What is tripping the alarms? Smoke or CO? I use the Kidde Firex i4618 AC/battery smoke alarms and have zero false alarms. Ten of them in the house. Cost is about $11 each in pkgs of 4 (new on eBay). I would use these smoke alarms and add in a couple SEPARATE carbon monoxide alarms in the occupied bedrooms.

I have one each of the First Alert 9120 ionization detector and First Alert 7010 photoelectric detector (they should be used together because they react to different types of fires). They never go off unless there's a reason. Note: these detectors have a "b" suffix to indicate they have battery backups. I want didn't batteries because they caused more false alarms than the detectors themselves. But the non-battery models aren't available anymore.

First Alert 3120B combination detector is CR-recommended.

That's a great price - when I looked it up on Lowes and they were $44 each.

I also got Kidde smoke alarms (a six pack….with NO carbon monoxide detectors)….i12010s

(purchased on Amazon

Kidde Smoke Detector, Hardwired Smoke Alarm with Lithium Battery Backup, Interconnect, Test-Silence Button, Pack of 6 https://a.co/d/gADrm0o).

These alarms have permanently installed 10 year batteries so no changing batteries for ten years! When the batteries die, you simply replace the entire unit. No wiring necessary just plug in the pin connector and you’re good to go.

My old mounting plates will need to be removed and the new mounting plates (which are included with the new alarms) will be installed. It’s a simple matter of removing the old plates and screwing the new plates into the ceiling. The pin connection is the same so no problem there. But since you have First Alert, if you change brands you will need to find out if they use the same pin connectors. If not, you will have to re-wire with the proper connector (electrician needed if you can’t do it yourself).

So, my advice would be to look for alarms with 10 year batteries that are reliable and that have the same pin connector as you already have.

Just got six replacements (with 10 year batteries) the other day ready to be installed.

I have several detectors that were malfunctioning and they would ALWAYs start beeping in the middle of the night and ALWAYS when my husband was out of the country! Such a pain. Btw, ANY smoke alarm has a limited lifespan and usually start to malfunction after 8-10 years and will need to be replaced.

Be mindful that not all Ebay sellers offer genuine products. Some Amazon sellers have sililar issues and both sites sometimes have counterfit products. I appreciate a great value as much as anyone, but do be careful to have any $11 units checked out by your local Fire Dept. to ensure the value priced units are legit. Your safety will be riding on these so verifying is worth your time for sure.

We had all new fire alarms installed a few years ago: Kiddie, model i12060A and 2 Kiddie plug in Carbon Monoxide / Explosive gas alarms: model KN-COEG-3 (one CM on ground level and one upstairs). They all work great, no issues and no false alarms.

For those that are skeptical, the eBay fire alarms referenced above were in Kidde packaging (bulk, brown box, but Kidde factory labeled), they were the real deal, and I've bought the 4-packs several different times. For mtvhike, the i4618 alarms individually are $17 every day at the box stores.

Are you sure they aren't working properly? CO is pretty sneaky...