Everyone checks that their alarms are working don't they? I thought we did but when I checked today only 2 of the 7 smoke alarms we have in the house actually bleeped when the button was pressed. It also set me thinking about the CO sensors we have. Apparently only about 45% of all sensors actually work even though the sounder does beep when the test button is pressed. CO sensors have a life of about 5 years so it's easy to believe it is working when the actual sensor itself doesn't actually work. So, lots of batteries to be bought today and I've ordered a CO sensor kit (detectagas) too. Anyone else not tested their sensors?