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

[theothersully]

Hey Everyone,

First post on the forum. I joined because I absolutely love heating with wood and have a question.

I used to have a wood stove in the house I grew up in as a child... it was primary heat and I'm very used to using one.

A few years ago, I got a wood stove as primary heat for my current home. My current home also happens to be a boat. Yes, I live on a boat.

I have had this stove on two different boats in the few years I've had it.

History:

The stove is a "Little Cod" (Google it if you want). It's a great little stove, putting out 29,000BTU, which keeps my boat warm. It's installed with single-wall metal stove pipe going from the stove to a "deck iron", which is the point the chimney exits the deck. The "deck iron" is filled with water and keeps the hot chimney from melting the fiberglass hull. Pretty cool, huh?

Above the deck, there is a 6' chimney with cap to keep rain out.

In the other boat, I had a CO detector, but without digital readout. The other boat was set up in a similar fashion with the same type of stove. I never had a CO alarm go off on the other boat.

The Problem:

When using this stove on my current boat at the beginning of this season, I had a CO reading of zero on my detectors (I have two since a boat is a small, confined space). Lately, I have been getting readings between 13PPM and 24PPM inside the boat ALL THE TIME when the stove is on.

I'm in here all day long because I have an internet business. I'm exposed to this level of CO all day and night 24/7.

Today, when lighting the stove, I noticed a little puff or two of smoke coming out of my elbow joint above the damper. It only seemed to happen when I lit the stove, but got me wondering if that's where my CO is coming from.

You can't smell any smoke inside the place.

Also, I don't get CO readings on extremely windy days, only when it's very still out.

What I've Done:

1) Wrapped the elbow with aluminum foil very tightly to try and seal any cracks in the joints

2) Tried running the stove with the damper more open and the vents more closed than normal to create "suction" inside the stove

3) Cleaned out the chimney 100% (it comes apart, so it's easy to do)

I just can't figure out why this is happening! Any ideas? I mean I can't smell a bit of smoke in here... I just keep getting readings, on both CO detectors of 13-24PPM all the time! I'm getting very frustrated!!

Do you think I had this kind of CO exposure all the time in the past, before I got the alarms with the digital readouts? It's never been bad enough to set off an alarm, but the constant low level exposure seems like it can't be too healthy. Is this normal??

 

[savageactor7]

You live on a boat in NH? I'd forget about wood heat...in that air tight set up CO can put you in the snap of a finger. Get one of those electric fluid radiator heaters and live to collect your SS.

 

[theothersully]

You live on a boat in NH? I'd forget about wood heat...in that air tight set up CO can put you in the snap of a finger. Get one of those electric fluid radiator heaters and live to collect your SS.

Thanks for the reply.

I appreciate your concern, but I'm not afraid of my stove producing lethal amounts of CO. The stove doesn't back up. Since you can't smell smoke when it's operating, and you hear a constant roaring/whooshing of air going up the chimney, it can only be *sucking* air from my living space, as a properly designed and operating stove does.

I've been heating with wood for 3 years aboard and there has never been a dangerous amount of CO produced by the stove. I'm dealing with a nuisance level that only shows up because I have the digital readout now.

It's likely that I was happily breathing this same level the entire first 2 years.

In all actuality, the propane cook top I use in the summers (when not cooking on the wood stove) produces far more CO - upper 20's to 30PPM.

 

[karri0n]

I agree with SA on this one, confined spaces can be dangerous if you forget the air vent one day, or get a load of not so great wood, etc. If you're dead set on wood heat for your boat, I would imagine adding a few feet to your chim to improve draft couldn't hurt. Other trick would be to try getting some high heat insulative tape (such as header tape, not sure if they make it in bigger rolls for chimney use) and put it around the pipe to increase flue temps and seal it a bit better.


A really thorough inspection of the stove, connector, and flue might also give you a better idea of where the leak could be coming from. I say just take a good hard look at all areas of the exhaust for the stove, from the hole, up, and out.

