Our furnace exhaust fan went out at 4am in the middle of January. The entire unit was shaking and vibrating the house and the housing for the fan was smoking it was getting so hot. I shut down the power to the furnace and called Dave Jones at 7am when they opened. I was able to give them the serial number and model number of the furnace and they showed up at 1:30pm that day with the right fan model and had it installed within 45 min. The furnace is working fine and we've had no problems with it since.
Highly recommend Dave Jones, especially if you need work done ASAP.