Many old-timers are still behind the times with advice. they neither refer to good code nor to manufacturer’s specs, but to long-ago-learned rules of thumb and work-arounds to get by. Still close to being a DIY, they get by with luck and the laissez-faire or know-nothing part-time inspectors.
You, Sylvan, know and follow code, and then take responsibility beyond that. There lies the large gap between the guesser and the professional. Mine was not a statement saying there were NO professionals before 1990. It was an observation of what was tolerated legally.
1990 is the approximate time the heating manufacturer engineers insisted that the technicians follow the engineers in the traditional hierarchy of engineer, master, journeyman and apprentice. The high-efficiency DOE requirements forced the manufacturers to declare requirements or the burners would not deliver the efficiency after changes by the techs in the field. DIY’s and 10-day wonders were tolerated and not challenged before that. The installer is liable, but even more so if he didn’t follow the factory instructions.
Do you still remember the days when the boilers came with general specifications and NO installation instructions and when the service instructions were general and there was no nozzle specification on the oil boiler nameplate? The days when a tech could play with the chamber size and the oil nozzle angle and gph, then setting the fire by color? Does anyone take the liablilty for plugging orifi or changing from natural to LP or vice-versa without an approved conversion kit?
The requirememt to diligently follow the manufacturer’s specs has spread throughout the PHVAC industry, so that old rules of practice are no longer enough to ‘get by’ and more careful litigation-awareness is unavoidable.