 

[theothersully]

I agree with SA on this one, confined spaces can be dangerous if you forget the air vent one day, or get a load of not so great wood, etc. If you're dead set on wood heat for your boat, I would imagine adding a few feet to your chim to improve draft couldn't hurt. Other trick would be to try getting some high heat insulative tape (such as header tape, not sure if they make it in bigger rolls for chimney use) and put it around the pipe to increase flue temps and seal it a bit better.

Actually, there is no dedicated vent at all, other than the natural cracks and whatnot that allow ample air in to allow the chimney to work properly. Again, I've never had any major levels of CO in here in 3 years, running the stove all fall, winter and spring.

My chimney is 6 ft above the deck, which is well above the "roofline". It's the largest marine chimney I've ever seen... most are 2-4ft above the deck. I actually can't go any higher because it gets too "tippy" as the boat rocks.

EXCELLENT idea about the high heat tape!! I'll have to look that up. At least that would eliminate one possible source of leakage..

 

[karri0n]

Sorry, by air vent, I meant the air control on the stove. As in, if you dampered down too early, etc.

 

[theothersully]

Sorry, by air vent, I meant the air control on the stove. As in, if you dampered down too early, etc.

Gotcha... thanks.

I have been dampering down kind of early lately to try and run efficiently. I wonder if you're onto something there.

I will go "back to basics" as you said in the earlier post as well and check every little possible way that any leak can be happening.

Thanks for the info.

 

[karri0n]

Have to ask an expert on the subject about the 20-30 PPM, as I am far from an expert on what constitutes a harmful level over a long duration.

 

[Shari]

Okay, I just have to say this: I want to see a picture of this! Living on a boat with wood heat??? Tom Sawyer's visage in 2008! Awesome lifestyle!

Shari

 

[theothersully]

Okay, I just have to say this: I want to see a picture of this! Living on a boat with wood heat??? Tom Sawyer's visage in 2008! Awesome lifestyle!

Shari

You got it.

For privacy reasons, I won't show my personal setup, but here is a link to several pictures of people using the type of stove I am using:

http://www.marinestove.com/installation_views.htm

Some of these installations are, of course, land based, but the stoves are primarily designed for marine use.

The attached picture is my favorite one from this gallery... this guy is the best character ever!

 

[karri0n]

Sully himself, of course, has a much bigger beard, a pegleg, and an eye patch.

 

[moondoggy]

Okay, I just have to say this: I want to see a picture of this! Living on a boat with wood heat??? Tom Sawyer's visage in 2008! Awesome lifestyle!

Shari

yea me too, and a pic of the deck iron.
be safe man, check joints, check with someone who knows these meters, sleep with the window a crack.

 

[Shari]

Sully himself, of course, has a much bigger beard, a pegleg, and an eye patch.

Just as I pictured him - but you forgot about the gold earring in one ear... :coolhmm:

Shari

 

[theothersully]

Okay, I just have to say this: I want to see a picture of this! Living on a boat with wood heat??? Tom Sawyer's visage in 2008! Awesome lifestyle!

Shari

yea me too, and a pic of the deck iron.
be safe man, check joints, check with someone who knows these meters, sleep with the window a crack.

Long Island and a wood heat?? Wow. Not all that common there.

I spent one of the 3 years I've been running this stove on boats wintering over in Manhasset Bay (Port Washington).

Here's a picture of the deck iron:

 

[theothersully]

I don't know if I should start a new thread about this, but it *is* part of hunting down this CO problem...

karriOn mentioned a bad load of wood. I'm burning some oak I cut at a farm in central NH. The oak is far more green than that I normally burn, which makes for an annoying fire to keep. It doesn't light as easily, some of the logs hiss steam out and I find I have to keep more "flow" over the logs by venting more and keeping the damper open more than normal.

Is this something that could be making me get some CO in the room now? I didn't have any CO earlier in the fall when I was burning a different batch of wood.

