I have used Larsell Mechanical Service several times now. Every time they come out, they do some work with the thermostat. But it seems like they just mess around with it a little bit until it works again, but they aren't addressing the real problem with the furnace. They never seem to get it right. Recently, I was billed for two hours but he wasn't working for two full hours. I felt frustrated because I had to wait so long to have the furnace fixed. He spent most of his time coming and going. It was also a little high priced in general.