It might be a little early for you and a remote. Service is a great way to start. I personally don't think customers should be billed for your learning curve. I gave away a lot of time in the beginning for the opportunity to learn and keep the customer. I know of people though that billed several hours due to incompetence on a job I could knock out in an hour. In most cases finding a valve with a 521 and getting it repaired shouldn't take more than two hours.