Here It Is - 4:00 AM and CO Detector Woke Me Up

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W

WNY PAT

Member
Oct 28, 2008
46
Western New York
Middle of the night post to break the boredom here. So, at about 2:00 AM the CO detector in my son's room activates. Pull the battery, reset it and figure it is a fluke because none of the other detectors in the house have activated. We have one in every bedroom, one in the hallway, and three downstairs. Ya I'm anal, for just this reason. Anyway, take the detector out of our bedroom and put it in his and take his and put it in our bedroom. About 90 minutes later, the other detector activates again in his room so off to Grandma and Grandpas house the wife and kids go. I stay here because I don't feel like waking my neighbor up yet - he is also the volunteer fireman who responds to these calls with the special CO equipment. Anyway, here is the deal:

-chimney prefessionally installed - high end triple wall stainless. Have probably put 50 or 60 cords of wood through it and never had a problem. Probably have had 6 or 7 good fires so far this year and no problems. The pro who installed it was just here in early October to clean and inspect it - all was perfect. Less than half a coffee can of creosote after buring 12 or 13 face cords last year so seems all is well there.

- the woodstove had coals from yesterday morning - roughly 24 hours old but enough going where I didn't have to use a super cedar to get it going again just now. A special added bonus this fine night - as I am loading a medium sized chunk of maple in the stove - I feel the unmistakable sharp pain of a sting in my right index finger. Get the flashlight and lo and behold - a yellow jacket friend had sought refuge on that piece of wood and had returned to hiding underneath. Best wishes to the yellow jacket - and closed the door.

-the furnace is turned off - not running at all.

-the hot water tank is power vented and I went down and put a detector next to the vent for 45 minutes and it didn't activate.

-our stove is gas - the pilot light is on and the oven and burners are off

-outside is dreary, heavy air with rain and maybe a few wet snow flakes

-our house is extremely tight and well insulated

Anyway, now that the family is gone, I have reset the detector and cracked the back door for awhile. I also started a fire because what I assume happened is a situation with the cold heavy outside air flowing down the chimney and forcing the CO from the remaining coals back out through the air intake. What do you guys think? Likely scenario? I'll post again when I wake the neighbor - as I said, for now all is quiet no alarms and back door is open. Get to catch up on some work until 7:00 when I'll call the neighbor.
 
I guess the way I would look at that , one CO meter Ok maybe, But 2 CO meters wrong no way. You did the right thing but let us know what is causing the problem.
 
I would think the same. Are you still with us?
 
Did you have chili for dinner? Methane? Just kiddin. CO is a scary thing. We (the ambulance service I work for) responded to a call for an "Ill patient" no alarms last year. The CO in the house almost knocked out 1 medic and 1 EMT. They became very sick for a few days. Still don't know how the homeowner was still alive since the amount effected the EMS crew almost instantly.

After the second alarm I might have got your neighbor so you could find the source. I hope everything turns out for the best.
 
Cold air backfeeding down the chimney would be my first guess.

I believe CO detectors work a little different from smoke detectors. A smoke detector will send out an alarm as soon as it detects smoke. A CO detector waits until a sizable amount of CO builds up in the detector than the alarm will sound. I think once a CO dectector alarms sounds you are supposed to take it outside to let it clean and air itself out. The fire guys should know more about this than I do?

Keep us posted please.

RPK
 
It might be helpful to know what the CO level was that tripped the detector. Was it a high level spike or a low level long term reading? A detector with a digital display would help. I need to get at least one of those myself. Please let us know what you find. It's interesting that only the one room tripped. Are there forced air heating ducts in the house?
 
