CO detectors - chirp chirp chirp!!

[Rohan]

My boat has 3 CO detectors that came factory delivered in 2006. One of them starts chirping every day. I press the reset button, and it is fine until the next day. I know it's not a CO problem because I haven't even been running the engine. No one around me has either, nor has anyone been running generators or anything like that. I come back to my boat at the marina the next day and it's going off again. Of course, the first thought is that the battery is low but these don't use their own batteries. They are hard wired into the boat and there is no switch that controls them, and no way to turn them off other than disconnecting the main battery bank. And my 12 volt batteries are fine, I checked them. In fact, I recently replaced half of them.

This is just annoying, but the other day another detector was in alarm mode when I arrived. It wouldn't stop alarming no matter what I did, so finally had to resort to cutting the wire, then re-joining it. And it was back to normal. They are Costar model detectors exactly like this: https://www.jmac.com/Quantum_Group_1...-12-24SIR.htm=

I have opened them up, cleaned out any dust, but still the problem persists. I could buy separate battery powered ones and use those instead but since the internal wiring already exists, I would rather use what I have.

Any suggestions? And do CO detectors normally lose their ability over time?

[rslifkin]

CO detectors only have about a 10 year lifespan. So I'd say yours are probably dying and it's time for new ones.

[Seymore]

I installed a CO detector into my 32' sailboat a few years ago. It went off at 3 am about three times a week, and I finally chucked it.

[BlackHeron]

Batteries charging can set off a CO detector, especially when it is really hot. Cheaper home units installed in boats are especially sensitive to this whereas as marine-specific detector will be better at rejecting false alarms like that. I've got a box full of $30 home units that I went through before finally digging deep into the cruising kitty to buy a fancy direct-wire 12v marine unit for $150. No more false alarms. It's only 2 years old at this point and will probably fail in another 6-7 years as that's all they last.

[fox9988]

Originally Posted by rslifkin

CO detectors only have about a 10 year lifespan. So I'd say yours are probably dying and it's time for new ones.

This^. There should be a sticker on it with a date.

[BlackHeron]

Because many units are already years old sitting on the shelf. If it was easy to see how much life was left in it nobody would buy the one or two year old ones that sat too long.

[IslandHopper]

Originally Posted by fox9988

This^. There should be a sticker on it with a date.

Originally Posted by rslifkin

CO detectors only have about a 10 year lifespan. So I'd say yours are probably dying and it's time for new ones.

I think a clue is in the link provided....

https://www.jmac.com/Quantum_Group_1...-12-24SIR.htm=

"Backed by a six-year limited warranty"

They are now at least 14 years old, replace them and sleep easier......

[Cpt Pat]

Originally Posted by Seymore

I installed a CO detector into my 32' sailboat a few years ago. It went off at 3 am about three times a week, and I finally chucked it.

I had the same experience. "Marine CO detector" fresh from the factory. It cost $90. Got a second one on warranty. Factory direct. Same behavior. 4 AM: BEEP! BEEP! BEEP! BEEP! "Wake up stupid! I need attention!" I sent both back to the factory on RMA. After weeks: crickets.

Then I bought a cheap one on Amazon, and it works fine.

The CO2 (that's carbon DIOXIDE) level in my cabin rises to 2,000 PPM at night while I'm sleeping aboard. I have a CO2 monitor. I suspect that was the cause of he false alarms.

[GILow]

Sounds like they are too old, but I've also discovered first hand that batteries being charged can trigger them and epoxy curing will also set them off.

[sailorboy1]

the thing is

you don't really know if the one chirping is the bad one or if the one that isn't is the bad one

[garychurch]

My hard wired CO detectors did the same thing, all of them almost in unison. Found out the radium in these were depleted after 5 years. Bought new ones with a 7 year radium lifespan.

[garychurch]

There is a difference between CO (carbon monoxide detectors) and CO2 (carbon dioxide detectors).

[a64pilot]

Originally Posted by Cpt Pat

The CO2 (that's carbon DIOXIDE) level in my cabin rises to 2,000 PPM at night while I'm sleeping aboard. I have a CO2 monitor. I suspect that was the cause of he false alarms.

How do you monitor it, which monitor and curiously, why? Assuming your correct you really ought to ventilate your sleeping compt, that’s about five times what outdoor air should be, and OSHA has set a max of 5,000 PPM for an eight hour work day.

[a64pilot]

Originally Posted by garychurch

There is a difference between CO (carbon monoxide detectors) and CO2 (carbon dioxide detectors).

Yes there is of course, but very often, especially the less expensive not lab quality detectors will also detect and alarm from other gasses, like hydrogen from battery charging for instance, so it’s very possible if not likely that an inexpensive consumer CO detector could alarm on CO2.
Often testing standards don’t test for false alarms, they are only interested if it alarms at the correct level of the gas it’s being tested for.

[AlanT]

I had exactly the OP's same problem with hard wired CO detectors in one of my rental apartments. Detectors were around 10 years old, had hardwire and batteries. After ensuring any possible CO sources were eliminated from consideration we eventually cut them out and replaced with new battery operated ones. This was a solution and makes me think that the chirping is some sort of pre-failure warning.