All Service Calls start with a system assessment. Sometimes a simple reset will re activate the unit, for a short period of time and the issue will arise again.  Many boilers store error history and in many cases it will indicate what needs to be done. In some cases there is no error code or error history and we will have to troubleshoot in order to duplicate or re-enact the failure. Once we find what causes the error we can repair or replace parts. We stock a lot of parts so it's common we will have the parts on hand to expedite the repair. In some cases parts may have to be ordered.  Once we diagnose the issue we will propose various repair and or replacment solutions that fits your budget and schedule.