Replacing a bunch of smoke detectors

[mpeirce]

Last night another of our smoke detectors started it's battery-needs-replacing beeping at 2AM. It was especially fun since I accidentally pulled down one of two smoke detectors that is tied into our alarm system (it wasn't the unit beeping, but 2AM...) so it set off the house alarm and our monitoring company called. Fun at 2AM...

We've had the house for 18 years now and it's (past) time to replace the 9 smoke alarms that came with the house. We do know that at least the one by the kitchen still detects smoke ;-)

I was set to buy a six pack of the First Alert 9210 wired + battery units on Amazon along with three First Alert SC05CN Wired + battery smoke + CO detector units.

The 9210 are basic ionization sensor smoke alarms, while the SC05CN's add a carbon monoxide sensor and the smoke sensor is photoelectric (supposedly better). I'd put one of these on each floor.

But today I was at Costco and noticed they had sealed battery First Alert units that are also photoelectric for only a $1 more than my six pack 9210's.

How do people feel about sealed battery vs replaceable batteries. Sealed seems better to me, but what do I know?

Likewise, does anyone really know if photoelectric sensors are better than ionization sensors?

Thought I'd ask before I bought these.

[GrayHare]

Can the sealed battery be replaced after it wears down? If not, you'll have to replace the whole unit in the future rather than just the battery.

[Senator]

Kidde has a recall on hard-wired combination CO/Smoke detectors. I just replaced ~25 of them.

Go to their website, anyone can buy the combo units for 50% off, free shipping. Just click the correct link. If you have the right dates, they are free.

If the sealed units have a 7-10 year battery life, it's time to trash the detector anyway.

[skipro33]

Something to consider is what the wiring in the house is like. If you buy a detector that fits the same plug that is already in place, it will make it a lot easier to swap out. I added on to my house and my electric contractor recommended one from Home Depot. Worked great with the rest of the house's alarms in that, when it was tripped, all the alarms go off.

[Senator]

Quote:

Originally Posted by skipro33 Something to consider is what the wiring in the house is like. If you buy a detector that fits the same plug that is already in place, it will make it a lot easier to swap out. I added on to my house and my electric contractor recommended one from Home Depot. Worked great with the rest of the house's alarms in that, when it was tripped, all the alarms go off.

All the hard-wired detectors I have ever replaced had a new wire plug to replace the existing plugs, if needed. Just wire black to black, white to white.

[jonat]

The "sealed battery" models use a lithium (not lithium-ion) battery. They should indeed last until the detector needs replacement for the sensor. But that's not for hardwired detectors. (I do use lithium batteries in my hardwired detectors so they don't go beep at night...)

There are adaptors to switch among brands of wired detectors. I have seen them at Home Depot.

[SH09022016]

Ionization alarms are designed for "fast flame" detection where Photoelectric are for smoldering fires. Ionization alarms usually react a little faster. Ideally you should have a mix of both types, say Ionizations in the bedrooms and Photoelectrics in the hallways, etc...

[RobbieB]

My small house uses 1 combo detector hard wired and lifetime battery backed up. Toss and replace every 10 years.

[Bamaman]

Building code often requires smoke detectors to be linked to where it one goes off, they all to off. And they will be 110 volt units with 9 volt battery backup. Unfortunately, such detectors are of very low quality with 5 units coating only $25.

I once had a pit bull and those smoke detectors just about drove him crazy. He would have a fit and start tearing up upholstery when alarms went off. My detector wiring had a short and I had to unhook them all.

I replaced all my detectors with better quality Kidde units that were battery powered and not linked. They too do the job.

[RobbieB]

I think mine cost forty bucks each.

[omni550]

And if anyone wants to know why the smoke detectors always start chirping at ~2am....

[omni550]

FYI, Florida passed a law a couple of years ago that mandates that all new smoke detectors sold in the state must be of the "sealed battery with 10-year life" variety. Someone told me that sometimes renters will remove a 9-volt battery from a smoke detector to power a toy or something...and forget to replace it. And a missing battery in a smoke detector would be discovered after a fire.

As mentioned upthread, after 10 years of collecting household dust, a smoke detector NEEDS to be replaced...whether of the 9-volt or sealed battery type.

I have one in my condo living room that is often tripped whne I'm cooking (browning or toasting something often sets it off). I'm looking to replace it with a photo-electric type (which is supposedly less sensitive to cooking-type emanations).

omni

[FUEGO]

Quote:

Originally Posted by omni550 And if anyone wants to know why the smoke detectors always start chirping at ~2am....

And here I was thinking my smoke detector had malicious intent. Makes perfect sense though it seems to be closer to 4-5 am here. When working, that meant it went off 1-2 hours before my alarm went off. AKA just long enough for me to get back to sleep before the alarm clock sounds.

