Hi Guys,
I ran into a fellow who I had worked with 40years back doing building maintenance.
While having coffee and catching up on who is now dead, who screwed up big, who got fired and what we were doing now that we were retired persons. He had a tablet with him and showed me a U tube channel that serviced full size boilers, we watched a couple of videos and had a laugh over remembering doing some of the stuff and what they had left out.
the Channel is called the Boiling Point and is done by wareboilers, you should be able to find it with that.
Regards,
Gerald.