I have a customer that has called saying her smokes are 2 years old since the last replacement.they work for about the 2 years and then they start going off consistently. The Home was built in 2001 . The smokes are hardwired and the brand is kidde.... There wasnt any problems during the 2 years until now. These are not battery back up. any ideas I am sure she will want to replace them again but She figures they should last more than 2 years. We are in a dry climate .
She has turned off the circuit for the smokes and has 2 small children It is a higher end type home.

Doug,
At the very least I would check the circuit that connects the smoke detectors together and the circuit that it is powered from.
It sounds to me that the detectors aren't too happy with the supply voltage they are getting and are doing a slow burn.
To turn off the circuit, is just stupidity, you might as well not have them at all.
Maybe it could be a manufacturing fault with the devices, it might pay to contact the manufacturer to find out if any others of this particular model have suffered the same fate.
I would tend to hope that you would get more than 2 years out of a smoke detector.

Check if dust could be entering them from the ceiling void, driven by air currents.
This can cause failure with false alarms.

I would check to see which device is causing the alarm. We had a problem that turned out to be the location of one smoke (in the stairwell). Don't know why that location caused the smokes to go bad but we moved it 5' over and it solved the problem. I would also check the orange wire that dasiy chains the smokes together for loose connections. Good luck Rod

Are the units interlinked? I don't know Canadian code, but here they have to be.

If so, it could just be a single unit that has gone belly up, and it's causing the others to react. I would probably start with removing one at a time from the circuit and see what happens. It'll be noisy and annoying for a time, but it's likely to save a few $$ for your client.

Otherwise, I'm with Trumpy on this. 2 years would be a pretty lousy service life for a SD of any brand, and I would have a word with the manufacturer to see what they have to say about it.

Good Luck!

Yes they are Linked together code is the same here for smokes except we just need them outside of sleeping rooms not in each bedroom so a single smoke could service a hallway with 3 bedrooms.

My 1st thought, turn them on, 1 is better than none,and the $22.00 ea is worth every penny!

Do they go off at any particular time? or totaly random?
I have seen single units go bad and do this also.

are they ions or photo?(ions will have a "radio active mat" warning on the back)
If photos a good vacuume should help. If ion, most likely a bad unit. However kidde has a darn good product. so check with them.

Locations?
Ions are suseptable to air changes, steam etc, and are designed for a flash/high heat/quick change type event as well as smoke.Could they be near a register with a humidification unit?
Photos are best with smoldering types. The little light inside is very comfy for small insects.

The inter connect wire switches the neut.to the sounders.
a loose connection on any of the wires could do this.I've witnessed vibrations affect a device in the basement.

Are there heats on this circuit? I have seen the inter connect aux relay used for these fail and cause alarms.
Again, 2001, probably electronic heats, check any way.

Small water leak? anyway, get them working they do SAVE lives!

Just some thoughts, good luck

I have had that same problem only it was with a unit at the top of a basement stairway and it triggered at 2:30 am therereabouts every time.. Changing brands didn't help, changing units around didnt either.. I still do not know what the problem was, it has seemed to rectify itself!
Ghosts maybe? LOL

A.D

I had similar problem as rewire. I called Firex and they explained that when the Power co. would shut down 1 of there gen. it woyld cause spikes and noise ,usally late at night or early morning when demand was down. This would set the units off. I thought, yea right! But I was willing to play along. So, I installed a surge breaker in the panel. Guess what it worked I have not had a problem since.

Firex

I've had tons of trouble with their units.

Had an odd problem like this at the FD once (then later at my own house).

The 2nd floor smokes were fed by a conduit run that enetered the attic space and went above the insulation. It then re-entered the living area.

Seems the airflow was just enough to allow condensation to form and trickle into the back of the detector, causing them to sound for no reason. Removing the detector from the circuit (of course) enabled the other to function, and revealed evidence that it had been happening for a while (rust traces).

I've since heard of EC's using a dab of firecaulk or a shot of spray foam in the pipe entrance to prevent this occurrence.

Sounds like a band-aid fix for a bigger problem

Ya that is sometimes a problem. You would think if all the pipe runs end in a heated space and you keep the pipes at the joist level it would not happen, but it does. Used duct seal on the pipes. Also moved insulation over the EMT in the atic. Realy I think is is more of an insulation in the atic issue in most cases. Have herd the ideal solution is to have the pipes go in the side of the box not the top. Maybe that would work if you could keep the pipe at the bottom of the joist deep in the insulation. Some smokes have a gasket to prevent airflow. But it still happens. Maybe a bit of fiberglass insulation in the J-bx.

The worst is when there was a problem but have no idea which one of the 10 or so devices caused it. I wish the SD would have a resetable indicator to show if that perticular one was triped.

Just herd today FireX recall on CO detectors.

Do like me. Have the smoke hang by the wires. Then if it goes off hit it like a piñata.