How Do I Replace Old Alarm Sensor Magnets?

Honeywell offers 3 different types of sensor magnets depending what type sensor you have.

Wireless sensors - Honeywell 5899 magnet. The 5899 magnet is the same magnet that is shipped with the Honeywell 5816 sensor but is compatible with all wireless door window sensors. The 5899 can be ordered in either brown or white to match your existing sensor. The 5899 magnet's dimensions are 1.5" long, 1/2" wide and 1/2" deep which is slightly larger than a typical magnet and can be used without the case if needed. Install the magnet no further than 1/2" from the contact when the door or window is closed, making sure to align the magnet along the long side of the wireless contact that has the magnet alignment marks etched in the plastic case. In addition to the magnet alignment marks on the side of the sensor case, the mounting plate has a plastic strip that can act as a guide for installing the magnet. If the magnet is installed on the wrong side, the wireless transmitter will not function properly and the zone programmed for that particular transmitter will remain faulted until the magnet is properly aligned. A plastic spacer is included with the Honeywell 5899 magnet, which can be used to properly align the magnet with the corresponding sensor when the door or window frame is not flush with the door or window.

Hardwired Contacts - Honeywell 945-M magnet. The 945-M is a surface mount magnet that is shipped with the 945T contact, but is compatible with many surface mount hardwired door, window sensors. Install the Honeywell 945-M magnet within 1.125" of the installed contact. If replacing an existing magnet with the Honeywell 945-M magnet with any other hardwired surface mount door, window contact, please check the magnet spacing gap for the contact before mounting the magnet to ensure proper spacing. The 945-M is available in white and brown.

Recessed Contacts - Honeywell PROBTM magnet. The PROBTM is a rare earth button magnet. Rare earth magnets are stronger than the standard magnets allowing users to use a larger magnet spacing gap when installing door and window contacts. The PROBTM magnet is ideal for the Honeywell 944TRE and Honeywell PRO51BTM recessed door and window contacts because both of them are shipped with a PROBTM magnet when purchased. However, you can use the PROBTM magnets with nearly any recessed door and window contact.

Each PROBTM magnet has a concave hole in the middle where a screw would be screwed to attach to a door, allowing the screw head to be flush with the top of the magnet and the edge of the door.