CO alarms.

They say to replace your CO alarms every 5 or 10 years. Why? If they still test OK, why replace them? Bill B.

Test them with a cigarette

The sensors are not as sensitive after time, due to many factors including dirt grease etc...

ChrisGW

Greetings,

If the company that makes the alarm tells you to replace it after five or ten years they only have to charge you for that many years of liability in the purchase price.

Hope this helps, William

imho:

I was told in my nfpa based training every 10, since a decade passing brings new 'features' in the new products, and circuitry isn't tested to last beyond a decade of use.

Might be a UL issue.

hth,

tom @

Easy...and the makers will tellyou this as well.

The sensor loses sensitivity. They also lose sensitivity if they have been exposed to a large amount of CO,or even CO2.

The better ones, will simply shut off and will not work after the internal 5 year timer is up. The ones I use, do this. They have an end of life alarm, and state this clearly in the paperwork.

The sensors become less sensitive and the test button does not test this.

You are testing the battery circuit.

The why bother with a CO detector at all, if it is in a work bench drawer? For a CO detector to be useful it needs to be in an area with a natural airflow. A drawer would not seem to qualify.

I suppose you could be working occasionally with a forge, or gas fired kiln or some such thing, and then take it out only when you need it. However, workshop environments are not usually pristine, and I would think it would still be prudent to change it out after the expiration date.

Gary Dyrkacz snipped-for-privacy@comcast.net Radio Control Aircraft/Paintball Physics/Paintball for 40+

Subject: Re: CO alarms. Newsgroup: alt.home.repair => Nick Hull Test them with a cigarette

No. That is not an approved testing method.

Ok, I can agree on the test button. But mine goes through about 3 minutes of self test on powerup. Is this a sufficient test?

Bob S.

Subject: Re: CO alarms. Newsgroup: alt.home.repair => George E. Cawthon But many old smoke

The bottom line is, the NFPA recommends replacing any smoke detector every ten years. Unless you have the equipment to test the sensitivity of the unit, you can NOT be sure it is functioning correctly. In fact, for commercial applications - they MUST be tested for sensitivity range every year, or be replaced.

All you cheap bastards:

Replace your smokes if they are over 10 years old.

That sounds almost like an old safety NCO that said a knot in an electrical cord was bad because the electrons had to speed around the corners and that made the wire hot.

Apparently your instructors fall into the same category. I would be very leery of any of their personal descriptions of how things work.

Some sensors have a limited lifetime. But many old smoke detectors are based on a light sensor and there is no reason that the circuit wouldn't last for decades. My original smoke detector still works after nearly 30 years. I've got another 10 year old smoke detector (ionization type) which is still so sensitive it goes off every time somebody make toast.

Not approved but ti sure checks to see if the unit is responding.

Subject: Re: CO alarms. Newsgroup: alt.home.repair => Nick Hull > No. That is not an approved testing method.

Not an accurate test et all. Just "responding" aint gonna cut it.

We just bought a replacement for in some rental property. The label says the limited warranty expires in 5 years, but nothing about the functionality of the smoke/CO detector itself.