Security & Fire Protection Systems/USI electric smoke alarm 1204


Dave, have several model #1204 smoke alarms that began chirping, replaced batteries and still chirp about 4x/minute.  Removed smoke alarms, Briefly made reconnection to house wires and they immediately began chirping without any installed batteries.  Disconnected smoke alarm and units I assume were energized by that brief connection because they continued chirping.  Need your advise.  Units were MFG in july 2002.  Thanks, Mike

Hello Mike, and thanks for your question.

Manufacturers and industry experts say that the useful life of smoke detectors is about ten years. Yours are 13 years old.

Now, detectors often perform well past that ten-year window, but once they do have performance issues, the best advice is to replace them.

I took a quick look at the USI-1204 online, and was surprised to see that it's still an active model, and pretty inexpensive. Here's a link:

The advantage of replacing with the same model is that you'll likely be able to use the existing installed base, so it'd be a matter of removing the old and replacing with the new ... no wiring to do. Worst case, if there were changes to the model, you'd have to replace the base too.

I hope this helps!

Best Regards,


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Dave Neuweiler


The design and application of burglary and fire systems for homes and businesses. Helping alarm owners understand how their system works. Helping to troubleshoot false alarm problems. Questions about monitoring issues.


Over a quarter century in the industry. Experience in installation, service, and monitoring centers. Training manager for a national protective services company; director of education and training for a national trade organization for for alarm dealers.


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