It wouldn't set for Miss T so I came up and ran through the reset protocol. Though I repeated it three times, the WORD trouble remained in the corner of the panel and the E then 01 and 18 kept flashing. I called the alarm company and they said the alarm should still set if I had done the reset. I tried it and ... it set. 
"Call your ADT local provider in the morning to deal with the "Trouble" issue. Have a good evening."
At 9am I called our gal, and she answered immediately. Funny, but I had caught her in her car. She said as soon as she got to the office she would research the codes and call me back. Hmmm. Turns out, E18 is a low battery in the remote fob for the alarm. I popped the fob and didn't see the battery. She pulled up the video and said you hook the circuit board in this small hole in one end with a paper clip, pull it out, and boom.... battery is hiding on the bottom. Yup, a CR2032. Same battery that my Red Dots use and several of my instruments in the woodshop. I had a few on hand. Changed both and armed and disarmed the alarm. It gave a long BEEEEEP, and both fobs went BEEEEP and then.... the "Trouble" code....
Disappeared.
Sweet. Usually I have to schedule a repair and the ONE guy they have on staff is a week behind.
