Carbon Monoxide Alarms Sounding…

[chrisdobson45]

We opened up Mystic Lady this morning after a few days away to find the CO alarm in the fore cabin was going off. There were three CO alarms fitted to the boat when we purchased her earlier this year and all appeared to be working when tested.

All had a date of manufacture in 2017 so we decided to replace all of them, just in case they were reaching the end of their useful lifespans, and we how have a digital sealed unit for our main sleeping cabin (mid cabin), one in the salon, one in the fore cabin and one in the rear cockpit, above the engine bay. 
 

This evening, the alarm in the mid cabin went off, followed by the one in the salon. We immediately vented the boat by opening windows and the door to the cockpit, the digital alarm was showing 36ppm but has dropped to normal now. The curious thing is we haven’t used any pathing that could be responsible for producing CO. We do not have gas on the boat, the oven & hob are electric and we haven’t used the diesel heating for a week. We haven’t fired the engines up since they were serviced last week. I wonder if our neighbours have had their diesel heating on and the exhaust fumes have been drawn into our boat…

The digital alarm is now in the main salon and it’s showing a slowly increasing value of 17 - 19ppm… very worrying as we can’t determine where the source of CO is

[Smoggy]

Which way is the wind blowing and what running upwind?

[chrisdobson45]

It’s been blustery all day but has calmed somewhat now. We are moored at the western end of the western basin at Cove with a shed to our stern so the wind tends to swirl around and push us to starboard.

We’ve had nothing running today that would generate CO. To port beyond the finger quay there’s a Broom 30 and we haven’t seen its owner since the weekend. To starboard is a boat which I suspect has had its blown air heating on earlier this evening, and probably also this morning as the owner and partner are in residence (I believe they live aboard). This could be why the CO alarm in our fore cabin was sounding when we arrived this morning.

we’ve ventilated the boat and it’s now cold but CO levels are lower (12 - 13ppm). It’s going to be along night…

[MauriceMynah]

I raised this point many years ago. What should one do if the Co alarm sounds for no apparent reason? I never did get a sensible answer. All I could come up with was "ignore it ".

I have been lead to believe that the propellant from aerosols can be a culprit so ask if your good lady has been busy with the Pledge ( not a problem on my boat ) fly killer or air freshener?

I think the main problem is that if this happens too frequently   these alarms will be treated like car alarms, always ignored.

How many times do we hear of batteries being removed from smoke detectors? How often have you witnessed anyone investigating a car alarm other than to see which car it is? 

No! Sad to say that "Wolf" has been called too often now, and alarms no longer alarm anybody.

[Vaughan]

21 minutes ago, MauriceMynah said:

I have been lead to believe that the propellant from aerosols can be a culprit

I think you are talking here about the effect of hairsprays, etc., on gas detectors, since the propellant for aerosol sprays is actually butane gas.

It is perfectly possible that the fumes from the exhaust of a diesel heater have found their way in through the windows.  I have often been suspicious that their fumes, on a stern-on mooring, are a lot more pollutant than a diesel engine running but no-one seems to bother about them.

[MargeandParge]

Only a thought I have seen covers or items on decks covering the vents.

Another thing that you could try is turning on the bilge blower and see if this reduces the volume. Might give you a clue as to source..

I think a gas cooker can do it.

Certainly a head scratcher when you have nothing running. 

Regards Marge and Parge 

Edited June 3, 2023 by MargeandParge
Add a bit

[Vaughan]

46 minutes ago, MargeandParge said:

I think a gas cooker can do it.

A gas cooker - in good condition - does not emit CO.

There is a big difference between CO2 and CO.

[addicted]

This happened to us in the early hours of one night last Summer. Our first thought was that the alarm was malfunctionioning. but an hour later the other alarm also went off. It turned out to be fumes coming from a  faiing battery.

 

Carole

[chrisdobson45]

2 minutes ago, addicted said:

This happened to us in the early hours of one night last Summer. Our first thought was that the alarm was malfunctionioning. but an hour later the other alarm also went off. It turned out to be fumes coming from a  faiing battery.

 

Carole

 

[chrisdobson45]

We’ll have the batteries checked, they seem to be performing ok but we have little idea of when they were installed and what their performance was prior to us purchasing the boat. 
All alarms have been “normal” since 12.30am, the digital alarm in the mid cabin is reading “all clear”. I’m waiting for our neighbour to awake, to see if he has his heating on. 
There is an engine bay vent and another through hull fitting on his boat close to our mid cabin porthole, no idea if his diesel heater exhausts on this side of his boat…

[Tobster]

I’ve had the same thing on my Bayliner, the sun on the fibreglass superstructure can also raise the levels inside the boat.

always best to ventilate to prevent the buildup.

