Something sounds strange and its more than farting. I don't think I have ever had a CO detector go off even with the deisel inboard running hard.

Exhaust from a neighbouring boat getting sucked down your vents or an open port?

 

I doubt it because it's been windy and when I took the detector into the companionway, the number dropped.

 

Do you have a CO or CO2 detector? Combusting propane produces CO2. Doing so with insufficient oxygen produces CO. I doubt that an enclosed boat would be oxygen starved, but I suppose it’s possible over time.

First you need to know the difference between CO and CO2 to figure it out. Since CO2 detectors are specialty devices, I suspect you mean CO. These use IR to detect so it’s possible other airborne elements are causing it to false.

 

Do you have a CO or CO2 detector? Combusting propane produces CO2. Doing so with insufficient oxygen produces CO. I doubt that an enclosed boat would be oxygen starved, but I suppose it’s possible over time.

First you need to know the difference between CO and CO2 to figure it out. Since CO2 detectors are specialty devices, I suspect you mean CO. These use IR to detect so it’s possible other airborne elements are causing it to false.

Sorry, correct. It is a carbon monoxide detector, or CO detector only. But they're something that everyone keeps on their boat, so I'm not sure I understand how everyone doesn't encounter this issue. And I've worked on countless boats, and we never had issues with the alarms going off, so it's something on this boat.

 

Off gassing batteries will set off a CO detector. Are your batteries near it? Are they older batteries?

Mark

 

Not really. The batteries are under the pilot berth which is completely covered in stuff at the moment, and that is a separate cabin with the door closed.

 

Your stove may need to be cleaned. If the air and propane are not mixing properly, CO can be the result.

 

What color is the flame on the stove?

 

They're definitely blue.

 

I've heard of excessive amounts of steam setting off CO alarms: boiling water, shower? Also bad batteries in the unit causing false alarms.

 

Wouldn't be steam or water in this case.

 

Overly-sensitive or dysfunctional detector? I would get a hold of another detector from another boat -- one that isn't known to go off all the time. And, take yours onto another boat which doesn't set of their alarms.

CO is typically a product of incomplete combustion, so if it happens after, or during, running the main engine, or after cooking, you have the beginning of an answer.

There is not typically much CO in fart gas, so it's very unlikely to be that.

 

Overly-sensitive or dysfunctional detector? I would get a hold of another detector from another boat -- one that isn't known to go off all the time. And, take yours onto another boat which doesn't set of their alarms.

CO is typically a product of incomplete combustion, so if it happens after, or during, running the main engine, or after cooking, you have the beginning of an answer.

There is not typically much CO in fart gas, so it's very unlikely to be that.

These are new detectors and there are two. One went off minutes after the other, so I don't believe them to be faulty. Also, they read the CO level on the display, so I can watch it go up and down and track the area it's in. It moved from aft to forward, so I still suspect it's to do with the stove, I just don't know exactly what's happening and why it would be going off in the night hours after using it.

 

They are sensitive to hydrogen.

 

If you're totally convinced it's not a faulty detector, then I think Mark/Minn's ideas are the best possibilities. See if it tracks with charging. Perhaps your batteries need attention.

 

Was this the FIRST time you used the stove or the oven?

Had you just cleaned the stove or oven?

Where are you? Are you heating the boat and if so how?

 

They are sensitive to hydrogen.

Was this the FIRST time you used the stove or the oven?

Had you just cleaned the stove or oven?

Where are you? Are you heating the boat and if so how?

Not the first time using the oven, but first day with smoke/Co detectors on the boat. We've had this boat for a week and there were none on the boat.
Hadn't cleaned the oven, no. We had just used it, but detectors didn't go off until maybe 30 minutes after turning the oven off. Opened the whole boat up until the levels dropped throughout (these detectors have a numerical display for the ppm so I can watch it drop, and see where it's at a higher and lower concentration), but then again in the night the one in the V berth went off again (the batteries were out of the second one in the salon at that point because we thought we were in the clear).

My assumption, based on the first event, is that it's coming from back aft somewhere- probably the oven, maybe the batteries. The batteries ARE a few years old, but the area they're in is packed with stuff. These batteries have the special caps on them to prevent an explosion, should they not have proper airflow, but there is "some" ventilation.

We have a 16,000 btu marine air conditioner that we use daily right now, and we're in Florida, so it stays around 76-80 degrees F in the boat. It runs non-stop, usually. There is a diesel heater also in the boat and we did use it maybe 4-5 days ago, but haven't used it since.

 

My assumption, based on the first event, is that it's coming from back aft somewhere- probably the oven, maybe the batteries. The batteries ARE a few years old, but the area they're in is packed with stuff. These batteries have the special caps on them to prevent an explosion, should they not have proper airflow, but there is "some" ventilation.

If the batteries were on charge at the times this happened (or you are on shore power), I think looking at the batteries makes sense. As someone else said, cheapish CO detectors are very cross sensitive to H2, sometimes up to 2.5x. so a reading of 40 ppm CO might be just 15 ppm H2.

