Ferrell came highly recommended but was booked up the day we had a problem so we scheduled an appointment the next day and looked for someone else who could come out the same day to fix our heat. That was a mistake, Blue dot came out the same day(but later than they scheduled). I had done some of my own detective work on the internet and checked the thermocouple myself which showed good so was guessing that the gas valve was faulty. Blue dot came out and didn’t do any diagnostics or listen to my diagnosis they just tried to sell my wife a new furnace saying ours was on it’s last leg. When she turned them down they said it was probably the thermocouple but he didn’t actually test it or have the part to do it anyway. Said it would be $ 200 for a thermocouple(fyi: I replaced it myself later that night in about 10 min after picking one up at the home store for $ 12). Blue dot said if it was the gas valve it would be $ 1000 dollars but that might take several days to order and schedule a fix. After that poor performance we wrote off the $ 82 dollars they charged as a lesson learned to never call Blue Dot again. Called Ferrell the next day before the appointment to let him know we thought it was probably the gas valve. Compared to Blue Dot he actually listened to us and brought a valve along with him on the appointment. He ran a full diagnostic and confirmed it was the valve which he replaced for $ 560, almost half the price that Blue dot told us. Also checked the rest of our system and said it looked ok(no need for replacement). Said our thermostat was getting old and might need replacement but said we could do that ourselves if we wanted. Lesson learned: the good guys are sometimes booked up, but it is worth waiting a day to get it done right for a reasonable price.