I got a call about a fire alarm system constantly sounding. There is nothing that indicates an actual alarm unless they are resetting it. The apt. building is unoccupied.
The system was installed 10yrs ago.
It is a Firelite 4 zone panel.
What could be some causes?

I once had water flow alarms that turned out to air bubbles in the system.
dust in a smoke will cause false alarms.
You will need to know if the panel is being reset thus cleared of what zone the trouble is on. Chasing a ghost in a F/A can be "fun"
Is it an addressable system ? If so the panel will tell you what device set it off.
Keep us posted on this

Look for roaches in the smoke detectors. If the building is unoccupied there could be some unwanted guests. I have worked in some lowcost houseing projects and found roaches in detectors. A good indication is that it is always the same zone or zones.

Watch out for rodents chewing on wires or doing thier business on devices, that'll do it too...

I guess that is why the owner asked me if rodents could be the cause.

Another problem could be a roof leak causing a device to short, or excessive humidity could be causing a smoke detector to trip. I've seen both cause a nuisance alarm.

Peter

I've had several locations where construction dust or moisture have caused photoelectrics to go into alarm. These should latch the zone though. Many times I'm told that the fire alarm is going off when it is really the trouble audible, which doesn't need acknowleged to clear in many systems.
Joe

Assuming this is a non-addressable system?

Unnoccupied building? Wafting dust bunnies? What kind of general condition is it in? Intermitant power and dead back-up batteries?

A good place to start would be tech support....

Otherwise, I think DUST.

Most manufacturers recommend that smoke detectors be replaced every 10 years.

Peter

[This message has been edited by CTwireman (edited 03-21-2006).]