Dispatch fee must be paid prior to a technician being scheduled. We allocate one hour for diagnosing the problem. If it takes longer than that you will not be charged for the extra time unless there are extenuating circumstances, which will be discussed with you before proceeding. I am a mobile RV tech, so I don’t have the space to stock a lot of parts. If I need to order parts the repair will require another trip, but no service charge.