Another alarm?

[Barnacle Bill]

Just been reading RYA advice to fit a CO alarm. Now I'm not a great fan of alarms - I was obliged for Cat 2 Coding to fit a smoke alarm, which went off the first time I used the cooker (even though it was mounted some distance away); and a gas alarm, which goes off if the battery voltage goes down (say in the middle of the night with the anchor light on) - and the only way you can silence it is to switch the power off, which is exactly what you shouldn't do if there's a gas leak.

Is this one different? Can it guarantee NO false positives? And am I kidding myself in thinking a) CO from the cooker is unlikely and b) I would probably smell an exhaust leak if the engine developed one?

 

[NormanS]

For all the price of a co alarm, fit one.

 

[Lon nan Gruagach]

Just been reading RYA advice to fit a CO alarm. Now I'm not a great fan of alarms - I was obliged for Cat 2 Coding to fit a smoke alarm, which went off the first time I used the cooker (even though it was mounted some distance away); and a gas alarm, which goes off if the battery voltage goes down (say in the middle of the night with the anchor light on) - and the only way you can silence it is to switch the power off, which is exactly what you shouldn't do if there's a gas leak.

Is this one different? Can it guarantee NO false positives? And am I kidding myself in thinking a) CO from the cooker is unlikely and b) I would probably smell an exhaust leak if the engine developed one?

Any flame can easily produce CO and its a killer, you wont smell a bad flame on the cooker.
If theres any consolation, you can get combined CO/smoke alarms.

 

[Sandyman]

When our smoke alarm goes off it means the wife is making toast for breakfast. Happens every time.

 

[GHA]

Is this one different? Can it guarantee NO false positives? And am I kidding myself in thinking a) CO from the cooker is unlikely and b) I would probably smell an exhaust leak if the engine developed one?

The kidde one I have goes off when the batteries are charging up at 14.8v and a load of work with a gas soldering iron will set it off as well. Very sensitive.

Which, as a liveaboard, is comforting

 

[VicS]

Just been reading RYA advice to fit a CO alarm. Now I'm not a great fan of alarms - I was obliged for Cat 2 Coding to fit a smoke alarm, which went off the first time I used the cooker (even though it was mounted some distance away); and a gas alarm, which goes off if the battery voltage goes down (say in the middle of the night with the anchor light on) - and the only way you can silence it is to switch the power off, which is exactly what you shouldn't do if there's a gas leak.

Is this one different? Can it guarantee NO false positives? And am I kidding myself in thinking a) CO from the cooker is unlikely and b) I would probably smell an exhaust leak if the engine developed one?

A CO alarm is certainly not immune to false alarms. The sensors are electrochemical devices and are cross sensitive to some other gases.

In normal circumstances the cooker should not produce CO but if anything upsets the combustion it could. People have been killed by CO poisoning from exhaust gas leaks mv Arniston on Windermere comes to mind. Also a more recent case on the Norfolk broads and another in Cardiff very recently. Presumably they did not notice the smell of exhaust gas.

 

[dunedin]

We have six kiddle CO alarms in various places - never had any false alarms (unlike the smoke detectors, none of these on boat for this reason)

 

[Cantata]

I had a CO alarm on my previous boat and it was the first thing I added to the current boat. Both Kidde alarms, the type that shows a digital reading. Not had any experience of them giving false alarms.
To the OP - I wouldn't hesitate to fit one, I've known two families lose loved ones to CO poisoning (although not on boats) and that was quite enough for me.

 

[Robin]

They have replace by date too usually, ours was 10 yrs expiry when it misbehaved, new one after several attempts still went off until I found another make which perchance had a 15yr expiry. charging batteries with a high amp smart charger set ours off as did using spray polish like 'Pledge' or using contact adhesive. I didn't think boat diesels give out CO from exhaust and the risk is from say a gas heater(not a catalytic one), gas water heater ( Ascot type thing) or the the gas cooker or dumbest of dumb a paraffin space heater. .

 

[chrishscorp]

I didn't think boat diesels give out CO from exhaust .

They give off less CO than a petrol engine but they do still give off CO and in an enclosed space enough to be fatal.

 

[prv]

I fitted one after yet another dead family in the news (can't remember which of the several incidents it was) and haven't had a false alarm. The gas alarm did once go off when I was sloshing acetone around near its sensor.

Pete

 

[Uricanejack]

A false Alarm is a minor irritant. I am happy to put up, with rather than the alternative.

My Father in Law. (retired fireman) Bugged us for years about smoke alarms. I would disconnect the one near the kitchen. As soon as he left and try and remember to reconnect before he came back.
I stopped after he was woken up late one night by the Co2 Alarm. Faulty gas central heating. He survived.

 

[Robin]

A false Alarm is a minor irritant. I am happy to put up, with rather than the alternative.

