Honeywell 5818MNL Recessed Wireless Transmitter

When it is time to replace the battery in your door/window sensor, you will see an alert on your system panel.

The Honeywell 5818MNL door/window sensor requires a 1.5-volt lithium AAA battery, which can be purchased from Indiana Alarm, local hardware store, mass retailer, or battery store.




Step-by-Step Instructions:

1. Remove the transmitter’s end cap by inserting the flat blade of a screwdriver in the cap’s slot and turning slightly counterclockwise.

2. Slide the transmitter PCB assembly out of its case, taking care not to bend the antenna during this step or later.

3. Remove the old battery, if replacing it.

4. Observe correct polarity and insert the fresh battery into the battery holder (position the battery as shown in Figure 2).

5. Slide the PCB assembly back into its case, battery end first (the reed switch end must be close to the end cap).

6. Replace the end cap. Line up the projections on the cap with the openings at the edge of the case. Press the cap gently against the PCB and turn the cap (via its slot) slightly clockwise, thereby locking it in place.