Hey - yes still here - thanks for worrying. I don't have a digital CO monitor but am buying one today - same advice I got from the neighbor. No discernable CO in the house when he brought the equipment in - a complicated probe looking thing. We ran furnace, hot water tank and he checked all around the indoor stove pipe and door of the Fireview and no significant readings. I guess there is always some small amount in homes, but only at a certain level would there be any health risk posed. Anyway, he told me the detectors I have trip at 420 or 440 PPM (I think PPM - it was 420 or 440 though). He agreed that the likely cause was cold air flowing down chimney. I'm sure you guys know this but it was informative for me to hear him talk about chimneys and flues and such. He said basically the house acts like a chimney too and the up draft in the stove pipe (warmer side) has to overcome the down draft in the stainless pipe (colder side even though insulated) when there is no real fire going to move the warmer air up. With the cold, damp and heavy air and just some coals he thought it started drafting down the chimney, stoked the coals up with more air than could come through the air intake to push against it and once this downward flow of air was establised, it would remain that way until the pressure inside the house / heat in pipe increased enough to push the air back out and up the chimney and reestablish an upward draft - thus the fumes were pushed down and back in to the house.

So, other than the digital CO monitor, he also recommended that once the coals really die down, either get the fire going again or at least scoop most of the ashes and coals out if it is going to be idle for awhile. He also said as this type of chimney set up goes (thru-wall, T, triple wall stainless up on outside wall), it is very good and the draft is fine. OTOH, he said that it is only as good as it can be and it isn't ideal in terms of minimizing this sort of occurence. He said that really the ideal situation would be a chimney located inside the house but that unfortunately most aren't "designed in" that way. He's going to stop by after work for a thank you beer and take one more set of reading just to be safe. I'll let you know if anything changes - and he also said we can compare the digital monitor to his expensive set up to see how accurate it is. Thanks... any more thoughts or insights always appreciated!
 
fire_man said:
It might be helpful to know what the CO level was that tripped the detector. Was it a high level spike or a low level long term reading? A detector with a digital display would help. I need to get at least one of those myself. Please let us know what you find. It's interesting that only the one room tripped. Are there forced air heating ducts in the house?
Click to expand...

Tony, I'd advise you to go ahead and get one, it'll be worth ten times the cost just in increased peace of mind.

Since CO buildup in your blood is a concentration/time function, you can get a dose that will sicken you from long exposure to low levels or shorter exposure to higher levels. The detectors without the digital displays don't give you that info. They won't sound the alarm for as long as an hour at 70 PPM, or as short as 4 minutes at 400 PPM. Sure is nice to be able to tell the difference.

I have had mine show a peak of 20 PPM just minutes after forgetting an open bucket of ashes when I ran for the phone. Another time, I forgot to close the top loading door and was working on a hefty bed of coals with the front doors opened. I was sitting down in front of the stove and didn't notice anything (no smoke from the coals) until I tossed a couple small split on and they started to burn. With both the top and front doors opened, the draft was effectively killed. Smoke came drifting out of the top load door. I shut it and finished my work. Maybe 5 minutes elapsed all told, but the detector was sensitive enough to pick up a 25 PPM concentration all the way up in the bathroom at the top of the basement stairs.

This is the unit I got:

Kidde Plug-In Digital CO Alarm with 9 Volt Backup $40 at HD.

It will detect a transient CO level as low as 15 PPM. That's way below a level of toxicity for any exposure time, but high enough that you should at least find out where it's coming from. $40 at HD.

I know some folks aren't concerned with CO since they believe it will never be a problem and they have never experienced symptoms. Everybody feels that way until it's too late. It's poison, and like any poison... don't take any of it.
 
If the house is very tight, I am wondering about air exchange. Did some additional sealing get done last spring/summer? Is there a whole house air exchange system installed? If not, I would at least have a window cracked open, just a little, near the stove and see if that stops the issue. If so, it seems like an OAK for the stove would be warranted if there isn't one already installed.
 
Battenkiller said:
fire_man said:
It might be helpful to know what the CO level was that tripped the detector. Was it a high level spike or a low level long term reading? A detector with a digital display would help. I need to get at least one of those myself. Please let us know what you find. It's interesting that only the one room tripped. Are there forced air heating ducts in the house?
Click to expand...

Tony, I'd advise you to go ahead and get one, it'll be worth ten times the cost just in increased peace of mind.

