The normal service fee is $150 an hour for the first hour then $150 an hour for each additional hour divided into 15 minute increments. Parts and supplies to complete the repair would add an additional cost.
Example: first hour is $150 and if we are there for an additional 15 minutes that would add an additional $37.50 (150/4=37.50)and would bring the total service charge to $187.50 plus any additional cost for parts and supplies needed to complete the service call. I do not mark-up the cost of parts needed for repairs. You pay what I pay.
The service fee covers the cost to operate my service truck (fuel, insurance, maintenance, etc) and for my time to come out and do a through diagnostic check of the issues you are having with your RV to insure a proper repair to fix it right the first time.
I will have you show me the issue/s you are having and try to get them recreated in order to have a better understanding of what might be causing the problem. This will allow me to better diagnose the problem and potentially save you money with a faster repair.