replying to Tekkie®, Teresa wrote:
Hi Tekkie, mine is a fireangel st620. I didnt install it, it was here when
I bought my house. It flashes red normally but occasionally flashes green and
chirps occasionally, usually when Im trying to get to sleep. Shall I
replace it as the batteries are built into the unit.
--
for full context, visit
https://www.homeownershub.com/mainte...en-203358-.htm