CO Alarm Puzzle

I need some help from the smarter than me (and that does not take much at times) minds on this forum. My bride and I purchased a 1984 Fu Hwa Europa Trawler in November 2015. We have been working thru the issues, and a couple of weeks ago installed a combination CO and Smoke detector. On the way home I received a call from the Marina that we had an alarm going off. When i returned it was the CO alarm. Keep in mind the boat had not been run in about a week and half. I removed the detector and the next weekend with the engines still not having been run, carried the detector back to the boat and it sounded again after about 30 minutes with the boat closed up.

I purchased another detector for just CO that shows the PPM levels and tested it today. With the boat closed it alarms and shows levels of 400+PPM. I opened up the boat and let it air out and retested with no alarm and levels less than 50PPM. Put the alarm in the bilge by the main engine and immediately sounded.

The boat is all diesel (Lehman 120 main and Kohler generator). No gasoline or gas engines on board or near our slip. Outside the alarm shows no PPM of CO. We ran the boat yesterday for about 6 hours (Lehman only - not the generator) with no issues. I am not seeing any telltale signs of an exhaust leak anywhere - no salt water or sooting. I did spend several hours earlier this week cleaning up the bilge area and looking all over the place for signs of an exhaust leak.

Looking for ideas of what could be causing this. My exposure to diesel engines says they produce very little CO - CO2, yes but very little CO. I don't want to spend a night on the boat until I have this solved. Any ideas?

Sorry for the long post and thanks for your assistance!

John

Perhaps alarming on battery off-gassing?


What brand/model of alarm? Dunno if you saw it, but there's been a recent thread on the topic... and that eventually began touching on the pros/cons of household units versus marine/RV units. With no particular earth-shattering conclusions about one of the there, of course.


-Chris

ranger42c said:

Perhaps alarming on battery off-gassing?


What brand/model of alarm? Dunno if you saw it, but there's been a recent thread on the topic... and that eventually began touching on the pros/cons of household units versus marine/RV units. With no particular earth-shattering conclusions about one of the there, of course.


-Chris

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Interesting - is that gas similar enough to show as CO?

The original was a combo unit purchased at Lowes. The Second one that shows the PPM was an Arikon from Amazon - also a home unit.

John

Iron oxidation may be the culprit. Are your alarms being placed in living quarters or E.R. ? Carbon Monoxide is slightly lighter than air so leaving something open up high might correct the build up of CO. A well vented E.R. or a small fan running in the E.R. even when you are not at the boat may correct all issues.

ulysses said:

Iron oxidation may be the culprit. Are your alarms being placed in living quarters or E.R. ? Carbon Monoxide is slightly lighter than air so leaving something open up high might correct the build up of CO. A well vented E.R. or a small fan running in the E.R. even when you are not at the boat may correct all issues.

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I originally had both alarms in the main cabin of the boat but with the alarms sounding all the time I moved the second one around to different locations to try to track down the source. It was strongest below decks.

John

This is an interesting topic. I will try to get a better handle on Iron Oxidation and resulting gasses. I am assuming that you don't smell anything. The nose is usually an excellent indicator of many gasses.

ulysses said:

This is an interesting topic. I will try to get a better handle on Iron Oxidation and resulting gasses. I am assuming that you don't smell anything. The nose is usually an excellent indicator of many gasses.

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Unfortunately, CO is odorless and colorless.

dhays said:

Unfortunately, CO is odorless and colorless.

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Very true - no odors related to batteries that I can tell. I have worked on diesel transit buses in my past with 8D batteries that would give off hydrogen and know that smell. After a couple of those go boom and you remember that odor very well!

Salty just smells like a 32 year old trawler inside to me.

John

Yes, it is odorless and colorless but it does often combine with other gasses that can be smelled and/or seen. That is why "I assumed" that he was not smelling anything.

My next question would be is if you have an automatic or manual fire extinguishing system that may be leaking in the E.R. ? If so, when was its last inspection ? As far as the potential for Iron Oxide causing a false alarm that might be a question better suited for the alarm mfg.

You might want to see what other gasses the offending detector might sense. Many also do hydrogen, which like CO is colorless and odorless as well as stibene aka antimony hydride which stinks and is also quite toxic. Stibene is what off gasses from over charging lead acid batteries. Fwiw all these gasses are lighter than air so an engine room mount may or may not pick them up.