I think I'll be upgrading to the lifetime battery model next time ours dies. I think our smoke and CO detectors die after the 7 to 10 year period anyway. Our previous one did right at the 10 year mark of owning the house (presumably I installed the unit right after buying the house). This time around I marked the date of installation/activation on the back of the unit so I'll know it's hit the 10 year mark when it starts going crazy this time around.

[mpeirce]

Great feedback. Thanks!

[skipro33]

Quote:

Originally Posted by Senator All the hard-wired detectors I have ever replaced had a new wire plug to replace the existing plugs, if needed. Just wire black to black, white to white.

Not saying they don't, just saying it's a lot easier if they are the same. Plug-n-Play instead of killing a breaker so you don't accidentally fry yourself while standing on a ladder and falling in the process. Might take several breakers if detectors are not all strung from the same power source. Then there's the rewiring with the wire nuts to remove and replace that plug, doing from a ladder and having to look up at the ceiling. I know that makes me a bit dizzy. If you have anything more than 8' ceilings, it gets to be even more of a pain. I have 23' cathedral ceiling in the great room area, 12' ceiling in the loft, 10' ceiling in the kitchen and 9' in the bedrooms. Even with 8' ceilings multiply times the number of detectors through out the house and it's just easier if the new units have the same plug as the old units.

[brett]

Some of ours will be up for replacement. I plan to purchase sealed units at costo. Perhaps even the dual units that also detect CO2.

We currently have smoke/fire detectors and CO2 detectors.

[jonat]

Quote:

Originally Posted by brett Some of ours will be up for replacement. I plan to purchase sealed units at costo. Perhaps even the dual units that also detect CO2.

Nit: CO, not CO2.

The sensors in CO detectors don't last as long as the smoke sensors - usually replacement after seven years is recommended for those.

[Senator]

Quote:

Originally Posted by skipro33 Not saying they don't, just saying it's a lot easier if they are the same. Plug-n-Play instead of killing a breaker so you don't accidentally fry yourself while standing on a ladder and falling in the process. Might take several breakers if detectors are not all strung from the same power source. Then there's the rewiring with the wire nuts to remove and replace that plug, doing from a ladder and having to look up at the ceiling. I know that makes me a bit dizzy. If you have anything more than 8' ceilings, it gets to be even more of a pain. I have 23' cathedral ceiling in the great room area, 12' ceiling in the loft, 10' ceiling in the kitchen and 9' in the bedrooms. Even with 8' ceilings multiply times the number of detectors through out the house and it's just easier if the new units have the same plug as the old units.

Great point, although unless it's the same model number, the plug will likely be different. Even with the same model number, it could be different.

I just got done changing 25 of them. All were Kidde, being replaced with new Kidde units. I had to change about 1/2 of the plugs.

And I never switched a breaker off... I did them all live, and it was pretty easy. IN my rentals, I do change switches and many outlets live too rather than switch off all the tenants appliances.

[ERD50]

Quote:

Originally Posted by omni550 FYI, Florida passed a law a couple of years ago that mandates that all new smoke detectors sold in the state must be of the "sealed battery with 10-year life" variety. Someone told me that sometimes renters will remove a 9-volt battery from a smoke detector to power a toy or something...and forget to replace it. And a missing battery in a smoke detector would be discovered after a fire. As mentioned upthread, after 10 years of collecting household dust, a smoke detector NEEDS to be replaced...whether of the 9-volt or sealed battery type. I have one in my condo living room that is often tripped whne I'm cooking (browning or toasting something often sets it off). I'm looking to replace it with a photo-electric type (which is supposedly less sensitive to cooking-type emanations). omni

Yes, since the detector has a limited life, and we now have affordable battery technology to match that life, I think sealed units make very good sense, and I'd support regulations for that.

I'd also support a regulation that all units have an easy to use short-term MUTE function. Not only is it convenient for cooking, it would result in fewer disabled alarms from these nuisance false-alarms. Instead of disconnecting the unit (or taking out the battery in the old ones) and forgetting to re-enable it, just mute it and it will return to service automatically in 5 minutes.

I got one with a mute button for our near-the-kitchen smoke alarm - so much nicer, and safer.

I've even seen ones that could be muted with a TV remote, which makes sense for ones you can't reach easily.

-ERD50

[mpeirce]

Quote:

Originally Posted by ERD50 I'd also support a regulation that all units have an easy to use short-term MUTE function.

I mentioned the mute button to my DW and she pointed out that she can't reach most of the units.

Of course, it's not that hard to drag a chair over to reach it...