CO2 alarm goes off, when burning on "low" T stat

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bogydave

Minister of Fire
Hearth Supporter
Dec 4, 2009
8,426
So Cent ALASKA
Lately I had a problem when burning my BK on the low settings.
I would get flu odors & a few times even set off the
CO2 alarm when burning on the low settings.
I just brought in some dry spruce, & it is 40+ out side & have had trouble
with the house getting too warm. (75°+).
I was thinking the lower btu wood spruce would burn cooler.
I was still getting the house too warm & decided to turn the T-stat down &
watch it. It went into what I call the "smolder mode" (1) but kept a good glow of
hot coals. No smell or draft issues, all day (so far)

With this success I checked my birch & fond some only 1 yr old seasoned stuff in the inside wood box.
I thought the 1 year old birch was well seasoned but when I compared it to some 2yr + seasoned birch,
same size splits, the 1 yr old stuff was heavier. Sounds different when dropped also.

I "assumed" 1 yr seasoned birch was dry, but it appears it may be similar to what I've read here
about "Oak" needing 2 yrs + to dry well.

I have 3 cords of spruce & will be using it. & some 2 yr old birch mixed in with the 1 yr old stuff .
Not enough 2 yr old birch to finish off the winter but when it gets cold again, I can burn hotter & it is not an issue
(except I know it's not as efficient, & should be drier)

DRY WOOD is the NUMBER 1 KEY to good wood burning. I knew that & know it even more now.

Maybe it's the bark, maybe it's my seasoning technique or weather or what ever, but now I'll plan to
season it (birch) longer/better. Just not enough 2 yr birch, but I have enough spruce to get thru this yr.
But it follows my "It's The Wood Stupid" when having burning issues. Look at the wood 1st! for problems.

BURN DRY WOOD!

I'm still learning why :)
 
The CO is the biggest problem here - you should never have flue gases leaking back into the room - you need to find where they are coming from - joints, leaking stove, reverse flow down flue - can you explain your setup?
 
CarbonNeutral said:
The CO is the biggest problem here - you should never have flue gases leaking back into the room - you need to find where they are coming from - joints, leaking stove, reverse flow down flue - can you explain your setup?

I agree. That is very disturbing to hear. CO is nothing to mess around with. This is the first time I've actually heard a first-hand report of CO gas leaking into the home from a running stove. You need to check that out, something ain't right.
 
Just an opinion, maybe on low setting the vapor in your chimney is freezing creating your C02 problem.
 
bogydave said:
I just brought in some dry spruce, & it is 40+ out side & have had trouble
with the house getting too warm. (75°+).
I was thinking the lower btu wood spruce would burn cooler.
I was still getting the house too warm & decided to turn the T-stat down &
watch it. It went into what I call the "smolder mode" (1) but kept a good glow of
hot coals. No smell or draft issues, all day (so far)


I think you have confused two issues, BTU's and burning temperature. My experience is the spruce will burn hotter and faster. What you have done is thought that there is a direct tie with btu and burn temp, not so. A higher burn rate will bring in more heat, but will also stop the smolder creating the CO.
 
CO is constantly being generated, even inside a well-functioning EPA stove. It's one of the emissions that are tested for in determining combustion efficiency. The concern is how is it getting out of the closed firebox and into the room, particularly at levels that are high enough to set off the CO detector? Maybe the detector is defective? Otherwise, I think it is an unsafe condition. My two cents.
 
CO2 detectors have a limited lifespan of 3-5 years after which they will false constantly. My suggestion is, first check and see if there is any way that flu gasses can be escaping the stove and entering the living space. If so, seal up ASAP. If the device keeps sounding an alarm, buy a new one and see if it does the same thing. My gut feeling is that you have a bad CO2 detector on your hands, but that has yet to be proven.
 
Yeah, I hated to do it, but I tossed my old CO detector when it started giving false alarms.
 
richg said:
CO2 detectors have a limited lifespan of 3-5 years after which they will false constantly. My suggestion is, first check and see if there is any way that flu gasses can be escaping the stove and entering the living space. If so, seal up ASAP. If the device keeps sounding an alarm, buy a new one and see if it does the same thing. My gut feeling is that you have a bad CO2 detector on your hands, but that has yet to be proven.

Very true . . . well sort of . . . 3-7 year life span depending on the manufacturer . . . and this is on CO detectors . . . haven't seen too many CO2 detectors in my professional travels. ;)
 
It sounds to me that you are burning too low to sustian adequate draft. There needs to be enough heat and volume sent up the flue to maintain the draft. Not enough heat and/or volume and it can cool too much before it reaches the top of the flue.
 
