Let's discuss smoke alarms.

Rick Lee · Rick Lee's Garage

I'm pretty religious about this subject, since my house and life were saved by one about five yrs. ago. I woke up this morning to a chirping smoke alarm in about 1-2 min. intervals. I assumed this was a dying battery and it's time to change them all. I have the Firex brand, which plugs into the house wiring and also has a 9 volt battery. I assume the battery is a backup to house power. So how the hell is thing still chirping when I have it unplugged and the battery removed? Do these things have internal batteries that store auxiliary power? This alarm is dated Aug. 2000. Time to upgrade or just swap out batteries?

Zeke · 04-08-2011, 08:29 AM

No internal battery that I know of. Although a new and improved model may have that. It's a good idea as I have had to replace batteries in smoke detectors that were installed in rental units and disabled by tenants. One that won't shut up until it's fixed is what was needed.

Evans, Marv · 04-08-2011, 08:46 AM

Maybe it's taken on a life of its own. I have smoke alarms like you described in the bedrooms & hallway, don't know if they're the same brand or not. One problem I've had intermittently is them going off mostly in the middle of the night of course. It seems like the contact between the 9V battery & the alarm gets weak (for lack of a better term) and the alarm thinks it needs changing. Part of the problem is they don't chirp, they just go off, and when one starts, it sets off the others. At first I thought it was weak or dead batteries, but after I tested a couple, they tested what looked like a full charge. I found out if I remove the battery and reinsert it, it works fine after that (until it happens with another one). I figure that reestablishes a good contact between the battery and the alarm.

A930Rocket · 04-08-2011, 08:51 AM

Remove the battery and hold the test button down until the chirp dies. I think it has a capacitor or something that allows it to keep chirping.

Anyway, this has worked for me.

krystar · 04-08-2011, 08:52 AM

there's usually enough capacitor inside to keep it going with a couple more chirps. shouldn't last long

vbaron · 04-08-2011, 09:57 AM

Yes, it's probably the capacitor taking time to discharge. Incidentally, I'm in the Commercial Fire Safety business and I believe the residential recommendation is to replace your detectors every 10 years. On the commercial side, we clean and test detectors on a scheduled basis. Residentially, the assumption is that does not happen and replacing them after 10 years is best.

Replace your batteries at least once a year!!!

Rick Lee · Rick Lee's Garage

As long as we're in the presence of a pro, Vbaron, what's your take on the garden variety fire extinguishers from Home Depot and Lowe's? Are those gauges on them reliable? Seems I've had mine for a loooonggg time and they always read green.

VINMAN · 04-08-2011, 10:04 AM

The readily available store bought extiguishers are fine. Just buy bigger than you will need. Personally I have a couple commercial grade dry chem ones around the house.

Hugh R · 04-08-2011, 10:27 AM

You should shake them once in a while, the powder that does the work can settle to the bottom and you'll just get a puff of propellant when used.

Rick Lee · Rick Lee's Garage

Quote:

Originally Posted by VINMAN

Personally I have a couple commercial grade dry chem ones around the house.

I got sprayed with one of those in my dorm room in Germany about 20 yrs. ago and I swear, I still have some of that powder stuck in my things. We were goofing off, all drunk and stupid and a neighbor knocked on my door. When I opened, I got the full blast in my closet-sized room. We looked like the Three Stooges in a flour fight after that and had to sleep in a neighboring room after showering.

svandamme · svandamme's Garage

there's radiactice crap in there too...

GH85Carrera · GH85Carrera's Garage

Most detectors have a date stamped on them. Replace the entire detector if it is more than 10 or 15 years old.

vbaron · 04-08-2011, 04:26 PM

I can't speak about extinguishers, just the alarm systems...still the suggestions above should be good.

Vin

Joeaksa · 04-08-2011, 04:43 PM

My smoke detectors are the same, a 110v hookup to the house and a 9v battery backup. Like Ricks mine are as old as the house so prolly 10 years old.

Last time I looked HD or Lowes did not carry the dual voltage versions. Anyone have a good place to buy them?

Joe

Big Ed · 04-08-2011, 04:47 PM

Joe,

The line voltage detectors with 9V battery backup should be readily available at your local HD or Lowes, or any other hardware store for that matter. You could also try an electrical supply store if you have one nearby.

And to the OP, you definitely want to replace the detectors every 10 years or so.

Rick Lee · Rick Lee's Garage

I'm headed to HD in about an hour to see what they have. Might try to buy in bulk from McMaster too.

VINMAN · 04-08-2011, 05:20 PM

Quote:

Originally Posted by Rick Lee

I got sprayed with one of those in my dorm room in Germany about 20 yrs. ago and I swear, I still have some of that powder stuck in my things. We were goofing off, all drunk and stupid and a neighbor knocked on my door. When I opened, I got the full blast in my closet-sized room. We looked like the Three Stooges in a flour fight after that and had to sleep in a neighboring room after showering.

Yeah those things can make huge mess. I love when we pull up on a car fire, and the PD gets there before us. You can always tell because everything around the car that is burning, is covered with powder except the car itself.