My Father in Law. (retired fireman) Bugged us for years about smoke alarms. I would disconnect the one near the kitchen. As soon as he left and try and remember to reconnect before he came back.
I stopped after he was woken up late one night by the Co2 Alarm. Faulty gas central heating. He survived.

In my case false alarms were heard by marina neighbours and reported to the office who called us to go check, so not a minor nuisance, nobody on board, no engine or stove left running, just a false alarm. it was a digital display version that remembered the highest fig it had found but not of course What caused it.

 

[Barnacle Bill]

In my case false alarms were heard by marina neighbours and reported to the office who called us to go check, so not a minor nuisance, nobody on board, no engine or stove left running, just a false alarm. it was a digital display version that remembered the highest fig it had found but not of course What caused it.

I would say false alarms are certainly a nuisance, and if repeated the alarm will probably be ignored, the way most of us now ignore car alarms. The 'boy who cried wolf' story is still with us. An alarm which gives false positives is, technically, not functioning correctly.

Overall CO deaths seem to average about 70 per year in the UK (1995 - 2015) - av 2.8 per year in boats, whereas UK road traffic deaths were 1,732 in 2015.

Ideally I would prefer to assess/reduce the risks (possible CO sources, how you use the boat etc) rather than blindly fitting another alarm. CO is a bit less dense than air, so I guess the main risk associated with boats is the enclosed space, rather than the tendency to gather in the bilges like butane. So ventilation would be (presumably) be a useful precaution; check your exhaust, and don't use your cooker incorrectly (e.g. to heat the cabin). I notice it's soluble in water, so I wonder if water-cooled exhaust systems help to reduce the risk?

 

[VicS]

I would say false alarms are certainly a nuisance, and if repeated the alarm will probably be ignored, the way most of us now ignore car alarms. The 'boy who cried wolf' story is still with us. An alarm which gives false positives is, technically, not functioning correctly.

Overall CO deaths seem to average about 70 per year in the UK (1995 - 2015) - av 2.8 per year in boats, whereas UK road traffic deaths were 1,732 in 2015.

Ideally I would prefer to assess/reduce the risks (possible CO sources, how you use the boat etc) rather than blindly fitting another alarm. CO is a bit less dense than air, so I guess the main risk associated with boats is the enclosed space, rather than the tendency to gather in the bilges like butane. So ventilation would be (presumably) be a useful precaution; check your exhaust, and don't use your cooker incorrectly (e.g. to heat the cabin). I notice it's soluble in water, so I wonder if water-cooled exhaust systems help to reduce the risk?

"sparingly soluble" is the expression in my chemistry text books!

 

[johnalison]

The solubility of gases diminishes with rising temperature, unlike other solutes, so the contribution of exhaust water must be negligible.

 

[Barnacle Bill]

The solubility of gases diminishes with rising temperature, unlike other solutes, so the contribution of exhaust water must be negligible.

So it may not reduce the CO much (though exhaust water isn't that hot - hopefully); but reading more about this in Wikipedia it seems that Deisel exhaust (although pretty nasty stuff) contains "one twenty-eighth of the CO" of gasolene engine exhaust. Which is interesting, and perhaps explains why there are so few deaths in the stats associated with deisel fuel.

So no, I'm not going to buy a CO alarm. The risk (if you are aware of it, and minimise it) seems to be negligible, and I don't want another alarm which is susceptible to false positives.

 

[NormanS]

So it may not reduce the CO much (though exhaust water isn't that hot - hopefully); but reading more about this in Wikipedia it seems that Deisel exhaust (although pretty nasty stuff) contains "one twenty-eighth of the CO" of gasolene engine exhaust. Which is interesting, and perhaps explains why there are so few deaths in the stats associated with deisel fuel.

So no, I'm not going to buy a CO alarm. The risk (if you are aware of it, and minimise it) seems to be negligible, and I don't want another alarm which is susceptible to false positives.

Tempted to say, "famous last words"

 

[Cantata]

...........So no, I'm not going to buy a CO alarm. The risk (if you are aware of it, and minimise it) seems to be negligible, and I don't want another alarm which is susceptible to false positives.

I'm a bit shocked at your decision.
I've had two of the Kidde CO alarms for some years, one at home close to the gas boiler, one on our boat. Never had a false alarm. Seen the numbers climb on the one on board once, we were shut in on a cold evening with everything going on the cooker. A salutory lesson - overhauled the burners after that.

 

[Lon nan Gruagach]

Overall CO deaths seem to average about 70 per year in the UK (1995 - 2015) - av 2.8 per year in boats, whereas UK road traffic deaths were 1,732 in 2015.

Those figures are quite damning for boaters!
70pa nationwide and 2.8pa in boats. I suggest that less than 2.8/70, thats 4%, of the population use boats. So there is a significant extra risk involved with boats.

again, 2.8/1732 (about 0.16%) nationwide the number of hours spent on roads is tens, if not hundreds of thousands of times greater than hours spent on boats. The risk of CO death on a boat is therefore much greater than death on the roads.