An irritating beeping noise early in the morning is bad enough but on the morning that the clocks have gone forward it's an hour worse.

That Sunday at 05.00 GMT my smoke alarm started to beep, but not to protect me from death by burning. There was no cloud of smoke. There was not so much as a wisp in evidence.

Once the brain had cranked into gear I decided that the backup battery (it's a mains connected gadget) was exhausted. I got up on a chair and struggled with the cover while generating a major crick in the neck. It was only an hour or so later once Connor had been roused that I remembered I had a step-ladder, well two actually.

No way could I see how to get it open to get at the battery and stop the infernal beep.

We discussed breaking it apart with a sledgehammer. I'll wait until I can inspect some like it to try to work out how to open it up. It doesn't seem to have the same mechanism as the ones I installed in Mountcastle. Fortunately I was out a lot that day.

On Monday I unsuccessfully looked for a similar alarm but mercy me it didn't beep until just before the electrical shops closed at 5pm. It beeped all night.

Tuesday morning it got too much for me and I started to dismantle the beast and at an early stage snipped some wires to give blissful silence. Once in pieces it was clear how it fitted together.

The next challenge was to find exactly the same model so that the base plate still attached to the mains didn't need to be removed. A combination of internet search and telephone enquiry led me to one in Abbeyhill and in a jiffy all was fixed.