I have two smoke detectors. Good batteries and when I push the test button the alarm works. But I just filled the house with smoke from an unwatched pot on the stove. Neither smoke detector alarmed.

I assume they are defective. But how common is this? And if the test button doesn't reliably indicate they are working, how do you check them?

Thanks,
Walt

I haven't had a problem with one that doesn't work with good batteries installed.
The way I check mine is to hold a lit match near them, by standing on a chair
And holding it as close as possible without touching the plastic. As soon as
There is any smoke from the match, the detectors start to sound. (Be careful
Not to drop the match)

If u smoke, blow smoke from cigarette in it.

Chuck

Here is a proper way to test:

SM-200 - Smoke! In A Can Smoke Detector Test Spray - Home Security Store

There are two kinds of smoke and two kinds of smoke detectors.

Photoelectric detectors will go off from dust or steam.

Ionization type detectors have a small amount of a radioactive element in them. It will only detect something actually burning. These have disposal instructions on them as well.