warning Honeywell

Error Code One short beep (about every 30 seconds)

System is in test mode, low battery is detected at a transmitter, or system will autoarm within 10 minutes.

? What Causes This

Test mode is active, wireless sensor has low battery, or autoarm timer is running.

How to Fix It

Exit test mode if active. Replace battery in low battery transmitter. Allow autoarm to complete or disarm system if needed.

Source: page 50 of the official manual

From the manual

Manual page 50 — Honeywell error One short beep (about every 30 seconds)

This error code appears in:

Honeywell Vista-20P Security System