Arrived to remedy and system. Upon inspection of the system, found a fault code pertaining to the system pressure switch. Verified operation of the pressure switch and verified that it is relaying its signal back to the control board. Control board is still displaying the fault on the pressure switch circuit. Tested other components of the safety system. System was providing different vault codes for each different test. This tells me the system is functioning properly on each of those circuits. Determine that the issue is the furnace control board. Spoke with homeowner about repair solutions. With homeowners approval reached out to a field supervisor to provide repair and replacement options. Homeowners will be getting a new furnace installed tomorrow. Left space heaters to heat the home in the meantime.