Just trying to come up with ideas... I am messing with the chimney and re-cementing anything I can find that might leak, as well as putting on a new gasket today.

 

[begreen]

I'd get the tape off the elbow. You are just cooking the adhesive and adding to the interior air pollution.

This sound like it could be a draft issue. Is the pipe properly sized for the stove? Perhaps you can find an unjointed elbow that will be tighter and add an extension piece to the upper flue? Can you post a shot of the stove itself including the flue? Nice little boat stove btw.

 

[Adios Pantalones]

What might have changed between the last boat and this one is draft. Is there any horizontal run of pipe? Is the boat less drafty than the last one?

 

[theothersully]

Thanks for the help, everyone. This new boat is indeed more "tight" than the last one. It has very few areas that are open. There are eight 1ftx1ft windows that leak enough air that you can feel it blowing on you as you put your face up to them too look out. Everything else is extremely well sealed off, including the main door, which I weatherstripped in order to prevent a negative pressure I was getting when that door was downwind.

Here are the photos of the stove, flue and outside chimney. To h#$% with privacy... I need to reduce the CO! ha ha

Please excuse the horrible mess of ashes and the fact that I'm due for a stove blacking soon. Making that area pretty has fell to the wayside as I've been busy working on a new small business.

The aluminum foil was put there this AM in a half-hearted attempt to see if I could stop any leaks from the elbow. I have a nearly straight flue with hardly a 10 degree offset. Very much a straight line up 10 feet total. The pipe is 4", which is what the stove manufacturer specifies and sells with this stove.

The flue and chimney are the same pipe, .26 galvanized. I burned off all the zinc oxide by running it cherry red (momentarily) with all the windows and doors open when it was first installed.

Outside, I have creasote leaking because this pipe was a temporary galvanized pipe while I waited for stainless. The M.F/M/F pipe fittings out there added up from the deck iron to the little chimney cap in such a way as I had to install them upside down. The cap is female and the deck iron is male. So... it's leaking a bit. I will do something different next winter with that issue.

 

[moondoggy]

awsome view man. love the deck iron.
foil tape...
http://www.amazon.com/mil-REFLECTIV..._3?ie=UTF8&s=automotive&qid=1229626036&sr=8-3

 

[Dill]

So your on the PNSY side of the river? Cool. (not that I want to to put out your personal info but we only have some much saltwater in NH.)

 

[theothersully]

So your on the PNSY side of the river? Cool. (not that I want to to put out your personal info but we only have some much saltwater in NH.)

That's OK. I'm here 24/7 and if there are any internet psychos that stop by, I *am* a gun toting maniac, so... they won't have any fun visiting with me anyway.

 

[Corey]

First, if the stove is tight, are there other sources of CO on or around the boat...cook stove pilot lights, generator exhaust, cigarette smoke, gas water heater, backup gas furnace, other boats with flues/exhaust, etc. It could be that the CO is not necessarily coming from the stove, but the extra draft and negative pressure created when the stove is in operation is causing some other flue or exhaust to reverse flow, or possibly pulling air from a generator/engine room which may contain a higher % of CO.

Secondly, are there other chemicals around which may trigger a false alarm?...(http://www.ul.com/consumers/co.html) UL 2034, the Standard UL engineers and technicians use to test residential carbon monoxide alarms, includes exposure tests to normal concentrations of methane, butane, heptane, ethyl acetate (nail polish remover), isopropyl alcohol (rubbing alcohol), carbon dioxide and propane -- all gases that would typically be found in a home. You should, however, keep these chemicals away from your CO alarms. Low exposure over an extended period of time could damage the sensing device and cause your alarm to sound a false alarm. I would also expect since many of these chemicals are hydrocarbon based, additional hydrocarbons such as gasoline and/or diesel fuel vapors would act in a similar manner.

Third, what is the age of the detectors? I think the lifespan is generally considered to be 3-5 years. Outside this range, and the potential for false alarms and/or inaccurate readings would probably go up significantly. Info below seems to indicate 2005 and later detectors are prohibited from reading below 30ppm, so these may be entering the 3-5 year range?

