Carbon Monoxide alarm ????

May 25, 2012
22
Hunter 33 Bay Shore
Hi everyone,
I have a 2005 Hunter 33 named Ripple. Recently while the engine is off and I am away from the boat the carbon monoxide alarm in the Sette next to the Navigation Station and radio, circuit board, etc goes off. It only beeps every 30 seconds or so and only one somewhat long beep. This recently started with the weather very hot and humid while the boat may be closed up for a few days in a row. Once I open up the boat and push the re-set botton it stops for awhile ( at least many hours ). What could be setting this off? The engine is off. What could be creating carbon monoxide? Or do I need to replace my alarm? Please advise. Thank You

Mike J sv Ripple
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
24,516
CAL 35 Cruiser #21 moored EVERETT WA
Here are a couple of ideas.
  1. How old is the Alarm unit? They do age and the sensor can become clogged or fail.
  2. How fresh are the batteries? When they run low they can cause problems.
  3. Do you have a cesspool brewing all sorts of stew in your bilge?
 
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capta

.
Jun 4, 2009
5,072
Pearson 530 Admiralty Bay, Bequia SVG
I put one in the aft cabin because all the exhaust hoses run under the floor and one may leak someday. When the 9-volt battery inside needs changing, it will begin to beep and not stop until the battery is removed and replaced.
 
May 28, 2015
280
Catalina 385 Atlantic Highlands, NJ
A friend of mine just described similar symptoms on his Benetau. Happened with two different alarms ( he replaced the first one thinking it was bad). After the second time he began to wonder whether the varnish or something else might emit gases in high temps that the alarm was sensing.

Hey mentioned it to me yesterday and then this post ... odd coincidence maybe but maybe not.
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
There are several types of CO detectors. Some, like the older ones on our boat, measure "CUMULATIVE" exposure plus "MOMENTARY" levels.

The theory is that a long term low exposure (say in sleeping compartment) can be very damaging, even though the total amount isn't that high.

The reason for failure of these devices could related to voltage issues, or something else. I don't know a reliable test (other that simulations with something like a laboratory experiment on your boat.)

We have four Fireboy-Xintex sensors on our boat, hard wired to our battery DC panel. Ours are the dual "cumulative" and "current" alarm type. The sensors are powered on a separate circuit breaker. We generally leave them on whenever we're on the boat (or cruising intermittently on- and off- the boat while cruising.) There are one in each sleeping compartment and one in the main cabin.

In 19 years, they've never gone off, except when you power them on and they all "squeal" for a moment to let you know they are on.

I suspect that the your squeal may be the signal that they don't have continuous our adequate power -- but that's just my guess.
 
May 20, 2016
3,015
Catalina 36 MK1 94 Everett, WA
My vote is for dead batteries in the monitor. When was the last time they were changed?? Like smoke detectors CO monitors beep when batteries are low. CO detectors with biomemetic sensors also beep after ~6 years when the sensor is no longer good.
 
Feb 21, 2008
418
Hunter 33 Metedeconk River
I have a 2006 H33. Within the last year all three of the units, the one in the forward cabin, the one next to the Nav station and the one in the aft cabin all starting beeping. I replaced all the batteries, I replaced one with a hard wired unit and they all kept beeping. I replaced them all with new smoke/CO detectors, added another above the engine compartment and all seems good. We do not sleep on the boat so hopefully this should suffice. No?
 
Dec 28, 2015
1,945
Laser, Hunter H30 Cherubini Tacoma
Make sure your batteries are topped off and not over charging. A common cross sensitive of CO sensors is hydrogen. Some are 200x more sensitive to hydrogen than co. Halogenated hydrocarbons is another one but most are not available anymore. There is a prevalent ingredient in carpet and upholstery cleaner that will mess with them also. 23 years in the fire service and 20 on the hazmat team.
 
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Sep 20, 2006
2,953
Hunter 33 Georgian Bay, Ontario, Canada
Hi everyone,
I have a 2005 Hunter 33 named Ripple. Recently while the engine is off and I am away from the boat the carbon monoxide alarm in the Sette next to the Navigation Station and radio, circuit board, etc goes off. It only beeps every 30 seconds or so and only one somewhat long beep. This recently started with the weather very hot and humid while the boat may be closed up for a few days in a row. Once I open up the boat and push the re-set botton it stops for awhile ( at least many hours ). What could be setting this off? The engine is off. What could be creating carbon monoxide? Or do I need to replace my alarm? Please advise. Thank You

Mike J sv Ripple
This one is located right above the batteries and battery charger. Could be from the batteries.
It's also original ( I'm guessing ) so over 10 years old and time for new one. I just replaced all 3 of mine.
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
If it's hydrogen or nitrous dioxide or whatever causing "false positive" alarms from a CO detector that results frp, excess out-gassing from lead-acid batteries, that could be a sign of an issue with the batteries or your charging system. I might also be related to excess ambient heat in the battery compartment (usually the result "in" the engine compartment location of the batteries) or a locker that really isn't vented but gets significant solar heating.
 
May 25, 2012
22
Hunter 33 Bay Shore
the unit is from 2005, it does not have batteries it is wired into electrical system, there is no cesspool, but the bay is filthy.
The Boat batteries are being charged while it is shore plugged in. Yes, humid lately.
I am gathering from all the comments that I should replace them first and see.....
Thank you all for responding.

Mike J sv Ripple
 
Jan 1, 2006
7,980
Slickcraft 26 Sailfish
I think the life span of the hard wired CO monitors that are used in the Hunters is a couple of years. I think you need to replace the monitors. I'd like if they lasted longer but it isn't my call.
 
May 24, 2004
7,213
CC 30 South Florida
Just one thought for your consideration. Boat wiring is finicky, after a few years voltage drops can cause problems for hardwired components. If it were me I would disconnect the OEM sensors and replace with new battery powered units .
 
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MitchM

.
Jan 20, 2005
1,031
Nauticat 321 pilothouse 32 Erie PA
RX: install new detectors. Here's some info from a pro:
"...I have found that the first generation CO detectors cause the most problems. The battery/sensor pack would be in alarm, yet the colored discs inside the sensor would still indicate that therwe was little or no CO exposure.
A related story....We were detailed to a CO detector activation. On arrival, we entered the home with the Industrial Scientific multigas meter. We found the detector to be an old First Alert CO detector. The funny thing was, the house had electric heat, electric water heater and an electric stove...no fossil fuel appliances or fireplace in the house....‎" The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
Lt. Ray McCormack, FDNY