I'm Having Carbon Monoxide Problems - Any Ideas??

[theothersully]

Carbon Monoxide is a product of combustion of organic fuels at high temps with restricted oxygen. a wood stove can have levels as high as 5000 ppm in the flue. Danger levels begin around 70 ppm. and death at 1600ppm. My home detector is digital and records levels around 10- 24ppm. I heat with wood and also oil fired forced air. I have been recording these levels for years, since installing the detector. Do you have a generator? a propane stove will give levels of 5 - 30ppm. Do you have a fresh air intake for your stove?

This is a helpful sanity check. So you see levels of 10-24ppm often as well?

I mean these certainly don't *seem* dangerous and really aren't as far a getting deathly ill go, but I wonder about long term exposure.

Or... is this just new information on account of these digital readouts and we *all* have been breathing these levels for many years?

Yes, it's surprising how much CO a propane cooktop stove gives off... more than the wood stove... up to 30ppm, just like you said.

No fresh air intake on this stove. It's a simple firebox going to single wall flue/chimney. Combustion air comes from the room, which, in turn, comes from all the cracks and air leaks around the boat.

 

[deadon]

I have been burning wood since 1977 and only installed the digital CO detector in the past couple years. My guess is, and it is only my guess, that I have always had these levels. Just no way of recording until the digitals came out. I have had other detectors but they were not digital and the levels never reached a level to activate the alarm.

 

[theothersully]

I have been burning wood since 1977 and only installed the digital CO detector in the past couple years. My guess is, and it is only my guess, that I have always had these levels. Just no way of recording until the digitals came out. I have had other detectors but they were not digital and the levels never reached a level to activate the alarm.

Yeah, that's kind of what I was thinking as well.

I had a standard CO detector without readout on the old boat (in the first year I used this stove) and it never went off.

Now that I have these digital readouts, it seems I'm watching them all the time. It's not enough to set an alarm off, but there's always elevated CO. The only time there isn't elevated CO (up to 24PPM) is when it's very windy. My damn drafty windows probably are airing the place out nicely under those conditions! ha ha

 

[oconnor]

Try this for a test - shut the stove down, and set up a small fan to vent the same amount of air from the cabin - you are talking about 25 CFM, not much more. A small muffin fan from a PC blowing out your flue should do it. If you are drawing CO up from below decks etc, then it won't change based on stove fired or stove cold. Try it for a couple of hours and see if you get a change. At least then you can eliminate or incriminate the stove.

You may not get the CO without the controlled venting. To little vent and you may not draw from the trouble source, to much and you may dilute it down, so try to mimick the stove behavior without the fire.

Just a crazy thought.

 

[karri0n]

That's pretty ingenious, O'Connor.

 

[TMonter]

Another thing to try is seal the pipe elbows with Rutland black stove cement (from the inside)after cleaning them.

 

[theothersully]

Another thing to try is seal the pipe elbows with Rutland black stove cement (from the inside)after cleaning them.

This is a good ideal. In my experience, the stove cement is brittle and cracks very easily. How will they stay sealed once I start moving the elbows around?

PS: I'm getting frustrated over here. Lit the fire tonight, CO went immediately up to 17. Thats my usual number. It had been at 0 all day today while I was sealing up every little nook I could with Rutland stove cement.

I'm about at my wit's end here. I could even smell the most faint whiff of smoke a few minutes ago for a brief moment.

Is there any reason a galvanized stove elbow would leak as compared to the standard indoor black-painted ones? I am wondering if I should go pick up new stove pipe and elbows tomorrow.

Either way, this whole thing is getting pretty time consuming.

Also I'm going to contact the stove manufacturer.

 

[oconnor]

PS: I'm getting frustrated over here. Lit the fire tonight, CO went immediately up to 17. Thats my usual number. It had been at 0 all day today while I was sealing up every little nook I could with Rutland stove cement.

I'm about at my wit's end here. I could even smell the most faint whiff of smoke a few minutes ago for a brief moment.

Is there any reason a galvanized stove elbow would leak as compared to the standard indoor black-painted ones? I am wondering if I should go pick up new stove pipe and elbows tomorrow.

Are you using galvanized pipe? From my reading, that is a bad idea, as the galvanized will off gas, and can make you quite sick.

