Heat Sensor (HDX-135 or HDX-200 or HDX-135Z)
Twist the cover counter clockwise and remove it.
Locate the battery.
Gently remove the battery from its connections.
Note the battery terminals (+, -). Putting in a battery reversed can damage the device.
Place a new battery in the device (CR123A).
Place the cover back on the base.
Twist clockwise until you hear a click.
SHARE US WITH YOUR FRIENDS!