This could be for a number of reasons.
- Key Pad may have a low battery or bad connection. Check the battery connections and polarity, if OK replace the battery.
- Siren batteries may be completely exhausted. Check Siren batteries by removing the Siren cover, if there is no tamper alarm when removed, replace the batteries
- with new alkaline equivalents.
- Key Pad not learnt-in. If Siren produces a tamper alarm when the cover is removed, and the Key Pad is OK, learn-in the Key Pad.
- Siren could be out of radio range.