Bernard servicing is far more lucrative than installs in most cases you just need a lot more of it!
but I imagined that a boiler service would be a profitable, pleasant and repeatable activity for an RGI.
I make the distinction between "servicing" and "diagnostic and repair".
Servicing is generally a standard list of things to check, clean and maybe replace. Requires little if any diagnostic skills. Been there, done it in the early years of my career. Yes it was very lucrative and at times quite enjoyable. But there were times when it was a bit of a boring routine doing the same things to several identical machines at the same location on the same day.
Diagnose and repair was and is very different. It requires the ability to think out of the box to determine the fault and then replacing the only those parts that were known to be faulty.
Many ( too many ) repair "technicians" do not have the necessary skills to fault find other than by changing parts until the fault is no longer there. Charging the customer for all the parts changed even when only one of them was needed to be changed.
That said the manufacturers fault finding flow charts are not always that good at encouraging proper diagnosise of the fault and seem to prefer replacing parts rather than precise determination of the fault. The use of test equipment seems to be avoided.
Fan not running.
Change fan
Fault still there
Replace old fan, change PCB
Fault still there
Replace fan again
Fault still there.
Give up, go home and phone tech support in the morning....
The original fan had gone short circuit and as a result the fan controller on the original PCB had been destroyed
The new fan didn't work because the fan controller was destroyed
Putting the original fan back in and changing the PCB resulted in the fan controller on the new PCB being destroyed.
A couple of tests with a multi-meter would have have enabled the faults ( fan and PCB ) to have been found and thus avoided the destruction of a second PCB