I would treat any alarm as real until you prove otherwise. My boat has three fitted alarms and I have a small unit that I place near the main cabin as a secondary check.

[chrisdobson45]

We’ve been out of Cove this afternoon, all four CO alarms have behaved themselves, even the one in the engine bay. Our neighbour has remained in the Marina so we’ll see what happens later tonight…

[SteveO]

We had this happen the other week. Arrived at the boat to find both CO alarms sounding off. Changed the batteries on the alarms and the problem seemed to go away, only to have it start again that evening. Eventually traced the problem to our engine starter battery, which is separate from the main battery bank, which was being boiled dry by the "intelligent" charging system. Replaced said battery and the problem went away. Aparrently CO alarms sense several things other than carbon monoxide, including fumes from dying batteries.

[chrisdobson45]

Today's diagnosis, one cooked battery so I've bitten the bullet and replaced them so hopefully no more being awakened by a CO alarm...

[Karizma]

good to know - thanks for sharing

[MargeandParge]

Hi Chris was it definitely the cooked battery?

Kindest Regards Marge and Parge 

[chrisdobson45]

It was a cooked battery. The engineer from Horning Pleasurecraft said he could smell a cooked battery when he was in the engine bay and had the battery box open. We had the entire domestic bank replaced and since then all CO alarms have behaved. 

[MargeandParge]

Many thanks our alarm is in place. 

Kindest regards Marge and Parge 

[HEM]

On 03/06/2023 at 06:50, MauriceMynah said:

I raised this point many years ago. What should one do if the Co alarm sounds for no apparent reason? I never did get a sensible answer. All I could come up with was "ignore it ".

Don't go down that road - it can cost you your life...

On 03/06/2023 at 15:38, Tobster said:

I would treat any alarm as real until you prove otherwise. My boat has three fitted alarms and I have a small unit that I place near the main cabin as a secondary check.

This policy would have saved at least 2 lives some time back.

Its been my pleasure to have visited the offices of the German Air Accident Investigation folks (BFU) in Braunschweig a few times, along with a group from my flying club - a former club member is one of the accident investigators.  Following a lecture which included in-detail analysis of a particular crash (such as AF447) we would be led into the "wreck-hall" where the sad remains of numerous types of aircraft from airliner to hot air ballons were resting.

One particular heap of metal was caused by CO poisoning due to the heat-exchanger corroding & letting exhaust gasses into the cockpit.  The tragic thing was, the owner had perviously had an electronic CO-detector fitted but had it removed "because it was always sounding alarm".

 

 

[Mouldy]

Moored yesterday lunchtime at Beccles Yacht Station.  The sun was out and it was very pleasant.  We had our saloon windows open, the galley window open as well as the doors to the aft well, where our canopy was also open.

I lit the grill and within seconds our CO alarm was sounding.  Pushing the button to silence it didn’t stop the bloody thing, so I took it off the wall and the wife went outside with it, covering it with her hand to kill the sound.  She was outside for about fifteen minutes and it still wouldn’t switch off, so out of desperation, it was drowned, not in the river, but in a sink full of water.  That did the trick.  Less than three years old, too.

We left it in the aft well overnight with a view to take it home to be thrown safely with our electrical waste.  The alarm light was still flashing.  Don’t get me wrong, I’m in favour of these to promote safety, but to be fit for purpose, they have to be reliable.

I hope the new one is better.

[MauriceMynah]

Was the grill functioning properly?

[Mouldy]

2 minutes ago, MauriceMynah said:

Was the grill functioning properly?

Yep.  And it was very well ventilated.

[MauriceMynah]

I have several CO alarms onboard one right next to the Chinese heater,  another by my bunk. The third one is in the wheelhouse and a fourth close to the cooker. Finally I have one protecting the aft area astern of the galley.

I'm working on the principle that if just one goes off, I'm on high alert. If two or more go off I take action. What action I take rather depends on which ones are sounding, the weather, and the availability of the gin bottle.

[FairTmiddlin]

46 minutes ago, MauriceMynah said:

I have several CO alarms onboard one right next to the Chinese heater,  another by my bunk. The third one is in the wheelhouse and a fourth close to the cooker. Finally I have one protecting the aft area astern of the galley.

I'm working on the principle that if just one goes off, I'm on high alert. If two or more go off I take action. What action I take rather depends on which ones are sounding, the weather, and the availability of the gin bottle.

MM if evacuation is necessary don't forget the order of evacuation. Men and Gin first.

[Mouldy]

48 minutes ago, FairTmiddlin said:

MM if evacuation is necessary don't forget the order of evacuation. Men and Gin first.

If it’s just the gin and not the contents of the cocktail cabinet, make sure it’s the bottle with the most in!