Had a panel start beeping at 2am, turned out to be one dumb thing I overlooked for 6 years
Got a call from a customer last Tuesday, 2am, panel beeping every 30 seconds. I figured dead battery or a zone trouble. Swapped the 12v battery, still beeping. Checked every zone, all showed ready. Sat there scratching my head for 20 minutes. Then I pulled the transformer off the wall outlet and saw the plug had worked itself loose over the years, just barely making contact. Pushed it back in, beep stopped, whole thing was fine. Now I always check the transformer connection before I touch anything else on a service call. What is the weirdest thing that ever fooled you on a trouble call?