My wet carbon monoxide detector just went off.

June 3, 2007 7:27 PM

My carbon monoxide detector was just going off. My roommate left it on the window sill, and it got a bit wet from the rain coming in from the open window. Should I be worried, or is it just a malfunction from some water?

I am not really sleepy, but it's near my bedtime. My cats are roaming around, and do not seem any sleepier than usual. My windows are open and were open when the detector went off (there's a nice draft in here). Please reassure me that it's just the water. This is a battery operated carbon monoxide detector.

posted by hooray to health & fitness (15 comments total)

I can't think of any reason why anything other than CO would set off a CO detector, although I am not an expert and have no special knowledge.

But I would really not take any chances with this -- ignoring your carbon monoxide detector seems to me like a really bad idea.
posted by jennyjenny at 7:33 PM on June 3, 2007

I agree with jenny, you shouldn't really ignore that. If it got wet, consider it non-functional. You need to get a new detector ASAP. You might consider a detector with an indicator of the carbon dioxide level like this one. If a new detector goes off, call the fire department.
posted by tarthur at 7:48 PM on June 3, 2007

Sure, get a new one tomorrow. But is there anywhere you can sleep tonight so that you don't have to go to bed in a house where the detector has gone off? (I've lost someone to carbon monoxide, so I'm erring on the side of caution.)

If you do decide to stay there, if you get a headache or feel a little weird, then get out and call someone for help.
posted by jennyjenny at 8:00 PM on June 3, 2007

Just so you're aware, there are other symptoms that a person with carbon monoxide poisoning commonly experiences: headaches, dizziness and nausea.

I imagine it's anybody's guess as to whether water damage could cause the detector to malfunction. If you're really worried you can call your local fire department (through 9-1-1 or through the department's non-emergency number), and they will send a couple of people out with some super-sensitive detectors that can tell you whether there's any actual danger or not.
posted by TBoneMcCool at 8:02 PM on June 3, 2007

is there a 24-hour walmart or whatever near you where you could pick another one up? i am sure it is just because it got wet, but better safe than sorry.
posted by thinkingwoman at 8:02 PM on June 3, 2007

If you can leave your windows open it's unlikely that sufficient CO could accumulate.

I would check all possible sources of gas, but I suspect it's just that the damp from the rain closed/shorted a circuit somewhere inside the detector.

Try drying the thing out -- open it up to the extent possible, remove the batteries, shake out any water, put it someplace warm and dry (maybe on top of your TV or stereo), and put the batteries back in half an hour or so.

If you can't get a replacement detector tonight, you could call 911. But a detector on a windowsill going off is exposed to outdoor air, so you would expect very low probability of it being triggered. I've heard of them being triggered on ozone alert days, but usually when they're inside, where ozone can accumulate.
posted by dhartung at 8:36 PM on June 3, 2007

You could always call your local fire dept. or the non-emergency police line (311 in the U.S.).
If anyone is going to give you a good answer, it will be one of those folks.
posted by Cat Pie Hurts at 8:45 PM on June 3, 2007

Totally missed TBoneMcCool's advice...oops.
posted by Cat Pie Hurts at 8:46 PM on June 3, 2007

dhartung's got it right--for the detector to be near an open window and go off for real, your place would have to be overflowing with CO. I don't mean to diminish your concerns, and it definitely would be good to find a replacement quickly, but to my understanding, CO generally has to build up within an enclosed space. Open windows make it much less likely to be a genuine threat in your circumstances.
posted by LairBob at 9:01 PM on June 3, 2007

Thanks for your answers, everyone. I went down to my neighbor's place to borrow their carbon monoxide detector. Unfortunately, they don't know where their unit is (they are going to buy a new one tomorrow). So, then I waited 20 minutes for my CO detector to dry out, and put the batteries back in and it still went off. I called my local fire department, explained the situation and asked if they could send a guy over to check.

They sent TWO trucks in less than two minutes! A fireman came up and told me it was old or bad batteries. This was his fourth such call tonight, and that it's better to be safe than sorry.

I'll be getting new batteries tomorrow. Thanks again, mefites!
posted by hooray at 9:29 PM on June 3, 2007

I had this happen to a detector a while back. I still had the manual at the time and it told me the detector should be considered non functional and should be replaced.

If I were you I'd just keep my windows open tonight and replace the detector in the morning
posted by subtle_squid at 9:30 PM on June 3, 2007

Use a hair dryer to dry out the detector. I'm not going to touch the question of whether it is reliable after being dried or not..
posted by Chuckles at 12:02 AM on June 4, 2007

Hmm... Is there a way to test a detector with a real CO source? Light a match under it?
posted by joecacti at 5:02 AM on June 4, 2007

We had a CO detector that was never the same after the room was painted. Something about the paint fumes messed it up.
This kind of detector had a replaceable detector module, and we just replaced the module, not the whole thing.
posted by MtDewd at 6:40 AM on June 4, 2007

My CO detector went off because of a car that was idling close by for a few minutes. This vehicle was obviously having some some technical difficulties under the hood as it never happened before or since.

It doesn't always need to be something dramatic, CO detectors are very sensitive. Always be on the safe side and check though!
posted by Grensgeval at 12:34 PM on June 4, 2007