Have a new customer with a starplus sts system. They say they hit the nigh button and then the calls are forwarded out of the system to the answering service.

How do you think they are doinging this.

I think that the night mode is programed to ring one phone and then that phone is forwared but I can't find the phone that is forward to the answering service.

Any help would be great. No wrong answers

The co ringing in flash 40 can be programmed to ring to a speed dial number. It doesn't have to ring to a phone forwarded off site. I only do it that way if the destination has to be changed on a regular basis by the user. If the night calls rang to menu and one of the choices was to ring the night service, then it would have to go to an extension first. Speed dial numbers are not one of single digit key stroke choices.

it could be setup when in nite mode it rings to the 149 or 148 SLT on the side of the cabinet and that is forwarded offnet to the answering services

Looks like. It not forward from the single line EXT. Try call EXT 148 and 149 and they just rang.
Any other sujestions

could it be a speed dial button labeled "night" ?

hit the button grabs line one ,dials #72 xxx-xxxx

when you go off hook and push the night button what do you hear ?

what is the "night" button programmed as

To check flexible button programming at the keyset:
1. Lift handset.
2. Press SPEED, then dial [7] + [#].
3. Dial [2] to select the KEYBTN option.
4. Press the desired flexible button(s) to display programming for the button(s) on the LCD.