seasoned control device with the new a single. Within seconds, the oil furnace was working again. I could not assume a control device would make that much difference. I thanked him for coming to the apartment so quickly and asked for the bill. The only thing he charged me for was the new control unit, and he took time to show me how to program it. I was so grateful that I offered him a tip for coming to the house. He tried to refuse it even though I said if he didn’t take the currency I was going to call the Heating, Ventilation & A/C company and tell them he forgot to leave the bill.