CO Monitors

[SereneWarrior]

This one has me stumped. It may be nothing, but given how dangerous carbon monoxide can be I want to be certain. Recently, since the weather on the Chesapeake Bay has finally warmed up to near normal levels, I've experienced CO alarms. I have a 1970 MY with an installed, hard wired carbon monoxide sensor system that has sensors in the salon, the master stateroom and the Vee-berth. Last winter, I also installed cheapo Walmart battery operated CO alarms in the VIP stateroom and just outside the enginerooms in the centerline passageway.
I usually button up the boat completely once I leave on Sunday nights and don't open it up again until I return on Friday. A couple weeks ago, I got a mid-week phone call from my marina neighbor to let me know that there was a beeping alarm going off onboard my boat. When I got there, all three hardwired sensors were alarming, as well as the two battery operated ones. I opened up the boat and within a minute all the alarms silenced and reset. There was no smell of any kind, but CO has no smell so that did not reassure me. Having cleared the alarms, I left a couple of portlights open when I left the boat. Upon returning to the boat a couple days later all was well and all CO alarms were green/unalarmed.
As part of a planned maintenance action, I replaced all my batteries a week later. The old batteries were nearly eight years old and weakened, so I thought perhaps they were gassing and causing the CO monitors to alarm. Yes, I know batteries don't make carbon monoxide, but I had no other possible explanations. As part of the battery replacement, I neutralized the electrolyte that had been leaked/spilled in the battery boxes and cleaned/disposed of it properly. When I secured the boat, I closed up the portlights, shut down the ventilation/AC and went home for the work week. However, when I returned the two Walmart CO alarms were beeping again. The installed system was all green and not indicating any CO problem. Once again, I opened a couple portlights and the store bought alarms silenced and reset immediately.
Throughout all of this, none of the traditional sources of CO were present. The engines and generator weren't run when the alarms went off. I've checked the bilges and they are dry, but I added a bit of Chlorox to them just in case I had strange critters making gas in them. That didn't change anything, but the boat smells lemony fresh now.... My sense is this has something to do with the hotter, humid weather we've had recently, but that alone doesn't give me any assurances of what's happening here. Can anybody provide any explanations for this "alarming situation"?

 

[Angela]

Could there have been a boat next to your running its engines? The only time mine ever went off was when I was rafted up next to a boat running a genny. And, these do just utterly fail from time to time and need to be replaced entirely. I just bought one this week to replace one that just got old. Given your description of all of them having gone off, it doesn't sound like an "age failure."

 

[MikeP]

Batteries gassing H will trigger a CO alarm. I had heard of this possibility and have verified it - every time I do an EQ charge, the CO alarms will eventually trigger. So if you are charging the batts, it is a possibility depending on the amount of charge and location of the alarms.

That being said, as you noted, you want to be SURE it is H and NOT CO causing the problem. I have become comfortable with the battery charging thing since it happens every time but I suppose owning a canary might be the only foolproof method!

 

[SereneWarrior]

Angela, I agree it's too much of a coincidence to be age failure of all the monitors simultaneously. And there wasn't anybody running an engine or genny nearby when the alarms went off. That's what really has me scratching my head. Further, the boat was sealed up tight. Theories from the ancient warriors (not an insult to ancient warriors...I am one, too!) at the marina range from, "You're cooking your batteries." to "It's outgassing from the fiberglass." Neither of these explanations makes much sense to me. My battery monitors read completely normal and the batteries are new since the first alarms went off. And outgassing from a 40 year old hull? Seems like a bit of a stretch to me for it to occur now when it hasn't set off any alarm for the past three years I've had the boat. Still stumped....

 

[SKYCHENEY]

You say you have new batteries, but what charger do you have? Could it be overcharging and gassing hydrogen out of them? As MikeP stated, H will trigger the CO alarm. I have had that happen before as well.

 

[SereneWarrior]

Sky/Mike, Agree it's likely the batteries gassing H as they are on charge. I have the older Heart Interface Freedom 2000 Inverter/Charger(s) that were installed by a previous owner 13 years ago. Only reason I keep looking for other answers is that the readings on the monitors have not changed much in the three years I've had the boat and there has never been a CO alarm before now. The chargers get the batteries up to 35-36V and hold them there, but that's how it has been since I've owned SERENITY. I keep asking myself, "What has changed that could be causing the problem?" Further, if it is the batteries what should I be doing to alleviate this? Could turn off the chargers, I guess, but according to the literature they should sense the batteries' condition and stop charging when appropriate all by themselves. Any advice? I really do enjoy the logic/reasoning back and forth on my boat's issues. She's my first and I'm benefitting immensely from the thought processes I get here!

