Universal Security Instruments1204 Wire-In Smoke Alarm with Battery Backup (4 Pack)

17 year old alarm chirped even after replacing battery. The old USI alarm had failed. This USI alarm was the perfect replacement even though the model# was different. The USI website confirmed the models were interchangeable. Comes loaded with a protected battery, the alarm, and the base. The alarm plug connected easily to the existing base. Problem solved!

All five of our interconnected smoke detectors had exceeded their 10 year lifespan and needed to be replaced. These identical smoke detectors filled the bill and are performing as expected. A good value for the money.

It was time to replace the old smoke detectors in my house and I was able to match the old ones easily with these new one. The connections were the same and everything fit perfectly in the end. Easy installation for the DIYers out there. I am all set for another 10 more years.

Replacement part

For DIY alarm REPLACEMENTS---It may be initially confusing when opening the box as the contents look to be inconsistent with a "plug/play" installation. However, the unit in the box that has 3 bare wires coming from it is actually a new base plate for new installations, not needed for replacements. The REPLACEMENT alarm module is INSIDE the base plate, has the connector installed and is identical to the alarm being replaced. Just twist the 3-wire base plate and lift it off to reveal the actual replacement alarm. The new alarm connector can then be plugged into the EXISTING pre-wired base plate connector, replacing the current alarm, and with a twist of it back onto the base it's ready to go for another 10 years. But be sure to note that the unit arriving in the box with the 3 bare wires is just the base plate which CONTAINS the replacement alarm module. Once realized it becomes a simple installation. Instructions in the box are extremely poor for replacement installations.

I have a new-ish home with 14 smoke detectors that are hard-wired with the battery backup. Bought these because they were the same brand and model and I wanted the easiest possible installation. Pulled out the old one, undid the quick-connect hard-wire, and replace with the new one. Easy. Works well. No more constant beeping. Came with a base plate but I didn't need them since I was using the old already install plates.

I thought the alarm was self contained at first and would not work as a replacement. Then I noticed the outside was a dust cover. I am calling it out because it seems that many people have made that mistake as I almost did.

I purchased 8 (2-4 packs) of these back in Nov 2021 for $198. These were allegedly manufactured in Oct 2020 and were expected to last until 2030. 3 of the 8 have failed after less than 3 years with the tell tale sign of failure of constant chirping. I fully expect all to fail soon. These were wired in and not on battery. I clicked the item to see the current price. WOW! $500 now for a 4-pack. Stay away from this garbage. I'll just pay more at the local hardware store for something reliable.