That is not disputed among techs, and it's illegal according to Fire Code to install it anywhere else. So the installers switched out the Control Panel and keypads, including switching out the 3K resistors at the Panel for 2K resistors, as prescribed-but the reason I mentioned the burg EOLRs at the panel is that Fire Zone EOLRs NEVER go anywhere except at the End of the Line-the last fire sensor (smoke sensor or heat sensor) on the fire loop. (There is difference of opinion in the alarm tech community whether this is acceptable practice, but I'm in the camp of installing home alarm burg zone EOLRs at the panel, for reasons I'll discuss with anybody who's interested but it's not relevant here.)

Now, it's not unusual for the 'EOLRs'-i.e., the 'End of Line Resistors' that the manufacturer says should go at the end of the zone loop-it's not unusual to install the burg(lary) zone EOLRs on the Panel, the main PCB board, at the beginning of the zone loop. One memorable example of this comes to mind, from years ago: A couple of installers upgraded a home system from one panel that used 3K zone loop end-of-line resistors (EOLRs), to a panel that used 2K EOLRs. A zone can 'work' when its resistance is 'way more or less than it's supposed to be, and manufacturers won't tell you what the tolerances may be, and for good reason: Installers aren't supposed to be trying to see how much they can get away with, they're supposed to be installing the resistance values prescribed in the manuals. I don't know what tests you ran to ensure it's 'working', but I assume everything 'worked' as expected-but it doesn't matter. There's a reason it directs you to use 3.74K resistors. Follow the Installation Manual instructions, and put 3.74K resistors on the lower zones.

Nx8 v2