Carbon Monoxide alarming in cabin

Aprice

Has anyone else have issue with the co alarm(s), I have 2, going off in the cabin with engines running for a few minutes before departing the dock? I can smell exhaust in there but its not entering through the windows or the hatches as they were closed.
My guess is it is seeping from the engine compartment intk the cabin. My question is is this normal as I havent had this happen on my previous boats. If the engine exhaust through the drives or at the transom is it likely reentering in the intake vents on the side and then settling at the bottom of the bilge and traveling along the aft into the mid bilge? The blower is on and working properly while this is happening. 

Any thoughts or ideas. 
Thanks 

rasbury

The only time mine went off I was traveling with the camper package up but the back was open and tho some how pulled that exhaust back into the boat- is this a new problem, doing something different like I did? History!

Aprice

It's a new to me boat and it's happened a few times. The camper top was up but the exhaust smell wasn't in the cockpit area. Only the cabin. 

Black_Diamond

If the camper canvas is up, it will 'tailgate' the exhaust back into the cabin. 

LaRea

Does your detector have a born-on date?  If not, or if it's older than 7-8 years, I'd replace ($40 each with a sealed 10-year battery).  At least you'd have confidence that the readings are accurate. 

Liberty44140

Yea if I am runing I either need to remove everything but the top behind the arch or I need to fully close everything or I'll get an alarm down below. Opening the front window helps keep air moving out. 

Michael T

IF your alarm is in good working order then a signal below is of very great concern. Modern units sample the air continuously to avoid false alarms - so if a good quality units is going-off that is a very dangerous situation. We had a good discussion on this topic on this forum a couple of years ago. In it I mentioned how I made myself temporarily ill (I think I may have called myself an idiot) by not paying attention to the CO alarm. As @Black_Diamond stated above backdrafting was the culprit in my case. I had to make sure I had a fair bit more air entering the cockpit that could exit at the back - more than I had expected - prior to my experience. In my case the backdrafting was not an issue at idle speeds with the canvas off - it was very pronounced at cruising speed.

Stodge

I had an older CO detector that was hard-wired to the 12V power and would go off if the voltage got below 11volts.  

On another note, those detectors are only good for about 10 years.  

Aprice

Thanks for the help guys. I am a full time firefighter/paramedic and have an understanding of the dangers of CO. I bought 2 new combo  units smoke and CO alarms last month. It's not the units. Possibly a backdraw of air into the cabin. My side curtains on the camper top have the screen vents on it and I can feel the blower pushing air out, maybe the intake air coming back in is just back drawing the air from the exhaust. Again this is only while idlingat the dock. I will try to run the boat again and have the cabin door shut and see if the exhaust smell returns and the co alarms trip then I know it's not from back draft/drawing. 

MarkB

Are the beeps every 30 seconds apart, or more continuous. The warning comes first, and it doesn't take much CO to get it going. Some backdraft, or wind in the wrong direction, could easily set it off.

Aprice

It alarms constantly and then the silence alarm holds for a few seconds and alarms again. I truly cant shut them off unless I unmount the or the CO has dissipated below the minimum  parts per million.  

rasbury

Put some detectors above so they can go off too...

summerx

check for an exhaust leak.  the first season I had my 310 my CO detectors were going off but I couldn't explain it.  turned out to be a hairline crack in the exhaust manifold.  replaced them both and problem solved.  I believe the exhaust was coming in thru the rear aft cabin wall.

dalek

I know that you have checked it, but for your own safety, are you absolutely 100% sure your blower is not backwards or wrong polarity?

davidbrooks

I ran into that last fall with my 342.  I was running with the camper top on, eisenglass and side curtains....the admiral was Chilly.  The alarm was going off in the cabin.  I opened up the hatches below to get some air flow and also opened up the Windshield.  Later i checked the blowers and actually replaced the exhaust boots last winter.  I went with boots that clamped on vs the slip in kind.  Personally i think that it made a big difference.  They were a pain to get on but worth it.  Now i run with both blowers on as well.

Aprice

I think it is be an exhaust issue because I could smell it in the cabin. The starboard engine has water stains on the riser on the left when looking at it from the belt side. I will have to replace the exhaust boots. 

The blowers are both functioning and drawing air from the bildge and out the vents on the sides.


Thanks for the help everyone. 

rasbury

Hopefully that solves your problem, that is scary stuff! I am going to install some on my upper deck, at least one somewhere as I know I was pulling fumes in with the camper package up- probably just a perfect storm of speed and wind direction but we never smelled anything but it must have collected enough down below to fire them off...at first I thought they were just bad but they are pretty new!

06Rinker270

What carbon alarm does everyone use?  

Liberty44140

@Aprice if you have all canvas in front of the radar arch closed but all canvas behind the radar arch open/removed (except the Bimini top) does your alarm still go off in the cabin? 

Aprice

@Liberty44140  It did one time, but I only smell the exhaust in the cabin.  After thinking about the possibilities and seeing signs of a leak from a a riser boot, I tightened the clamps and haven't had an alarm since. I still have concern just because I maybe have ran the engines for an hour total since tightening the clamps.  I will keep everyone informed if issue still exist.