Also of note: http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_002.cfm

Changes In Test Standards

The standards organizations of Canada (CSA) and the United States (Underwriter's Laboratory or UL) have co-ordinated the writing of CO standards and product testing. The standards as of 2005 prohibit showing CO levels of less than 30 ppm on digital displays. The new standards also require the alarm to sound at higher levels of CO than with previous editions of the standard.The reasoning behind these changes is to reduce calls to fire stations, utilities and emergency response teams when the levels of CO are not life-threatening.This change will also reduce the number of calls to these agencies due to detector inaccuracy or the presence of other gases. Consequently, new alarms will not sound at CO concentrations up to 70 ppm. Note that these concentrations are significantly in excess of the Canadian health guidelines.

Carbon Monoxide Concentrations

CO concentration in parts per million (ppm) Effects
0-2 Normal conditions in and outside Canadian houses.
11 Maximum tolerable indoor concentration over an eight-hour period.1
25 Maximum allowable concentration for continuous exposure for healthy adults in any eight-hour period.1
30 CO detectors must not sound alarm within 30 days.2
70 CO detectors must sound alarm within one to four hours.2
150 CO detectors must sound alarm within 10 to 50 minutes.2
200 Slight headache, fatigue, dizziness and nausea after two to three hours. CO detector alarm must sound within 35 minutes.3
400 CO detectors must sound alarm within four to 15 minutes.2
800 Dizziness, nausea and convulsions within 45 minutes, death within two to three hours.3
1600 Death within one hour.3
13,000 Danger of death after one to three minutes.3

 

[moondoggy]

dang corey you kick ass.

 

[deadon]

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?

 

[theothersully]

That is a *great* post, Corey. Thank you for taking the time to put together that information. It is very useful to anyone who has CO issues.

I have looked up the exposure levels and 17-24PPM (which I seem to have 24/7) does make me wonder, as all the exposure levels speak to 8 hours days and OSHA working conditions. This is 24/7... all the time.

(So I apologize for any incoherent postings... ha ha)

Seriously, the level is so low that I'm thinking these level happen to a lot of people. My detectors were purchased 1 yr and 1 month ago at Lowes hardware store. They were brand new (in the box) Kidde units. Date of manufacture stamped on the units is: February 28, 2007.

On a boat, there are often various chemicals that can set off CO detectors. It's a life full of false alarms. While here this winter, we have nothing running. The entire boat is "winterized" which means we have no chemicals present, no fuels, no engines or gensets running, no sources of CO at all. We actually turn off the propane in the winter because we do not like the levels of CO the oven and stove put out - levels much higher than the levels my wood stove seems to be putting out. In the summer we open up the boat to cook. Not so pleasant in the winter, so we cook on the wood stove and in a small electric oven. (sometimes we throw a potato in the wood stove too... yum!)

Anyway, there are no sources of possible false alarm gasses in the winter except one:

I have styrene insulation laid down on the floors. It helps keep the feet warm. This insulation is comprised of bubbles of HFCs, which are known to set off CO detectors. I did an experiment though... I spent 5 mins crushing up and popping the cells of a piece of insulation within 1/4" of CO my detector's sensor. This *should* have released enough HFCs to at least register a blip. It did nothing.

So... yes, that is the only wildcard I have in this setup. Of note, if I have the stove off and an electric space heater running, I have a steady zero PPM on the meters. Only when the stove runs do I get readings.

Again, thanks for a very thoughtful post... very helpful.

First, if the stove is tight, are there other sources of CO on or around the boat...cook stove pilot lights, generator exhaust, cigarette smoke, gas water heater, backup gas furnace, other boats with flues/exhaust, etc. It could be that the CO is not necessarily coming from the stove, but the extra draft and negative pressure created when the stove is in operation is causing some other flue or exhaust to reverse flow, or possibly pulling air from a generator/engine room which may contain a higher % of CO.