I installed a dimmer for our dining room chandelier. It brightens and dims the light, but it doesn't shut the lights off completely. At the lowest setting, the lights are a very dim orange. The dimmer is the sliding type and doesn't push in to turn on and off like the round knob style does. The previous switch was one pole (had 2 black wires going to 2 screws and the ground wire going to a green screw. The dimmer that I installed is also one pole.

Do you have a brand and model number of the one you installed?

Could be you are having a chandelier with big resistance comparaable to that of the dimmer.. or let's say the lights are sensitive to little current... May be you need another dimmer suited to the type of bulbs you have.

EVERY dimmer has an OFF function. As long as the lamps are matched to the dimmer (IE: incandescent dimmer for incandescent lamps) it should work fine. The only problem would be an overloaded dimmer, but this would NOT make it stay on.

Either the one he has is broken, or he is not pushing it to off hard enough.

I'm with Stan. There needs to be a hard off on any dimmer.