Fermax 3321 with error p16-33-20032001 - Ring Intercom - Ring Community

I tried to test the fermax 3321 with ring intercom which is compatible but I get error p16-33-20032001 The 3 wires are well connected and tested for connectivity for +, - and L. Don’t know what to do anymore, perhaps the fermax is not really compatible.

Ring Intercom, problema di comunicazione codice P16-33-20032001 con Urmet 1740/1 e staffa 1740/83 - Citofoni, videocitofoni e intercomunicanti - PLC Forum

Ring Intercom problem with Urmet 1704/82. Error code P16-33-20032001. Anyone knows how to solve? : r/Ring

Ring Intercom - Fermax 8022 not working - Ring Intercom - Ring Community

Fermax CITY VEO WI-BOX VDS 1-line color video door entry kit

Ring Intercom, problema di comunicazione codice P16-33-20032001 con Urmet 1740/1 e staffa 1740/83 - Citofoni, videocitofoni e intercomunicanti - PLC Forum

Elvox 940A Audio Issue - #22 by Sam_Ring - Ring Intercom - Ring Community

Ring Intercom, problema di comunicazione codice P16-33-20032001 con Urmet 1740/1 e staffa 1740/83 - Citofoni, videocitofoni e intercomunicanti - PLC Forum

Fermax 1-Way DUOX+ Skyline Surface Kit with VEO

Video Way Fi 7 KitThe kit includes1438 1/W WAY-FI Video outdoor panel with rain hood.1436 Color WAY-FI Monitor with 7” IPS capacitive

FERMAX F0 1431- 1/W Video Way Fi 7 Kit | FKGTC