I just realized that one of my smoke detectors has probably not had its battery replaced for a very long time. When I went to separate the face plate from the base that attaches to the ceiling I could not do it. I could not see or feel any tabs. The unit seems to be hanging from the ceiling by one screw. I don’t want to force anything. This unit has been in place for years.

So, if there is one site that provides manuals and pictures for many different brands I might be able to solve the problem or if anybody wants to e-mail me, I could take a picture of the unit so somebody might be able to identify the brand and I could go from there. I suppose I could try to pull the screw out of the ceiling but I really don’t want to do that if I don’t have to.

Usually, you push on the detector ever so slightly and then twist counterclockwise to remove it from the mounting plate. Some units that are hardwired electric (ac) with a battery back-up have a swing open door on them that you access the battery with. Some are on the face of the unit and some swing out from the side of the unit.

If you are not sure of the age of the detector, you may want to go ahead and replace it; many of the detectors on the market today have a lifespan of 10 years. if you have a heat source that uses combustion, such as a gas or oil furnace, gas logs, stove or water heater, consider replacing the detector with a
combination smoke and CO2 detector. these are available at most hardware stores and considering what they do for you, are very inexpensive. new dwelling units have to have a smoke detector in each bedroom, one outside each sleeping area, and one on each level near the staircase. if the residence has a combustible heat source, as mentioned above, a CO2 detector is also required by code and all detectors have to be connected so they all sound when smoke is detected.

Google free manuals smoke detector. It is probable that your SD is powered by house current. Mine is.