I know you said you have lots of stuff piled up around the batteries but H2 is not easily contained (definitely not by couch cushions). Maybe put an alarm in that cabin and see if it alarms in there too?

~f

 

My first thought the batteries off gassing. Is your battery compartment ventilated to the outside.
My second thought is ... Propane alone should not set off a CO detector but ...
Propane tanks in the cockpit ! Seriously ???

Safe Boat Propane System Installation

 

It's a 1976 Tayana and the propane locker is in the cockpit. But this isn't out of the ordinary at all. Many, many sailboats have propane in the cockpit lockers. They have ventilation holes and can breathe out there.

 

We have issues with our co detectors if the boat has been closed and humidity gets to high. We also have issues occasionally when the exhaust from boats nearby finds it's way in through open hatches. Never had an issue with the stove or lead acid batteries

 

Both times was pretty late at night, so not boats coming in and out. Surely it wouldn't be humidity... the AC runs ALL DAY (not by my choice hahah) so humidity levels aren't extremely high or anything, through it is Florida.

 

I appreciate your answering all our silly questions.

I have had a CO alarm go off due to outside sources. Once it was my diesel heater, we were at dock and there was a very slight wafting wind. It was enough to bring some gas ito te cabin.

I forget other circumstances.

You best option may be to monitor the alarms for some days, annoying as that may be. It is possible this was a one off weird occurrence. But if repetitive you may eventually see some pattern to it.

I would NOT ignore it.

I would consider purchasing a third detector, either similar or from a different store. Try to make sure the quality stamp shows a different lot. Mike ORiley's suspicion of a identical bad problems has merit. I had RayMarine send me a tiller pilot with a bad gyro. Then the replacement also had a bad gyro. EXACT SAME PROBLEM.
Not unheard of.

 

I appreciate your answering all our silly questions.

I have had a CO alarm go off due to outside sources. Once it was my diesel heater, we were at dock and there was a very slight wafting wind. It was enough to bring some gas ito te cabin.

I forget other circumstances.

You best option may be to monitor the alarms for some days, annoying as that may be. It is possible this was a one off weird occurrence. But if repetitive you may eventually see some pattern to it.

I would NOT ignore it.

I would consider purchasing a third detector, either similar or from a different store. Try to make sure the quality stamp shows a different lot. Mike ORiley's suspicion of a identical bad problems has merit. I had RayMarine send me a tiller pilot with a bad gyro. Then the replacement also had a bad gyro. EXACT SAME PROBLEM.
Not unheard of.

Ok, I'm going to get a Kidde, since they're known and reputable. Maybe that will help decipher what's going on next time it happens.
We do have a diesel heater but hadn't used it in a few days.
The alarms have gone off again in a couple of days! We use the stove daily, but haven't baked since that night. I guess if we bake something tonight we might know.

 

How about the possibility these are counterfeit detectors. Thats a real thing. Did you buy them online?

 

Oh gees. hahahah Alright alright! We will buy a Kidde as a control. haha

 

As a rule of thumb... have cabin ventilation at all times.
Have a CO monitor/alarm
Turn off gas at tank when not in use.
store tank in a compartment which drains over board

 

That's why I have Kerosene.

 

Okay....I have an idea!

This Device Turns The Stank From Your Farts Into Pleasant Smells For The Senses

Do you know someone who farts a lot? Save your friends and loved ones from utter embarrassment by giving them this Fart Filter Personal Flatulence Plug.

www.awesomeinventions.com

 

HAHAHAHAAHAH I'm legitimately going to take a look at that.

 

I love hearing that you purchased CO (with digital display) along with smoke alarms and posted this question. I’m thrilled so many boaters expanded on possible causes (i.e., acid battery off-gassing, exhaust leaks, propane locker leak, etc.). I had heard about a couple that initially thought the headaches and nausea they experience was from seasickness until they discovered that propane was leaking from the propane locker into their aft cabin where the propane pipe ran through.

To answer your questions on whether 90 PPM is dangerous, the “Fire Series: #1 Detection article“ has a CO PPM table and explains "continuous or intermittent exposure to carbon monoxide through your lungs and into in your bloodstream is cumulative over hours or even days. So even if you go out on deck or out for lunch for an hour or two, the carbon monoxide you inhaled is still in your blood. It takes four to six hours in fresh air to exhale about half of the inhaled carbon monoxide in the blood, starting from the last time of exposure."

So please continue to take the CO detection as seriously as you have and consider purchasing or borrow 1-2 more CO detectors with digital PPM displays to see if the additional CO detectors get the same reading or if the initial CO is faulty. I have lent my CO detectors to fellow boaters who have experienced the same issue many times.

We sail almost year-round on our 39’ sailboat, so we literally have 2 CO detectors in every cabin.

