Caddx NX8E fire zone issue

[JimS]

Have the panel in the house and added a run to a detached garage with a NX216 expander and keypad for that building on a separate partition. It is working but sometimes I get a fire zone trouble fault with beeping and the fire LED flashing when I disarm. I can clear it and it's good for a while. The house has 4 wire smokes so the system is set for 4 wire. The detached garage has 2 wire temp sensor type sensors (just switches based on temp - NOT a 2 wire smoke). I wired them with a 3.3k ohm resistor as would be done with a 4 wire system and connected them between the zone input and common as for 4 wire rather than the 2 wire connection and resistor way. I just double checked all that. I only found 1 location to set the fire to 2 or 4 wire so did the wiring as 4 wire but suspect that may be why I am getting zone faults on the expansion partition. Any ideas on how to troubleshoot this or how to resolve?

 

[JimS]

Had this happen again and think it was the fire zone trouble. At first I thought it was more serious trouble and system didn't disarm but saw the fire icon flashing on keypad and the keypads kept beeping (it would stop briefly when punching keys). It was early and I think I tried the fire zone reset but may have gotten it wrong - in any case it didn't stop the beeping. I called the monitoring company and no alarms were reported. We had a case of the panel seeming to loose it's mind in December and finally got it working properly again with some help from the monitoring company but that seems to be a separate issue. Need to figure out the fire zone issue. Thinking some of this may be due to aging electrolytic caps as the hardware is 20 years old but that's just a guess.