.

If you think they (CO2 alarms) aren't working properly, get new ones, but "have them" & "test them". IMO
Family Safety is #1
 
LLigetfa said:
It sounds to me that you are burning too low to sustian adequate draft. There needs to be enough heat and volume sent up the flue to maintain the draft. Not enough heat and/or volume and it can cool too much before it reaches the top of the flue.

That's what I found the problem to be.
20' stack, burning on low with "not real dry wood", fire almost goes out. Stack temp to low to keep a draft going. Reverse flow.
I get fumes from the single wall 8" black pipe at the stove & the joints.
I don't notice any leaking from the stove, but I never got down & looked/sniffed at the "inlet air" port at the bottom back of the stove.
Planning to replace the 90° "L" & put in 2 - 45° end of season. Was told this may help.

Plan to only use small amounts of real dry wood when above 40°f outside & not burn on "low" T-stat setting.
Or no fire
Or have a good fire & open some windows to keep the house cool (below 75)

I will never get rid of fire alarm or CO2 detectors. Maybe buy new ones, but seems prudent to have them if I have a wood stove running.
Burning wood, oil or coal & the heat system is in the house, seems to me to be a requirement. A must IMO.

If you think they (CO2 alarms) aren't working properly, get new ones, but "have them" & "test them". IMO
Family Safety is #1
 
richg said:
CO2 detectors have a limited lifespan of 3-5 years after which they will false constantly. My suggestion is, first check and see if there is any way that flu gasses can be escaping the stove and entering the living space. If so, seal up ASAP. If the device keeps sounding an alarm, buy a new one and see if it does the same thing. My gut feeling is that you have a bad CO2 detector on your hands, but that has yet to be proven.

May be I have the odd one but one of mine is a Kidde Digital from 1988. It still runs up the numbers and alarms when I take it out in the garage and fire up the snowmobile to test it. Yea I know I wouldn't bet my life on it exclusively but if it still works what the heck its just another layer in the safety net.
 
ps it's called the "CO" detector, not the "CO2" detector. just want to point out that distinction :)
 
Driz said:
May be I have the odd one but one of mine is a Kidde Digital from 1988. It still runs up the numbers and alarms when I take it out in the garage and fire up the snowmobile to test it. Yea I know I wouldn't bet my life on it exclusively but if it still works what the heck its just another layer in the safety net.


I'm not sure, but I think the new ones have exactly 7 years after you first plug it in before alarms sound indicating it needs replacement. That's what my electrician/plumber told me. Then again, he's an electrician slash plumber, not a licensed electrician. He may have made it up.
 
ruth140 said:
have you ever heard of the "Draw Collar" ? you might be a good candidate for it.
http://drawcollar.com/

Pretty cool product for marginal flues, but it uses electricity and it looks like the OP's problem can be solved by not trying to squeeze every last BTU out of his wood. Let 'er breathe, man. ;-)

I wonder what POOK would say about the Draw Collar? Maybe he'd try to put a Magic Heat right above it to reclaim the heat.:lol:
 
Battenkiller said:
Driz said:
May be I have the odd one but one of mine is a Kidde Digital from 1988. It still runs up the numbers and alarms when I take it out in the garage and fire up the snowmobile to test it. Yea I know I wouldn't bet my life on it exclusively but if it still works what the heck its just another layer in the safety net.


I'm not sure, but I think the new ones have exactly 7 years after you first plug it in before alarms sound indicating it needs replacement. That's what my electrician/plumber told me. Then again, he's an electrician slash plumber, not a licensed electrician. He may have made it up.

richg - 04 January 2011 01:58 PM
CO2 detectors have a limited lifespan of 3-5 years after which they will false constantly. My suggestion is, first check and see if there is any way that flu gasses can be escaping the stove and entering the living space. If so, seal up ASAP. If the device keeps sounding an alarm, buy a new one and see if it does the same thing. My gut feeling is that you have a bad CO2 detector on your hands, but that has yet to be proven.

Very true . . . well sort of . . . 3-7 year life span depending on the manufacturer . . . and this is on CO detectors . . . haven’t seen too many CO2 detectors in my professional travels.

-----------

As stated before . . . depends on the manufacturer as to when they should be replaced . . . 3-7 years was what we were told by the manufacturers when the inspector made some calls a year or so ago . . . then again . . . the inspector and I are not licensed electricians or plumbers . . . or CO manufacturers . . . just dumb firefighters. ;)
 
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