Since old Firex and new replacement have different wiring harness, the existing wiring harness needs to be changed.
If you don't want to rewire, you need to get a quick convert adapter Kidde KA-F and perform 3-easy-step installation:
Download PDF manual (English)
Download PDF specification
Download PDF manual (Spanish)
The Firex 4618 Smoke Alarm is an ionization 120V AC smoke alarm with battery back-up for single or multiple station use. It includes a Quick QuietTM False Alarm ControlTM feature which allows the user to quiet an unwanted alarm for up to 15 minutes. The 4618 has a front loading battery door, 85 decibel horn, test switch and dual purpose LED indicator; constant green “power on” confirms AC power is present and the flashing red displays alarm/battery status. The Latching LED feature clearly identifies the smoke alarm that initiated an alarm in an interconnected system with a flashing red LED. The LED will remain flashing until the test button is depressed on that unit. Our unique PowerLinkTM Tab is designed to allow the smoke alarm to be shipped with the battery already installed. It keeps the door from closing until installation, which prevents the battery from draining prematurely. The installer simply removes the PowerLinkTM Tab, closes the door and tests the unit. This results in a faster installation time. The dust cover eliminates nuisance call-backs by keeping construction dust and debris from causing false alarms.
This smoke alarm mounts to any single or 4” octagon junction box or square-to-round drywall ring and has 8” long pigtails with a Quick Connect harness for permanent connection. The 4618 is interconnectable with up to 11 other compatible Firex smoke alarms and 6 Firex heat, carbon monoxide or smoke/CO combo alarms for a total of not more than 18 Firex devices. When interconnected with other Firex smoke alarms, the unit that initiates an alarm will display a rapidly flashing red LED while the other interconnected alarm LED's remain extinguished. This Firex unit should be placed in singlefamily households or in each individual living unit of multiple-family buildings.Features & Benefits