 

I love hearing that you purchased CO (with digital display) along with smoke alarms and posted this question. I’m thrilled so many boaters expanded on possible causes (i.e., acid battery off-gassing, exhaust leaks, propane locker leak, etc.). I had heard about a couple that initially thought the headaches and nausea they experience was from seasickness until they discovered that propane was leaking from the propane locker into their aft cabin where the propane pipe ran through.

To answer your questions on whether 90 PPM is dangerous, the “Fire Series: #1 Detection article“ has a CO PPM table and explains "continuous or intermittent exposure to carbon monoxide through your lungs and into in your bloodstream is cumulative over hours or even days. So even if you go out on deck or out for lunch for an hour or two, the carbon monoxide you inhaled is still in your blood. It takes four to six hours in fresh air to exhale about half of the inhaled carbon monoxide in the blood, starting from the last time of exposure."

So please continue to take the CO detection as seriously as you have and consider purchasing or borrow 1-2 more CO detectors with digital PPM displays to see if the additional CO detectors get the same reading or if the initial CO is faulty. I have lent my CO detectors to fellow boaters who have experienced the same issue many times.

We sail almost year-round on our 39’ sailboat, so we literally have 2 CO detectors in every cabin.

Thank you! It went off again last night, both of them in the middle of the night, we hadn’t cooked, there were no boats moving around outside… AND we left town today and the marina just called and said they were going off right now and someone just called the marina.
we bought these off Amazon, and I trust the Kidde brand but I can’t find a good one with the display. Is there a brand you recommend that has the display?

 

To add, while leaking propane will not be detected by a CO monitor, they do make raw propane detectors too. Really smart idea to have them positioned where a leak might go. Propane is heavier than air, so a hose leaks by gravity. CO rises, a bit. Wafts is probably more appropriate.

 

Yeah the propane lives on the propane locker in the cockpit and there is proper low ventilation for that, but having something like that in the galley would be smart!

 

Good morning, Consider purchasing a hand held CO detector that are available from Amazon for less than $40. Not lab quality but you'll find the problem in a few minutes. I suspect incomplete combusion on the oven.
Good luck and be careful, this is a bid deal.

 

To add, while leaking propane will not be detected by a CO monitor, they do make raw propane detectors too. Really smart idea to have them positioned where a leak might go. Propane is heavier than air, so a hose leaks by gravity. CO rises, a bit. Wafts is probably more appropriate.

Good morning, Consider purchasing a hand held CO detector that are available from Amazon for less than $40. Not lab quality but you'll find the problem in a few minutes. I suspect incomplete combusion on the oven.
Good luck and be careful, this is a bid deal.

Is that still possible even when we haven’t been using the oven?

 

The two posts you quote with this reply were referring to different things. Mine to raw propane leaks (explosive risk), the other to CO. It is possible to get a propane leak, when you're not using the stove, if you fail to shut the tank off in its locker. I always found it to be the safest practice to shut the gas off, while the burner was ignited to reduce the pressure in the hose. Even with the tank closed, the gas in the hose could theoretically leak, but I do not think it's all that much.

Before I overstate the explosive risk, from raw propane, it's extremely uncommon. Your boat sound like it's had some deferred maintenance, with prior owners, so maybe a higher risk.

 

Have you tried to take a measure inside the battery box?

If it's not incomplete combustion, and it's not from the outside, and it's not a faulty detector (I'm still not convinced it's not), then what is left? Seems to me it has to be H2 production from the batteries. It's also possible to have H2 production from arcing electricity, so a bare short somewhere, but that wouldn't produce much.

 

Have you tried to take a measure inside the battery box?

If it's not incomplete combustion, and it's not from the outside, and it's not a faulty detector (I'm still not convinced it's not), then what is left? Seems to me it has to be H2 production from the batteries. It's also possible to have H2 production from arcing electricity, so a bare short somewhere, but that wouldn't produce much.

It does always start “near” the batteries, because the batteries are under the pilot berth and the alarm is at the nav station just forward of that. Today I’m going to move one into the pilot cabin and then keep the one at the nav across from the galley and then see which one goes off first. That will tell us a lot!
I ordered another one that will arrive tomorrow and it’s a Kidde with a display.

 

Buckle up.
Sometimes these things work out and sometimes not.
MybWife and I are an odd couple, se would never have left the dock, ever. Yet here we are as live aboard in Caribbean in season.

People are odd as can be, and there is no telling what works and what does not between us.

Goeed lunch however it goes.

 

If the muffler is leaking, your bilge pump will take care of the water, but the CO will be trapped in the boat. Go below with engine, and genset running and inspect to see if there is any leaking.

 

There’s no generator and it happens when we haven’t been running the engine. We did run the engine yesterday in the morning but those alarms didn’t go off until the middle of the night last night. The other times, I don’t think we’d ran the engine.

 

How " good luck" becomes "goeed lunch" I will never know.

Better luck with your mystery.

 

Well I understood it anyway! Hahah