 

[SKYCHENEY]

How often do you have to add water? If they are gassing, electrolyte levels should be going down.

 

[MikeP]

I have read, though I have NO personal experience, that some CO detectors are more sensitive to H than others. However, your issue that the detectors never used to go off and now they do does indicate something has changed but it could be in the battery charging/gassing or the detectors themselves.

OR, of course, it could be some unknown source of CO...

 

[SereneWarrior]

Mike, That's my worry and what I really want to resolve. There shouldn't be any CO unless something is burning (i.e. diesel, gasoline, the boat, etc.), but something is setting of the detectors.... I do check the batteries each month and generally have to add some demineralized water each time, so I'm definitely making some H down there. That's probably the source of the problem. I'm just not experienced enough to know what else to do about it.
Sky, You mentioned this has happened to you. Any advice? Thanks in advance.

 

[fissioneng]

I am curious about this too. I found this old thread which talks about H causing the alarms.

http://www.samsmarine.com/forums/showthread.php?t=9743

 

[TopHattandTails]

IF it turns out to be the batteries over charging - you might be able to lower the "blast" on the charger to look more like a "trickle". Did that on my LaMarche last year and the batteries still get to 36vdc, but not any higher. I'd actually prefer them to take a bit longer to get there so the charge is more like a trickle charge and not a "gotta get it there now" charge. No idea if you can tune your charger - but mine was cooking batteries every 2 years due to a couple of bad diodes and a couple of capacitors. Check out the thread on "Blowing ANL 50 Fuses to the Batt Charger". Turns out my charger charges by splitting the load. 1 line goes to a battery bank to charge and the other line goes to a capacitor which goes to the other batt bank to charge. If the capacitor sees a need for an uncharged state on its batt bank - both lines charge and cook batteries. No need to regress the thread. Sounds like the only culprit in your CO / H alarm is the charger. Do you have any humidifiers / fans running while away for the week?

 

[SKYCHENEY]

Sky, You mentioned this has happened to you. Any advice? Thanks in advance.

No, not really. I have not had the problem since I replaced my Interstates with new Rolls. I don't know why that would make a difference, but maybe the old batts had a couple of cells that were bad causing the charger to boil the remaining cells.

 

[Bob Scivicque]

You night try a small 110v fan in the generator room to see if that eliminates the problem. I have one in mine (53MY) that runs 24-7. Helps with bilge odor also.

You may also want to check with CO monitor's maker to see what other molecules will cause all the fuss.

 

[Trojan]

Most CO monitors are only good for about 2+ years. It sounds like a short time. But the sensing material will build up a coating and they then start faulting. High humidity along with the age will cause a triggered fault. I always thought they should last longer given the price they sell for. With my fire place at home I just buy one every time I see them go on sale. I never purchase the hard wired ones. That's way to much money for such a short life.

BILL

 

[bostonhatteras]

how about this; go to Grainger and pick up a HANDHELD CO TESTER (short money-125.00 or so) then close up the boat the way you like to and when the alarms go off, walk around with the handheld and see where the CO concentration is the strongest. that will be the source of the CO. or just test all areas with the meter without waiting for the alarms to sound. I'm dismayed to read about the limited life span of CO alarms. I installed 2 fireboy/zintex alarms and do not recall reading anywhere in the literature of a life span as short as two years. can someone verify those claims?
good luck
Russ

 

[Angela]

I just purchased a "battery only" (no hard wire) fire/smoke/CO alarm to replace one that finally bit the dust. When I read the booklet, it said not suitable for RV or boat use. Why is that? How does the detector know the difference whether it's in a bedroom in a house or a stateroom on a large boat? I mean...a boat like this is very much like a house inside. I'm not going to worry about it too much - there have been these household detectors in here since the boat was USCG certified. They do work and I guess that all that's really important. I had a CO alarm go off when I was rafted with a 58YF and his genny set it off when the fumes came inside. I was just curious as to why the booklet said they're not for use on a boat.

 

[bostonhatteras]

probably becouse they didnt pay the UL Underwriters to do that much more testing. have you ever had a building inspector reject a perfectly good product due to lack of some ASTM rating? same thing.
Russ