Livre d'Or

A smoke alarm sounding intermittently *may* be because the batteries need to be replaced, so it may be worthwhile trying new batteries in the alarm to see if you still get it sounding occasionally. [I hate replacing smoke alarm batteries, because adding the last battery makes the alarm beep loudly. The best I can come up with is burying the face of the alarm in a towel.]

Hope day time has allowed you to have a good look around the house to reassure yourself there's nothing smoldering and that you get a full night's sleep tonight and getting the gas/boiler reconnected is straight forward.