Checking for DC on the signal line, I get functionally nothing. 20ma DC at most, and even that's something I'm picking up out of noise floor shift rather than direct measurement.

My _thought_ was that if the signal line was somehow floating in whole number volts (for whatever reason) than maybe somehow the right RF noise could kick it over.

The problem with _that_ is that I can now _also_ confirm that non-detecting units go off _exactly as long_ as a detecting device keeps saying it's detecting by putting voltage on the signal line. If that voltage goes away, so do the satellite alarms - and immediately.

And that's not what happens. We have to manually intervene and shut the alarms off ourselves.

(2/n)

#electronics #SmokeDetectors #why

The reason I paid meaningfully more than baseline for this particular set is that they report exactly which detector went off and why. That way, if it were the signal line somehow triggering the alarms, none of them would claim to be the originating unit; they'd all report it came from the signal backbone.

But they don't. There's always a unit claiming to be the active detector and it's always smoke (and there is *never* actually smoke), and none of them shut up until we shut off that unit, which sometimes seems to require removing it from power.

So today's afternoon check was basically just another way of confirming what we already knew, and I guess I've done that now, but...

(3/n)

#electronics #SmokeDetectors #why

All _that_ does is get us right back to where we started, which is, "we have alarm after alarm after alarm of different makes, methods (ionisation, photodetector), and models which just in this house are determined to go off randomly, usually but not always at night, for absolutely no detectable fucking reason, and then pass self-test just fine afterwards."

And no, regular cleaning - even weekly cleaning - does not help. I do _all the things_. None of it stops the problem.

(4/?)

#electronics #SmokeDetectors #why

If you're new to this adventure, I have heard this exact same story from _many other people_ at this point - though nobody I've talked to has said they've literally taken metres to the signal wires to verify that way.

Regardless, I know it is not just us.

What I've been told from others who deal with this is to RMA individual units that trigger randomly one at a time until you end up with a set that doesn't. And I guess that's what I'm gonna do, but

holy shit, team

holy shit

(5/6)

#electronics #SmokeDetectors #why

this is the opposite of fire safety

this is the opposite of how anything like this should ever work, I mean

what if all the RMAs are getting you are a set that won't go off even when they should?

but whelp

guess i'm gonna find out

'cause this sure ain't workin'.

(6/6 fin)

#electronics #SmokeDetectors #why

@moira I scrapped our cheap smoke detectors that had a lot of false alarms and got expensive name brand smoke detectors instead (like 40 bucks a piece). No more false alarms - only real detections (like bread stuck in the toaster).

Its really not good to get a call from a neighbor stating "your house beeps, but it sounds like the temperature warning of a fridge or something" just for me to confirm "ah thats just one of the smoke detectors. If this is going on for a few hours now and the house is still fine, just ignore it".

I don't know what would be a worse outcome: There is a fire but it is ignored as the smoke detectors sound like a forgotten alarm clock or its a false alarm and the front door gets kicked in to check what's going on. Both cost more as a few of the expensive smoke detectors.

@stereo4x4 Yes, that's what we did too, as per the thread. It didn't change anything _other than_ confirming that it is in fact individual detectors going off.

(These have voice messages, they have origination identification, they have CO maximum count reports, etc. Quite nice. Or would be, if they didn't go off at random, like every _other_ make and model we've tried.)

@moira

Your thread makes me realize that this stopped being a problem for me when I started running air purifiers all day every day

I didn't get new smoke alarms, and I didn't start cleaning the house better. So I think this is the only thing that changed

I have a cat, and I suspect it's a cat hair in the air that gets them, but I don't know