CO in Engine Room and migrate to Cabin

I'm a 3-yr owner of a 32 yr old GB with a 12 yr old 8.5 KW Diesel Generator. For first time, I had CO alarms go off in both forward and aft cabins while only generator running. I solved problem temporarily by running both engine room ventilation fans (had never used them before). Can anyone give me insight into what my first step should be to determine a generator engine exhaust leak other than visual inspection of joints?

Co2 sensors do go bad

Are the CO detectors for marine use? Household detectors often alarm unecessarily on boats.

Had a persistent aggravating problem with a "marine" CO detector. Kept chirping. Changed the battery. Gave it fresh air. All "fixes" were very temporary. Finally realized that my 18 month old marine detector was out of date and giving an "end-of-life" signal. Not sure there really is any difference between domestic and marine, except store turnover is much higher for domestic, so better chance of getting a good unit with 5 year real life.

Diesel engines produce very little CO when running right. So even with an exhaust leak it shouldn't produce enough CO to migrate into the main cabin. And given that both alarms tripped, it is hard to see that this is an alarm failure.


I would look at the genset engine. Is it producing black smoke, which could be an indicator of excess fuel or restricted air which will produce more CO. Coked up exhaust ports or exhaust elbow can cause this.


Also follow the exhaust path and put your hands around each joint to feel for leaks, but keep those exhaust fans running while you do this ;-).


David

Check your batteries, if you were running a charger when the genset was running, one or more could be dry and producing hydrogen related gasses which often set off CO alarms.

I have never had a main or genset set off CO alarms in now over a decade of living aboard 2 vessels.

Both had older and not necessarily perfect engines or gensets.

But on both boats when I have had a battery issue....I have had the CO alarms sound.

psneeld said:

Check your batteries, if you were running a charger when the genset was running, one or more could be dry and producing hydrogen related gasses which often set off CO alarms.

I have never had a main or genset set off CO alarms in now over a decade of living aboard 2 vessels.

Both had older and not necessarily perfect engines or gensets.

But on both boats when I have had a battery issue....I have had the CO alarms sound.

Click to expand...

What he said. According to Kidde (who makes the home detector I have on my boat) battery fumes will make the detector go off.

psneeld said:

Check your batteries, if you were running a charger when the genset was running, one or more could be dry and producing hydrogen related gasses which often set off CO alarms.

I have never had a main or genset set off CO alarms in now over a decade of living aboard 2 vessels.

Both had older and not necessarily perfect engines or gensets.

But on both boats when I have had a battery issue....I have had the CO alarms sound.

Click to expand...

Yep....quite likely the case!!

psneeld said:

Check your batteries, if you were running a charger when the genset was running, one or more could be dry and producing hydrogen related gasses which often set off CO alarms.

I have never had a main or genset set off CO alarms in now over a decade of living aboard 2 vessels.

Both had older and not necessarily perfect engines or gensets.

But on both boats when I have had a battery issue....I have had the CO alarms sound.

Click to expand...

Exactly what we have found-CO alarm was actually a battery issue.

Batteries again! I received a call from my slip owner saying an alarm was sounding on my boat. I rushed over to find the battery charger was malfunctioning, the batteries were bubbling away. Shut down the charger, aired out the cabin and all was OK.
The batteries were in the engine room, hatch closed, the CO monitor in the saloon.
Boat was on shore power neither main engine or generator running.

djmarchand said:

Diesel engines produce very little CO when running right. So even with an exhaust leak it shouldn't produce enough CO to migrate into the main cabin.
David

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I was thinking the same thing. I believe I read that a diesel engine puts out 10% of what a gas engine does, so I don't even have CO detectors since we switched to a diesel boat serval years ago.

And by the way, I have first-hand experience with CO poisoning. Long story short I almost passed out once. Nasty stuff.

The comments about the detectors are good ones others are making

CO from Engine Room to Cabin

Hey everyone, thanks for the good ideas for things to check - mainly the batteries.

Fletcher500 said:

I was thinking the same thing. I believe I read that a diesel engine puts out 10% of what a gas engine does, so I don't even have CO detectors since we switched to a diesel boat serval years ago.

And by the way, I have first-hand experience with CO poisoning. Long story short I almost passed out once. Nasty stuff.

The comments about the detectors are good ones others are making

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May I ask why you don't have a detector? With first hand experience with co poisoning I would think you would make sure to always have a working detector.

kwmeyer13 said:

May I ask why you don't have a detector? With first hand experience with co poisoning I would think you would make sure to always have a working detector.

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I was told by my insurance company to get one or they would drop me

Diesel does produce much less CO than gasoline however, the effects are cumulative. It can take up to two weeks for CO to clear from your blood (according to a hematologist I did a survey for)...... a little bit each day adds up.

kwmeyer13 said:

May I ask why you don't have a detector? With first hand experience with co poisoning I would think you would make sure to always have a working detector.

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Good question. I had several on our gas boat. I figured I didn't need one with the switch to diesel, but better safe than sorry. I will get some.

You have discovered why engine spaces are sucked on with blowers , and never pressurized.

Brought to my attention......

Carbon Monoxide Toxicity: Background, Pathophysiology, Epidemiology

CO is eliminated through the lungs. Half-life of CO at room air temperature is 3-4 hours. One hundred percent oxygen reduces the half-life to 30-90 minutes; hyperbaric oxygen at 2.5 atm with 100% oxygen reduces it to 15-23 minutes.

https://www.google.com/url?sa=t&rct...de.PDF&usg=AFQjCNGZFy4b-E6mL1iwUId_Ifmk3z3WFg

Carbon monoxide is eliminated unchanged via the lungs. The decline in COHb concentration
depends on the rate of carbon monoxide release from haem proteins, alveolar ventilation, oxygen
concentration in inhaled air, duration of carbon monoxide exposure, and the level of COHb
saturation. The formation of COHb is a reversible process, but because of the tight binding of carbon
monoxide to haemoglobin, the elimination half-life while breathing room air is 2–6.5 hours depending
on the initial COHb level. The elimination half-life of COHb is much longer in the fetus than in the
pregnant mother (1–3, 28).

If the levels are low, so is the toxicity rate. Therefore I believe the levels of sypmtoms as the toxicity increases are much more likely to be pronounced for longer periods of time. Be aware that on a boat there can always be a presence....so if any of the symptoms are present, expose the boat to fresh air and reduce any possible source. CO can be deadly, but usually to the totally unaware.

The only first-hand experience I had with CO was when my home oil burner malfunctioned. Finally realized that there was a crack in the furnace hot air heat exchanger that was allowing combustion products to enter the hot air stream to the living spaces. Probably had the problem for some weeks before we became aware of the issue. This pre-dated universal home CO detectors in the 1980's. It explained the headaches we were both waking with in the mornings!!
So since heating oil is basically the same as diesel fuel, even diesel can generate enough CO to have a health impact.
We also had CO detectors on our trawler mandated by the insurance company.
As previous, buy the domestic ones with full shelf life, not the stale marine ones!!