Since CO buildup in your blood is a concentration/time function, you can get a dose that will sicken you from long exposure to low levels or shorter exposure to higher levels. The detectors without the digital displays don't give you that info. They won't sound the alarm for as long as an hour at 70 PPM, or as short as 4 minutes at 400 PPM. Sure is nice to be able to tell the difference.

I have had mine show a peak of 20 PPM just minutes after forgetting an open bucket of ashes when I ran for the phone. Another time, I forgot to close the top loading door and was working on a hefty bed of coals with the front doors opened. I was sitting down in front of the stove and didn't notice anything (no smoke from the coals) until I tossed a couple small split on and they started to burn. With both the top and front doors opened, the draft was effectively killed. Smoke came drifting out of the top load door. I shut it and finished my work. Maybe 5 minutes elapsed all told, but the detector was sensitive enough to pick up a 25 PPM concentration all the way up in the bathroom at the top of the basement stairs.

This is the unit I got:

Kidde Plug-In Digital CO Alarm with 9 Volt Backup $40 at HD.

It will detect a transient CO level as low as 15 PPM. That's way below a level of toxicity for any exposure time, but high enough that you should at least find out where it's coming from. $40 at HD.

I know some folks aren't concerned with CO since they believe it will never be a problem and they have never experienced symptoms. Everybody feels that way until it's too late. It's poison, and like any poison... don't take any of it.
Click to expand...

Good advice. I think I'm going to swing by Home Depot today and pick one up. So you have yours plugged in on the 2nd floor? I was thinking of using mine in the same room I have my insert.

-Andre
 
havermeyer said:
So you have yours plugged in on the 2nd floor? I was thinking of using mine in the same room I have my insert.
Click to expand...

Stove is in the basement, hot air rises up the stairs and through a grate I installed in the bottom of the door. The bathroom is right at the top of the stairs, next to our bedroom. I want it where I'm breathing, not where the stove is breathing. Plus, since the polluted air would be rising up the stairs, it's likely that there would be more up here than in the basement anyway.

I believe code here requires there to be one CO detector on each sleeping floor. I'm going to get another for the basement next time they go on sale, not so much for the stove but for explosive gases as well. I use both acetylene and propane in my basement workshop, so I will be getting a unit that detects both CO and explosive gases.
 
Fake coal burner said:
This one if you burn natural or propane gas combo co. plug in 9 volt battery back up. with memory .
http://www.homedepot.com/h_d1/N-5yc1vZ1xi4/R-100003545/h_d2/ProductDisplay?langId=-
Click to expand...

Yep, that's the one I'm getting.

I had an incident that I described last year where my propane line got a hole blown in it from an electrical short right next to the copper pipe. All I saw was flame coming from the basement ceiling, so I grabbed an extinguisher and put it out. The breaker had tripped, so I decided to call the FD. They were pretty confused until they could start to smell the propane gas that was slowly filling up my basement from the open hole in the pipe. Apparently, when the morons who installed the gas line drilled through the sill, they nicked an electrical cable and fed the pipe right through the hole and next to the cable. It sat there like a ticking time bomb for 13 years until something (maybe a mouse) moved them into contact. If the FD hadn't been there and I just went to sleep after putting out the fire without detecting the leak, I wouldn't be typing this right now. The propane line was about 10' from my running wood stove. :bug:
 
Glad everything turned out OK! Like Battenkiller said, the scary thing about CO is that it's cumulative and takes a long time to clear from your system.

We usually associate suffocation with CO2. CO2 replaces the oxygen in your lungs, preventing you from getting enough oxygen in your blood, but as soon as you remove the CO2 from your air supply, your body starts picking up all the oxygen it needs and your blood immediately becomes oxygen rich. Recovery is quick, as long as there was no brain or organ damage.

CO, on the other hand, doesn't have to replace the oxygen in the air you breathe to be a problem. Instead, it's actually absorbed into your blood and bonds to your hemoglobin with a greater affinity than oxygen itself! Because the CO-hemoglobin bond is stronger and more stable than the oxygen-hemoglobin bond, it can take days to clear the CO from your system. Essentially, you suffocate long-term due to a decreased ability for your blood to carry oxygen, even after you move to an area without any CO and a high oxygen content.

