Quizland

Things that set off my upstairs smoke alarm  :scratchhead

Having a Shower or Bath
Using the grill downstairs
Boiling anything on the hob in the Kitchen downstairs
Pancakes
Painting the Bathroom ceiling (Today's reason?)  ::)

Fire or Smoke .. possibly??
Did set fire to chip pan a few years ago, not a peep from smoke alarm

Sounds to me like you need a new one  :yes

This was the new one, which reacts much the same as the old one.  ::)

Replaced after the old one refused to turn off after (a reason I forgot to mention) using the tumble dryer.
Removed battery and left outside in fresh air, but as soon as battery put back it went off again even a couple of days later  :headwall

Is it a multi alarm that also does heat, smoke and maybe carbon monoxide (CO)? If it has CO then maybe you have an issue somewhere with an appliance that's giving out small amounts of CO.

No, supposed to just be a smoke alarm
Although it appears to work best as a steam alarm  ::)

Picture, the old one that still won't stop beeping every time you put the battery in
(and yes I have just noticed it should have been replaced 7 years ago)
SA.JPG

Relocate the smoke alarm.  That's what I had to do.  I live in an apartment.  The original smoke alarm was located just outside the bedroom door.  I bought a new one for the kitchen.
Apparently in the good old days they were more concerned with smoking in bed.

They come in and test the alarms twice a year.

I remember a sign in a motel.
"Don't smoke in bed.  The ashes that fall may be your own."

Read the instructions that come with the unit.  I didn't realize you should vacuum the unit on a regular basis.