I'm not sure if galvanized components in the flue would affect the CO meter (anyone else have an idea?), but its not a good plan. Here is the wiki article https://www.hearth.com/econtent/index.php/wiki/Galvanized_stove_pipe_-_NO

If you aren't using galvinzed, then just ignore this, except to remember not to use galvanized steel smoke pipe.

 

[Shari]

Okay, it's "coming" from somewhere on the stove.... Take a wooden match or incense burner and hold it around various areas of the stove itself. See if or where the match or incense wavers and that should be your leak. Is your stove gasketed? Maybe a leaky gasket??? The only other thing I can think of is your stove is pulling air from below decks. Is there anything down below decks that could cause this CO????

Keep posting, Tom Sawyer, there's lot of knowledge (not me though) here on this message board.

(edit: Test is done when the stove is burning.)

Shari

 

[theothersully]

Yes, Brent. I *do* have galvanized pipe. However, I burnt off the zinc oxide when I first installed the pipe quite some time ago. To my knowledge, the galvanized pipe (and other galvanized things being welded and such) form zinc oxide, much of which goes into the air as a "smoke" while they are being heated. After heating the initial time, there is no more "smoke" or metal gas that comes off the pipe.

Welders often become sick from breathing the zinc oxide and get what's known as "metal fever." I know CA has publications talking about never using galvanized pipe indoors. I've read those.

I did a lot of research into this and found that *all metals* actually do this.

My other choice in metal was stainless steel. It turns a nice, colorful patina when first heated, giving off a metal oxide of its own.

So, to my knowledge, there hasn't been any zinc oxide gas put off from the pipe since the day I installed it and fired it up to glowing red.

One interesting change:

I removed the smoke head (chimney cap?) from the chimney and it has greatly reduced the CO output. It took a very long time to reach 12ppm (on the order of hours). It had been reaching 17ppm in 15 minutes before. This idea came from the stove's manufacturer. A bad smokehead could be *part* of the problem, but definitely seems to show that this is related to draw...

Removing the smokehead would have created a little more draw.

PS: I'm getting frustrated over here. Lit the fire tonight, CO went immediately up to 17. Thats my usual number. It had been at 0 all day today while I was sealing up every little nook I could with Rutland stove cement.

I'm about at my wit's end here. I could even smell the most faint whiff of smoke a few minutes ago for a brief moment.

Is there any reason a galvanized stove elbow would leak as compared to the standard indoor black-painted ones? I am wondering if I should go pick up new stove pipe and elbows tomorrow.

Are you using galvanized pipe? From my reading, that is a bad idea, as the galvanized will off gas, and can make you quite sick.

I'm not sure if galvanized components in the flue would affect the CO meter (anyone else have an idea?), but its not a good plan. Here is the wiki article https://www.hearth.com/econtent/index.php/wiki/Galvanized_stove_pipe_-_NO

If you aren't using galvinzed, then just ignore this, except to remember not to use galvanized steel smoke pipe.

 

[theothersully]

Hi Shari,

Thanks for the idea. This was an idea the stove manufacturer suggested as well. He suggested using an incense when the stove was off to check and be sure no air was coming down the chimney. He said the only way I can get CO into the main area of the boat (outside the stove's firebox) would be to have negative pressure canceling out the draft effect, even momentarily.

I will try this technique while the stove is on as well, as you suggest. The stove is not gasketed. The loading door fits snugly.

Just to clarify... for those who don't know the layout of a typical recreational boat... there is no "below decks" in the way you are mentioning. Well, there technically is a below decks, but the entire living area is "below decks." The deck iron goes through the deck to the outside. I'm "below decks" as is the wood stove, my galley (kitchen), living room area, bathroom, bedrooms, etc... Everything comfortable is below decks. The snow in the picture, my wood and my chimney are "above decks."

Hope that helps...

Edit: Good test! I was able to confirm that every little crack and joint on my stove was sucking air *in*. If I held the flame next to the crack, it was pulled inward to the inside of the stove. This is good. This means no CO was escaping in the moments when I was doing the match test. I will try the match test in the AM before I re-light the stove.

Also, I did perform this test without the smokehead on, so it may have been this smokehead.

