During today’s visit, performed maintenance and inspection on two furnace units. The crawlspace furnace unit would not ignite, showing error code 10 on the controller. Error code 10 refers to a faulty igniter circuit. Replaced the igniter and the furnace tries to ignite but will not ignite all burners. The burners need to be cleaned. Customer authorized at this time to clean the burners of rust and debris. After clean burners, the system ignites and operates normally at this time.