Hi All

Local code requires interconnected, 110v powered, smoke and CO detectors in residences. I'm in middle of rewiring and wondering for best location for CO detectors. I must have one per floor.

I have a 2000 sq ft house and am putting one on the wall below the outside stringer on the stairs.

The stairs make a turn (half landing) 3 risers before end of stairs. Wondering if that's a good location, or better to be in upstairs hallway.

Incidentally, I'm puzzled how combination smoke and CO detectors work. I seem to recall reading that smoke detectors should be placed on, or within 6" of a ceiling and that CO detectors should be at least 15" away from ceiling. So how on earth can I locate on (less than 9" long) that satisfies both requirements?

Regards

Mark