For this job, I worked on an evaluation on this gas furnace system. As I arrived, system board had a open fuse code. I checked the fuse and it was burned, I replaced it and system turned on and burned the fuse again. I went through all the 24V wires and connected a new fuse and system popped it instantly. Lastly, I moved wires and tested, it turned out to be a bad control board. Options we're giving to the customer and customer approved to replace the board. Control Board has been sold and I notified the customer that the office will give him a call to get the job done. Thank you for choosing Comfort Experts, have a great day!