ADT Heat Detector has power or battery problems

The checks in more detail

then fetch the battery type from the manual or the label inside the case, because models differ and the wrong type can be unsafe or give poor life. Put the system in test mode if the panel allows it and tell the monitoring company, open the case, remove the old battery, noting its direction, and fit a fresh one the right way round. Close the case so that the tamper switch is closed, and clear the low-battery message as the panel instructs. Choose a good-quality lithium battery of the right rating for the temperature range, since cheap cells fail early in extreme conditions.

If the message returns within weeks, the detector's environment is too hot or cold for the battery, the contacts are corroded or the detector is failing. Clean corroded contacts gently with a dry cloth, and replace the detector if the corrosion is severe. Do not ignore a chirping detector, because a heat detector with a dead battery gives no fire warning. Write the date inside the case and replace batteries on a schedule, once a year for harsh locations. Dispose of old cells at a recycling point and keep spares away from children. Test the detector after the change using the manual's method, and keep a record.

If you cannot reach a high ceiling safely, use a proper stepladder, with someone to hold it, or ask the installer. Where a heat detector sits in a hot attic, consider how often you can really reach it, because a battery that has to be changed yearly in a place you rarely visit is easily forgotten. Put a reminder in your phone's calendar for the same month each year and tell the installer which detectors are in awkward spots, since they can sometimes suggest a different model or a position that is easier to reach. Never rely on the chirp alone to remind you, since it stops when you are away from home.