Failure to test detectors leaves completely inoperative detectors on walls and ceilings, where they remain.
The primary problems are batteries, wiring harnesses, vandalized detectors and age. Having found and replaced 100’s of fully inoperative and misplaced detectors, I may not yet have saved a life, but I certainly made lives more secure, and performed valuable education on the topic of proper alarm use to the various concerned parties. Except on this forum, feedback has been universally positive for this aspect of my service package. I’ll take the real world over this forum every day.
Pushing a button tests important parts of the alarm. Field testing with smoke is not a calibrated operation, but tests more of the alarm.
On the commercial side field testing is 100% possible and done for sensitivity.
Calibration is not my goal or problem: proper placement and operation to the local fire code of certified units is.
Go ahead and leave completely inoperative smoke detectors in homes.
I disagree with that as a standard of practice, and will not change that practice with a cogent argument for how I’m harming my clients and the future residents of the buildings.
The nice thing about being self employed is that You can operate your business as you see fit. I never wanted to accept the liability of running around and testing all of the smoke detectors in a home and i think we can all agree that pushing the button only tells You whether it beeps or not. I personally believe that good working alarms are the cheapest insurance anyone can buy and as such all of my inspection reports ended with…I recommend the replacement of all smoke alarms and the addition of carbon monoxide detectors prior to move in.
@bnesbitt has a number of these threads which tout his smoke alarm testing abilities. In each I have responded by indicating all you really need to do is assure proper installation and date (less than ten years old.) My reports always indicate the reasoning and safety needs of current smoke and co alarms. It is such a common situation that I have a report attachment for it. This is what the newcomer needs to know, not how to get themselves in legal trouble as Bryce suggests.