Instructions for replacing batteries in FM Electronics wireless detectors:
Enter engineers code in control panel (4 6 7 9) for 4000E panel (PIN 0 4 6 7 9) for 4000X panel.
Replace batteries as required, ensure that the detector lid is correctly aligned to allow the PIR to work and the tamper switch is depressed.
Key in 4 8 on control panel to exit engineers mode.
Allow detectors to 'settle' for 20 mins before carrying out any tests.