Had a zone expander die on me mid-install in a crawlspace in Phoenix

I was down in a 120 degree crawlspace wiring up a 16 zone expander for a new build. About 40 minutes in, the unit stopped accepting any new sensors and started throwing random trouble signals. Checked the power supply first, then realized the board had a cracked solder joint near the transformer. Swapped the whole unit with a spare I had in the truck and finished the job. That was a brutal 3 hour lesson in checking hardware before you start running wire. Has anyone else had a zone expander fail like that on a fresh install?

2 comments

2 Comments

barnes.shane1d ago

The cracked solder joint near the transformer is a common failure point on those boards. I've seen it happen a few times, usually when the unit gets banged around in shipping or if the installer mounts it too tight and the board flexes. What I do now is before I run a single wire, I bench test the expander with a 12v battery and a couple of spare sensors. Takes five minutes and saves you from crawling back out. Also, those Phoenix crawlspaces are no joke, I keep a cooler of ice water and a wet rag in the truck specifically for days like that. Sucks you had to learn it the hard way.

irishenderson1d agoMost Upvoted

Honestly @barnes.shane, a cooler of ice water in the truck? That's wild.