Have been with ADT for 13 years. I have decided to switch due to their bad service. A wireless sensor was out of battery two years ago. Despite my repeated calling and request for a battery, nothing has been done to fix the problem. Last night, the carbon monoxide detector started to beep intermittently (usual sign of maintenance issue). I called ADT service line and was instructed to remove the panel cover and the batteries to stop the beeping. Once I removed the panel, I found that the detector was hard-wired and there were no batteries. Touching any metal part inside could have electrocuted me. There was an expiration date of the detector written behind the panel cover (to be replaced by Oct 2019). Again, I questioned the agent why ADT didn't replace it last year. To my surprise, she said that it is the customer's responsibility to notify ADT when to replace the CO detector. I have never heard of something like this before. A customer has to tell a security alarm company when to replace a piece of equipment. If the expiry date of the equipment is concealed behind the panel cover, are we supposed to unscrew every piece of equipment once a year to check the expiration date? It is a joke. Time to switch to another more responsible corporate citizen.