Mains powered smoke alarm with a 9v capacitor backup ‘battery’.
I can remove the unit from the ceiling and I can see a power cable connecting to the unit. I’m assuming I can just unclip the unit from the roof?
Once that is done, any idea how I replace the capacitor?
Last time I tried I ended up shocking myself as the capacitor discharged itself (was a disposable camera flash!) so apart from not getting the unit dismantled to see how to remove the battery, I’ve no idea what I’m going to have to replace.
Any tips?
Thanks.

Either you had alot of power cuts or that smoke alarm is now out of date.

They are only designed for 10 years after that the source that allows smoke detection is less effective.

Replace the whole thing. It’s only £30 at the most and if you can’t afford that I have one sitting in a box that you can have.

But if mains powered it’s likely interlinked. Also, be wary when disconnecting as they can draw power from lighting circuits.

Thanks, will order a new one.

They are only designed for 10 years after that the source that allows smoke detection is less effective

Unless you have the first batch of free ones we were handing out, they only lasted a week if yoù were lucky.

Must change mains detectors soon 18 yrs old now….

it depends on the brand, some are just ones you throw away once their time is up. Some have replaceable batteries, in general you can just pull out the connector from the back of the unit, then there will be a compartment with the battery inside. You may have to remove a screw. If you want to post a photo, ill tell you what you need to do.