Have a fairly new hot water Burnham ESC5 boiler, which runs great, but as the end of it's second heating system approaches it's time for it's first routine service.
Are there instructions describing specifically how PM should be done, not just a list of the items that need to be done? I see lists of things.... but alas not how they should be done.
What is involved in a complete maintenance call and how would I know if it was done well?
Also, if I were to stockpile some spare parts, what are the first things to typically break on these boilers? Parts for the now gone oil burner were easy to come by, not so sure for model specific things on this boiler and don't want to have to face a search for parts on at the most inopportune time.