I got a reading no higher than 12 in two stove loads of wood and *only* on one detector! I have one on each side of the boat. The one closest to the stove is now stuck at a persistent 12 and the other on the other side is at zero! Previously, both read similar 17-24 numbers. I'm wondering if the 12 is just from me opening the door to load some wood in...

Okay, it's "coming" from somewhere on the stove.... Take a wooden match or incense burner and hold it around various areas of the stove itself. See if or where the match or incense wavers and that should be your leak. Is your stove gasketed? Maybe a leaky gasket??? The only other thing I can think of is your stove is pulling air from below decks. Is there anything down below decks that could cause this CO????

Keep posting, Tom Sawyer, there's lot of knowledge (not me though) here on this message board.

(edit: Test is done when the stove is burning.)

Shari

 

[begreen]

sully, is there a screen on the cap? If the cap is plugging up, draft will be reduced. If it looks clean, try adding 2 ft more pipe to increase draft.

Usually sailboats are sealed very tightly because on the ocean you never know when you are going to take on a serious wave. Have you tried leaving the companionway door ajar or a cabin light slightly open to see if that improves things?

 

[theothersully]

sully, is there a screen on the cap? I still think this may be related to draft. It the cap is pluggin up, draft will be reduced.

I think you're right.

There is no screen. I took that cap right off earlier and saw major reductions in CO. None on the detector farthest from the stove and 12ppm on the detector right next to the stove.

I think the cap had bad airflow and I need to try another one. That was the stove manufacturer's first suggestion as well when he saw that cap.

I'll post some more results tomorrow.... when I have more data. For now, it seems reduced, anyway.

Edit: Damn. I take it back. I *was* looking good. Now both detectors are reading 13ppm and 11ppm. Maybe Shari's match trick elevated it? It *is* a really small space.

Yes, I have tried leaving various hatches open. Of course, the CO clears out completely when I open one that creates positive pressure, and my precious heat clears right out with it! ha ha Currently, the way the boat is facing, I am facing into the wind. If I open the companionway (main door for those not familiar with boats), this creates a negative pressure, as the companionway is the most downwind thing I can open.

But yes, certainly opening a hatch which creates positive pressure pumps a lot of new air in and gets rid of any CO (mostly, I think, because the air in the boat changes with the outside air).

 

[begreen]

Try adding a length of pipe as a test. It can be galvanized for testing purposes and will be cheap.

Where is the combustion air being pulled from? The companionway?

 

[theothersully]

Try adding a length of pipe as a test. It can be galvanized for testing purposes and will be cheap.

Where is the combustion air being pulled from? The companionway?

Can't hurt. I'll give that one a shot too. I'll increase my outside chimney to 8' on deck.

The combustion air is (to the best of my guess following the air flows) coming from the poorly sealed windows or "ports" I have. I have Eight 1ft x 1ft opening windows that seal so poorly you can feel a little wind coming in when you stick your face near them to look out.

My theory was to leave them a bit "leaky" so as to allow air to flow into the boat to replace air that had gone up the chimney. They are also evenly placed all around the boat on both sides, which prevents negative pressure building if they were all located downwind or something. There are as many one one side as the other.

Also, the companionway is very tightly sealed up because it was causing negative pressure under strong winds when I first installed the stove.

It had a nearly 1/8" gap all the way around, which I weatherstripped to make air-tight.

What's really confusing is that the windier it gets, the *better* the stove works, all the way down to no CO leaked. Tonight is nearly still air, and it's dumping CO into the boat at a decent clip still (up to 15ppm as of now... just opened up the hatches again and am losing my heat)

Can poorly seasoned wood cause this?? I have some pretty green stuff I've been burning. It gets hot, but it's a difficult burn. This problem seems to have coincided with my switch to this wood. Maybe burning good wood is another test...

 

[Shari]

Sully,

Try that same match test all along the chimney, from the exit on the back of the stove all the way up to the ceiling. You should have some type of connector in the ceiling, test that area also. Do this with the stove burning. Post results back here on the list.

Shari

 

[theothersully]

Done. I couldn't find any spot where there was any exhaust gas coming out of the chimney or stove. In fact, wherever there was a crack, it sucked the match flame *in*, showing that perplexingly... the CO is not coming from the stove??

I tried:

1) Taking down part of that extra long chimney so the ratio of inside
chimney to outside chimney was good. I left only a 2' section outside.
Same CO result.

