fire alarm system

I doubt that the whole system would need replaced. Read the manual for your particular system. At most I would replace the smole detectors. Smoke detectors can build up dust and debris inside them.

Hank

Typically the recommendation is for the heads themselves, as they can degrade with age, especially the ionization type ones as they rely on a small amount of radioactive material (Americium if I am not mistaken.) But whether or not to replace the rest of the system really depends on whether it is obsolete or not, e.g. if a component were to fail, would you be able to buy replacement parts quickly and easily?

Sadly, this is kind of a weasel answer, but my response is "it depends

- ask your dealer."

Finally, keep in mind that current code likely requires more than four detectors unless you have a very small house, and also would require that those detectors be hardwired with battery backup and interconnected. Don't quote me on this because I'm going off memory (in other words, do your research) but I believe that you are required to have at a minimum one detector per floor, and then also one immediately outside and one inside each sleeping room. Basically you would rough in an octagon box at each location, and connect them all with 14/3 (or 12/3 if you are using a 20A circuit) and then at the location closest to your panel - I'm ASSuming that this is really a residential security panel with FA capabilities - use a detector in that location only with a relay base and tie the relay contact to a hardwired zone on your panel and program that zone for "fire alarm." (the last part is not required by code, but you might as well use the capabilities of your system.) You don't *have* to do this - in most places there is no requirement to bring an existing structure up to current code unless you're remodeling - but I'm just throwing it out there because it might prove to be a selling feature down the road.

good luck,

nate

Agree. It's the smoke and any carbon monoxide detectors that need to be replaced about every 10 years. The reliability of the rest of it is dependent on what system you actually have. For example, many home security systems that include wireless have a feature where if the main console with the receiver hasn't heard from a sensor in some period, like the last day or two, it will issue an alert. It also monitors for low batteries in the wireless units. If your fire system has those feature then you can be more secure knowing there is some level of supervision. If it doesn't, then I would not rely on it.

Carbon monoxide detectors have a finite lifetime - maybe 5 years.

I've got a smoke detector that must be 20 years old and still works - my wife occasionally checks it by not adequately venting her cooking;)

Even in a clean environment smoke detectors have a limited lifespan

I agree.

I haven't figured out how smoke detectors fail. You can blow dust out of photoelectric ones. Americium in ionization types has a half life of over 400 years.

I think it's one of those erring on the side of caution things. They're not expensive, and the consequences of one not working when you need it to aren't particularly pleasant. I imagine that it's more that 10 years or so is all the designers expect them to be in service, so nobody wants to go on record as stating that they will still work acceptably after that time period.

nate