A. Within 15 feet of a fire hydrant or fire station driveway.B. On a marked or unmarked crosswalk.C. Within 3 feet of a sidewalk ramp for the disabled.D. All of the above.
Buy a new one. They are cheap. Your detector needs to work properly. Sounds like the one you have needs to be tossed.
If you think buying all those things are going to protect then, your wrong. First of all how old is the house? If it was built prior to 1975 it could have lead in the paint etc, and or asbestos. Your ignorance can not only kill you, your nephew and evey body who lives in each of yours homes.
Is it hard-wired? You will need to remove it to find out the answer. If so, then is it tied to other S/D's? If so then it could be notification of problems with system or another detector. Or you could just have a bad battery. Just because it's new, doesn't mean it's good.
