Carbon Monoxide alarm activation......

[Tim O]

Ok so the other night the CO alarm in the saloon went off at 1:30 in the morning...(strangely after I had performed the first"test" of the sounder for months - yes I know, should be done weekly)

Its an alarm that doesn't meet the standard for Boats by the way and its been in use for about 4 years.

We pondered the situation....there was nothing that could be a source of CO running (engine, Eberspacher, cooker are the only ones on board) nor had there been for days with the exception of the cooker. Because of the fine whether we had had hatches open for hours every day for about the last week...so I figure the boat was pretty well ventilated

I removed the battery and put it back in and tested the sounder again figuring if there WAS CO present it would go off again...it didn't

We opened up all the hatches and went back to sleep

I then went out and bought 2 more Fire Angel ones which are certified for boats and put them in both cabins.

Neither of those has sounded. Yesterday the original one sounded again in the saloon.....I immediately swapped one of the new ones into exactly the same place - that has NOT gone off. I removed/replaced battery in first one....it has not gone off since.

As before there have been NO souces of CO running except the cooker for maybe 10 minutes each morning and 45 each evening, with hatches open for ventilation while I'm using it

I'm well aware of the dangers of CO, but by my reasoning if two out of 3 detectors are not showing a problem then maybe its because there isnt one and its a faulty detector

Can these things develop a fault....or respond to something that isn't CO? Or should I abandon ship?

Id like to buy one of the ones that actually shows CO concentration...any reccommendations?

 

[Irish Rover]

I bought and installed 2 x Kidde 7DCO from Amazon a couple of months ago. Both constantly reading zero which is great except you then start to wonder are the really working.

 

[cindersailor]

Is it possible that it is sounding to indicate that the battery needs replacing? I know some smoke detectors do this.

 

[bitbaltic]

Check your (12v boat) batteries are not gassing slightly. Hydrogen will also set off CO alarms.

 

[Tim O]

Now that might be the answer...the only other thing that I have recently changed on the boat - literally a week ago - is to install a CtEk M300 charger wired direct to the domestic battery bank......It was running and had been for a few hours at the time of both alarm activations...the alarm was situated just outside the cupboard that houses the batteries, which has a vent grille.

I did wonder this myself at the time and felt the batteries with my hand - they were "warm" to the touch, not hot but warm, and I could hear a very faint noise from them.

If they are gassing....is that bad? Should I do something?

 

[VicS]

Ok so the other night the CO alarm in the saloon went off at 1:30 in the morning...(strangely after I had performed the first"test" of the sounder for months - yes I know, should be done weekly)

Its an alarm that doesn't meet the standard for Boats by the way and its been in use for about 4 years.

We pondered the situation....there was nothing that could be a source of CO running (engine, Eberspacher, cooker are the only ones on board) nor had there been for days with the exception of the cooker. Because of the fine whether we had had hatches open for hours every day for about the last week...so I figure the boat was pretty well ventilated

I removed the battery and put it back in and tested the sounder again figuring if there WAS CO present it would go off again...it didn't

We opened up all the hatches and went back to sleep

I then went out and bought 2 more Fire Angel ones which are certified for boats and put them in both cabins.

Neither of those has sounded. Yesterday the original one sounded again in the saloon.....I immediately swapped one of the new ones into exactly the same place - that has NOT gone off. I removed/replaced battery in first one....it has not gone off since.

As before there have been NO souces of CO running except the cooker for maybe 10 minutes each morning and 45 each evening, with hatches open for ventilation while I'm using it

I'm well aware of the dangers of CO, but by my reasoning if two out of 3 detectors are not showing a problem then maybe its because there isnt one and its a faulty detector

Can these things develop a fault....or respond to something that isn't CO? Or should I abandon ship?

Id like to buy one of the ones that actually shows CO concentration...any reccommendations?

I have a Fire Angel one that shows CO concentrations but the novelty of regularly reading zero soon wore off ! Not worth paying the extra IMO.

They are cross sensitive, but not normally to other gasses found in the home. In the boat response to hydrogen from ( over)charging batteries is the most likely as already pointed out.

