Security & Fire Protection Systems/Smoke alarm


What causes a smoke alarm to go off  even when a new battery has been installed?

Hello Nancy, and thanks for your question.

I'm assuming that after you changed the battery, that the smoke detector is chirping (low battery signal)as opposed to alarming (detection of smoke).

Oftentimes, the smoke alarm retains memory of its previous state, and after signaling a low battery, it will continue to do so even after a new battery has been installed.

To cure this, you must reset the detector. This is done by removing all power -- that's AC power if it's there, and removing the backup battery. Once this is done, press and hold the test button on the detector for a count of ten. Re-install the battery and the AC power.

The detector should now function normally, with no chirping.

On the chance that this does not cure the problem, the detector should be replaced.

Let me know if you have any trouble with this, and I'' try to help you get through it.

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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