CARBON MONOXIDE DETECTOR FAIL SAFE MECHANISM

[230RN]

This is something I've never seen before, although I'm not experienced in residential-type medical and safety equipment.

Instrument:  Kidde model KN-COPP-B-LPM carbon monoxide detector, manufactured 03 Oct 2014 , three original Kidde-brand AA cells, device expiration date("Replace by") January 2025 (That suggests a radioactive sensing mechanism, like in a smoke detector.)

See Attachments below.

The issue: Pop-up barriers in battery compartment to prevent closing the battery compartment without replacing the three AA batteries (cells).

I got the thing in about 2015 (?) when they did a remodel of the apartment building's HVAC  system and they moved the furnace stacks from the roof to the side of the building.  I, in my ever-present paranoia, thought I kept smelling incomplete combustion , so I got this thing "just in case."  (Hey, I'm paranoid, right?  I mean I even own GUH-UH-NS, right?)

Anyhow, it gives a nice pleasant little green blink every minute or so to say, "Hey, I'm OK, boss, right here on duty."  It never gave an actual warning alarm despite my hand-wringing paranoia.

But about 4:00 AM this date I was awakened by a loud chirping every minute and it was a low battery warning ("L b") from my little carbon monoxide guardian.

So I opened it up and pulled the three AA cells and tested them and indeed they were pretty  damned low, not surprising, since they were original to the day I got the detector.  Like wow, right?

I wondered about the red arms that popped up when I yanked the batteries, but soon discovered they prevented closing the lid without putting new batteries back in.

I thought you folks might be interested in this little fail-safe mechanism and wondered if this was some kind of standard procedure for "medical" or safety devices.

Terry, 230RN

[HankB]

When I was in an apartment I had a battery powered smoke detector. Cheap-ass management thought the tenants should replace the batteries themselves, so I did - with one from the detector in the hallway outside my apartment. All this one did was chirp a bit with a low battery, and it COULD be closed up with no battery. The house I bought had no smoke or CO detectors, so I bought some and installed them - I don't remember them having a battery failsafe.

My current house is "all electric" so I don't need a CO detector, but when I bought the house (new) in 1996 it had the newfangled "hard wired" smoke detectors. Silly me, I didn't know "hard wired" detectors still had a battery, and the "low battery" warning doesn't just chirp, it sets off ALL the detectors in the house. Full volume.

This happened at 2 AM. Of course.

It took a little while but I figured out what was going on (with the detectors wailing away every couple of minutes) and from then on I began replacing the 9v batteries annually.

BUT - these detectors only last about 10 years. At about 9 1/2 years, they all went off. At 3 AM. So I replaced all the detectors, annually changed the batteries, and all was well. For 11 years, at which point they all went off . . . at 2 AM. (I sense a pattern here.) So I replaced 'em all again. Should be good for at least several more years. Though it never occurred to me to look for an "inserted battery" failsafe, I kind of remember a little red lever inside the 9v battery compartment - maybe that was it.

[Tuco]

This happened at 2 AM. Of course.

Of course.
And the bad battery is in the one 16' above a stairway.

[Kingcreek]

Thread drift warning
My mother bought a new single story home in a senior living complex. It was built with a crawlspace because she wanted hot water baseboard heat. About 5 years after she moved in the CO detector in a utility closet with the gas boiler and hot water heater started screaming at midnight. Her caregiver called 911 and they came and got her out of the house and called the utility company. They tested for gas and said everything was fine. faulty sensor maybe? Everybody went back to bed and it went off again an hour after they left. On the advice of FD or gas co Mom and caregiver evacuated to a hotel for the next few hours and gas co sent somebody out again next day.
This time he was more thorough and found nothing in the house again but alarms went wild when he opened the crawlspace hatch.
The sump pump had a backup 12v deep cycle battery that had died like lead acid batteries do and apparently that can set them off.

[WLJ]

Of course.
And the bad battery is in the one 16' above a stairway.

I always use lithium batteries. By the time the batteries need replacing often too so does the detector.

[230RN]

HankB, that little red lever sounds exactly like the ones in my CO detector.

I noticed them when I first set it up, but since I wasn't trying to close the compartment with no batteries, I kind of dismisssed it from my mind until this AM.

"Thread drift warning."  Oh, yeah, me, of all people on this board, would really be bothered by a minor thread drift like that. Good story, and actually, not off-topic.

My smellerator quit noticing the incomplete combustion smell in a short time.  Enough other people complained that they made adjustments to the furnace.  My general principle is that if something in the building is bad enough to bother me, someone else is bound to complain about it.

I still don't like the idea of the furnace exhaust coming out the side of the building instead of the roof, but I guess it's up to Code, so que será, será.

WLJ, the batteries that came with it were Kidde branded, "Golden Power GLR6A"  and "0% Mercury and Cadmium."

They pooped out two years short of the 2005 device expiration date.

I put a note in the battery compartment indicating they were replaced on today's date.  There's a note on the front that says it will tell you when the device itself expires.

Looks like Kidde had all the bases covered.

[Perd Hapley]

I wondered about the red arms that popped up when I yanked the batteries, but soon discovered they prevented closing the lid without putting new batteries back in.

I thought you folks might be interested in this little fail-safe mechanism and wondered if this was some kind of standard procedure for "medical" or safety devices.

Terry, 230RN

I don't know about other devices, but I've often seen them in smoke and/or CO detectors. I think they're fairly common now, or maybe even required in newer alarms.

[230RN]

^ Thanks, I was beginning to wonder about that.  I bought a smoke detector about five-six  years ago and it doesn't have a lid blocker. I just changed the 9UV in it last DST/MST switchover.  It was a bit of a bargain, so maybe they were getting rid of old stock.