Spell check via iPhone.

I gave had one alarm from a battery...so has Jay Leonard another member here.

He contacted Kiddie and they verified off gassing of a battery will trigger them.

Let's see if there is a battery issue...and if so...maybe home versions have advantages too.

On a sharp right turn of the thread... Do you have kids?

I found that our diaper pail set off our CO detector if they were within 20 feet...

Every parent knows that poo is noxious, but I never knew it would trip a CO detector (often at 3-4am)...

Stu

Short article today in Boat US mag. concerning smoke alarms for boats or lack thereof. They suggest a R.V. designed alarm until such time as boat standards are developed. Seems to be more concerned with corrosion than false alarms.

ulysses said:

Yes, it is odorless and colorless but it does often combine with other gasses that can be smelled and/or seen. That is why "I assumed" that he was not smelling anything.

My next question would be is if you have an automatic or manual fire extinguishing system that may be leaking in the E.R. ? If so, when was its last inspection ? As far as the potential for Iron Oxide causing a false alarm that might be a question better suited for the alarm mfg.

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No fire system in the bilge area only manual fire extinguishers above decks.

John

psneeld said:

I gave had one alarm from a battery...so has Jay Leonard another member here.

He contacted Kiddie and they verified off gassing of a battery will trigger them.

Let's see if there is a battery issue...and if so...maybe home versions have advantages too.

Click to expand...

I have 2 8D batteries for the house and main engine start. I also have a group 13 for the generator start. I will verify the voltages next time we are at the boat - probably tomorrow.

Thanks

John

stubones99 said:

On a sharp right turn of the thread... Do you have kids?

I found that our diaper pail set off our CO detector if they were within 20 feet...

Every parent knows that poo is noxious, but I never knew it would trip a CO detector (often at 3-4am)...

Stu

Click to expand...

No kids still at home - and so far my bride and i are not in diapers...yet

John

Most household CO detectors don't differentiate between carbon monoxide and hydrogen. They will read high near you batteries, as several posters suggested. I'd say this is the cause of the alarms.

Even though hydrogen is not toxic, it is flammable, but ignition will not occur at levels less than 18% (180,000 ppm)

If the 400 ppm reading you got is hydrogen, this is not a problem, other than the confusion it creates with you CO alarm.

I wouldn't suggest to just assume this is the cause of the high readings. It may be worth venting your battery boxes externally, or maybe changing the batteries to AGM's next time they need replacing.

Go look for any batteries that are warmer than ambient.

Years ago had the same co alarm problem, ended up being the batts off gassing.

Ski in NC said:

Go look for any batteries that are warmer than ambient.

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So just as I expected the collective wisdom on this forum was exactly correct. When I returned to the boat today and looked into the engine compartment, I had 2 8D batteries emitting that rotten egg smell and very warm to the touch. IR temp gauge shows 133 on one and 131 on the other. Shut off the charger (an older Protech 1250) and vented the compartment.

After removing the old batteries I turned the CO monitor back on and it shows 0 PPM both in the cabin as well as in the engine compartment.

Many thanks to all who helped figure this out. Now I just have to decide what batteries to put back in and if I need to change the charger. Sounds like another boat buck is on its way out of my bank account

Oh well, part of the deal.

John

Hmmm..another plus for those home CO detectors...

Well,.........We have two CO detectors on board and neither warned us of an issue. Returning to the boat after a few days I noticed a strong odor as soon as I opened the door. Checked the ER where it was noticeably stronger. Found one 6 year old 8D just beginning a thermal runaway and disconnected it with disposal following. Each detector is a different brand. Neither gave any warning while aboard a few days earlier, or when the action was really ripping. Batteries were up to snuff in both, so very curious after reading this thread. Junk em' or keep em'?

What...the batteries or the CO detectors?

Sounds like both need replacement.....

Take both of them and hold near the exhaust of your gas powered car/truck while the engine is running. They should sound in short order if working.

John

Now, I should have thought of that!

JP2 said:

Now, I should have thought of that!

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Just not in the garage with the door closed

I got a call that an alarm was beeping, went to the slip and found batteries gassing the old charger was on the blink and causing a good bit of bubbling from the 8ds