How to Reset a Honeywell ADEMCO VISTA-20P

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Contact Honeywell customer service if your security system control panel fails to respond after being reset.


The default installer code is "4112," but this code may have been changed when your alarm was installed. If you have forgotten the new installer code, contact Honeywell customer service.

Honeywell International Incorporated is a conglomerate company that produces popular residential and commercial security systems. The Honeywell Ademco Vista-20P is a 48-zone commercial burglar and fire alarm from the Ademco Vista Plus security system series. If the AC power goes out, you may have to reset the control panel when the electricity is restored. The alarm system control panel can also be reset to clear any minor mechanical malfunctions. Resetting an Ademco Vista-20P security system takes just seconds.

Reset After Power Outage

Step 1

Locate the electrical service panel in your home's basement, garage or laundry room. Look for a putty- or silver-colored rectangular box that's about the same size as a phone book.

Step 2

Open or remove the cover on the electrical service panel. Locate the circuit breaker switch labeled "Alarm" or "Security System."

Step 3

Flip the switch "Off" and then "On" to reset your Honeywell Ademco Vista alarm system after an AC power outage.

Reset to Factory Settings

Step 1

Access the alarm's programming mode by entering the installer code, followed by "8," "0" and "0," into the control panel.

Step 2

Press the "*" button on the control panel, followed by the "9" and "7" buttons to reset the security system to factory settings.

Step 3

Follow the on-screen prompts to select the desired default programming settings or consult the Honeywell Ademco Vista-20P User Guide for customizable programming options and advice.


Megan Mattingly-Arthur

Megan Mattingly-Arthur has been writing professionally since 1998. She has contributed to various publications, including "Teen Voices" and "Positive Teens" magazines, as well as a book, "The Young Writer's Guide to Getting Published." Mattingly-Arthur is studying travel and tourism through Penn Foster Career School.