showering? Cooking? 6-12 times a day? They must be the cleanest and most inept cooks around. Thanks. You could very well be correct, but still I'm not so sure.

It went of again at 4:45 am this morning.

I have wondered that they might be smoking in their suite. But there is no smell from beneath the door (none of burnt food either for that matter). They are fairly new tenants too and this never happened with the other guy.

Some detectors are triggered by heat and steam (you are correct on this point). Um... could they be growing something?