They are designed to emulate the cumulative effects of CO on the body. The alarm point is a combination of CO concentration and time. The lower the CO level the longer it takes to alarm, the higher the level the quicker it responds. The instructions should say the concentration that will cause an immediate alarm.

I'd say you probably have a dodgy one. It could have suffered from the effects of vibration etc on the cell if it is one intended for static use only. Not worth messing with.

 

[PaulRainbow]

Now that might be the answer...the only other thing that I have recently changed on the boat - literally a week ago - is to install a CtEk M300 charger wired direct to the domestic battery bank......It was running and had been for a few hours at the time of both alarm activations...the alarm was situated just outside the cupboard that houses the batteries, which has a vent grille.

I did wonder this myself at the time and felt the batteries with my hand - they were "warm" to the touch, not hot but warm, and I could hear a very faint noise from them.

If they are gassing....is that bad? Should I do something?

I wouldn't expect the batteries, under normal use/charging to set the Co alarm off, they should not be gassing that much. Certainly wouldn't expect to be able to hear them bubbling. Check the charger setting and keep an eye on the batteries, a failing battery sometimes gasses excessively. You may have one battery with a dead cell, so worth checking them individually.

 

[mlines]

The CO sensors in these units have a "life". On older units they just ungracefully fail at the end of their life , spurious alarms etc. On newer devices the manufacturer kills the device at a pre-programmed age and sounds an alarm beep all the time. We just replaced an inbuilt one on our boat at 9 years old, it was spuriously sounding when no possible source of CO around.

 

[Giblets]

If it's four years old the sensor will be approaching end of life so this could be the cause of the activation.

 

[VicS]

If it's four years old the sensor will be approaching end of life so this could be the cause of the activation.

Depends. Mine has guaranteed life of 7 years. Some are 10 years .

 

[Tim O]

I wouldn't expect the batteries, under normal use/charging to set the Co alarm off, they should not be gassing that much. Certainly wouldn't expect to be able to hear them bubbling. Check the charger setting and keep an eye on the batteries, a failing battery sometimes gasses excessively. You may have one battery with a dead cell, so worth checking them individually.

Hi Paul - I was running the charger either on its "normal" setting or the quieter "night" setting..i thought the point of these super-expensive smart chargers was that they couldnt overcharge the battery?

How would I go about checking battery cells individually...what am I looking for?

While I am at it...should I ever have been doing anything with fluid levels in batteries...Ive never done anything as I thought modern batteries were "maintenance free"?

As you can tell, I know sweet FA about batteries!

 

[bitbaltic]

I wouldn't expect the batteries, under normal use/charging to set the Co alarm off, they should not be gassing that much.

Neither would I, but the last time I mentioned it here in connection with CO, some old boy or other toddled along to opine that batteries are not charging properly if they are not gassing enough to set off CO alarms. That’s YBW I guess!

 

[sarabande]

Tim

I think the Cetrek (which is the same as mine) has a tiny fan, which is almost whisper quiet one. Hence the 'Night' setting. When I first got it, I thought the charger was playing havoc with gassing.

If your batteries have only two terminals, and no access via screw plugs to the cells, you can only check the battery by a 'drop test'.

https://duckduckgo.com/?q=battery+drop+test&t=ffab&atb=v69-7&ia=web

You only need to go through the palaver of density testing and topping up if your batteries have individual cell plugs. Other wise, leave well alone.

If you have multiple domestic batteries, it makes sense to be able to isolate one of them by means of a heavy duty terminal switch.

https://www.ebay.co.uk/sch/i.html?_...ch.TRS0&_nkw=battery+terminal+switch&_sacat=0

Used with diligence, this ensures that you have one battery nearly full state, just in case something goes wrong with the others. A set of jump leads is also useful to save disconnecting and reconnecting. Usual caveats about always having one battery in the charging circuitry to prevent the alternator committing hari kiri.

 

[GHA]

My CO Kidde alarm will go off with the batteries in absorption @ 14.8v for a while. Also gets set off if using a gas soldering iron for a few minutes. Sensitive things!