2) Using matches (I have no incense today and my wife won't be back
with the car until tonight), I checked and verified that air was going
into the cracks around the door of the stove, the vent and even the
elbows of the chimney. Yet... same result! 17ppm right now.

3) Tried running with a window entirely open. Same result! 13ppm.

There is no wind at all today.

I have very good results when it's extremely windy. Is that a clue? Is
it maybe somehow coming *back* inside from the chimney? Ever heard of
that?

I am really *really* stumped. I've been working on this for two days
straight, neglecting regular work because it's unhealthy to sit in
carbon monoxide like this.

Has anyone ever heard of CO that is exiting a chimney properly coming back into a living area?

Sully,

Try that same match test all along the chimney, from the exit on the back of the stove all the way up to the ceiling. You should have some type of connector in the ceiling, test that area also. Do this with the stove burning. Post results back here on the list.

Shari

 

[Adios Pantalones]

1) it may be coming from another appliance. 2) consider that your CO detector is wrong.

 

[Shari]

[quote author="theothersully" date="1229716206"]Has anyone ever heard of CO that is exiting a chimney properly coming back into a living area?

Sully,

Is your chimney exhaust being sucked back in your windows which are on the same side of your boat as your chimney?

Shari
(who is taking a break trying to shovel out from 12" of snow!)

 

[theothersully]

1) it may be coming from another appliance. 2) consider that your CO detector is wrong.

I just want to emphasize that I don't *have* other appliances. All propane is shut off from the tank, even my water system is winterized (I jug the water in). There are no other appliances on except a microwave, toaster oven and an electric heater.

Any and all "dirty boat stuff" (engines, batteries, chargers, fuel, etc...) is all located in a completely different space that is air/water tight to the living space. There are 6 individual compartments that are all completely air/watertight to each other, fiberglassed of from each other. No water, no fumes, no nothing can get between the areas.

In any case, if I stop the wood stove, the CO stops. When I light it, the CO is right back to 17ppm average. I can repeatedly open up the boat to air it out, then fill the boat back up with CO by running the wood stove. When I use the little electric heater, there is no CO at all. Zero on the meter. Also, I don't only have one meter, I have two... both made in 2007.

Thank you very much for thinking of whatever outside the box stuff you can... I'm literally losing it here, having to work on this instead of work for two days now.

 

[theothersully]

Has anyone ever heard of CO that is exiting a chimney properly coming back into a living area?

Sully,

Is your chimney exhaust being sucked back in your windows which are on the same side of your boat as your chimney?

Shari
(who is taking a break trying to shovel out from 12" of snow!)

This is what I was thinking... my latest theory. It *does* seem to fit with the idea that when the wind picks up, my CO goes away.

Later today (when my wife returns) I will go to the hardware store and put some extra lengths of pipe up to make the outside chimney go up 12', which should keep smoke away from all the windows.

Anyone else think this is likely?

 

[karri0n]

I think you just aren't getting quite enough draft. The fact that when you removed the cap your CO went down confirmed it, at least in my mind. Add another 2-4' or so of pipe, and it should solve the problem if it's actually venting back in or not drafting strong enough. If you can vent outdoor air to that stove, with an OAK or fabricating one yourself, it might be worth doing too. That will also improve any leakiness of the cabin.

 

[sl7vk]

Where do you store your wood?

 

[theothersully]

Where do you store your wood?

Hmmm... interesting angle. It's outside on deck. My curiosity is piqued.

 

[sl7vk]

Where do you store your wood?

Hmmm... interesting angle. It's outside on deck. My curiosity is piqued.

Sorry, I was going off topic on you. I was just curious how you obtain and store your wood..... Takes up a lot of space even when you have solid land to store it. Sorry nothing to do with the CO.

My opinion is that your problem is draft related. You can have tons of cracks in your pipes, if that thing is drafting, there is no smoke that will leak. I would add 3-4 feet of stovepipe, and get a decent cap. I'd then make sure I didn't turn the damper down early....

If your draft is strong enough, you should be able to run the stove with the door wide open without leaking smoke.

Your run is short, and it isn't insulated, so your draft is weak.

I love your set up though, so long as none of your neighbors "borrow" from your wood pile.