A person suffering from CO poisoning will look rosy-cheeked and healthy because the CO turns the hemoglobin bright red. Like altitude-induced hypoxia, CO-induced hypoxia can also lead to euphoria and poor judgement, so people often lose the ability to recognize the signs and symptoms in themselves and in other around them. I've seen a lot of aviation related deaths from both altitude and CO hypoxia where the pilots were happy as clams and talking to ATC while they slowly became incapacitated and died, even with ATC and other pilots begging them to descend or vent fresh air into the cockpit (depending on the suspected cause).

Because of the cumulative, long-term bonds created in your blood and the proven inability to recognize symptoms in yourself, I wouldn't recommend staying in an area with a suspected high concentration of CO. By the time you feel light-headed, you're already quite a ways down the back side of the hill and climbing back to the top can be quite an ordeal.

***Edited to bold the really important part***
 
Hmmm . . . you've burned 50-60 cords and never had a problem until now . . . I suppose the idea of the cold air coming down the chimney is possible . . . but very unusual . . . normally just the heat given off the coals and coming from the air in the house is enough to maintain the draft . . .

My only bit of advice . . . if it happens again call the FD right then and there . . . volunteer or career it doesn't matter . . . we all signed up for the job and we are there to respond to any emergency regardless of the time of day (or night) . . . by calling right away and not venting the place the FD can respond and attempt to more accurately pinpoint the source of the CO right then and there vs. coming in after the place has been vented and trying to figure out what could have set off the CO detectors.
 
Stupid question - is this a metal oxide detector? If your house is particularly humid, and you mentioned it was a tight house, the new-and-cheap or old detectors which use metal oxide literally will rust to death.

If you have high humidity (steamer?) and all metal oxide detectors of roughly the same age, it's entirely possible they all are pretty much shot and putting them into the humid room was just enough to push it over.

How old is it? What sensor is there?
 
Fake coal burner said:
This one if you burn natural or propane gas combo co. plug in 9 volt battery back up. with memory .
http://www.homedepot.com/h_d1/N-5yc1vZ1xi4/R-100003545/h_d2/ProductDisplay?langId=-
Click to expand...


I want to get it, just for this review:

"I would recommend this detector to anyone that wants to keep their family safe. It has gone off a couple of times when my wife burnt some food on the stove. It even surprisingly went off once when the family cat passed gas right under where it was plugged in. That was not expected, but shows how good it is at detecting gas leaks."
 
I'd also consider doing any extra sealing of the ceiling (poet and I didn't know it!) you can to reduce the whole-house-chimney effect. It may be hard to do (bathroom moisture fan, not much you can do about that although there are hoods on the roof vent that close under gravity) but there may be things here or there that you can caulk from the attic or ceiling. Attic access hatch, etc.

An extra section of chimney pipe may very well provide peace of mind if you're reasonably certain it's the woodstove causing the CO exposure, too.
 
So I purchased 3 of the Kiddie Nighthawk DC/AC units from Home Depot and plugged them in about an hour ago. One about 8 feet from wood stove (in our main great room), another in the room that the detectors activated in last night and one in my other son's room. Feeling a sense of relief as all continue to read zero. I have a small fire going and have run the furnace for the past 45 minutes or so as well as kicking the hot water tank on. Scary situation - and glad I have the CO detectors all over the house. Now I have 10 - with one set up next to the furnace and HWT. The detectors are only a couple years old - all battery operated Kiddie brand. As for the coals - I was surprised there were any left at all - my guess is the cold air draft stoked them up quite a bit. Another reminder of why it is so important to go the extra mile for safety and use proper ash buckets and non-combustable storage containers even when it seems like overkill. I would seriously have thought no real coals left.

Anyway, many thanks again for the ideas and the help. I'm going to be running this stuff down. If my neighbor finds anything of note, I'll keep folks updated. :)
 
estang said:
I guess the way I would look at that , one CO meter Ok maybe, But 2 CO meters wrong no way. You did the right thing but let us know what is causing the problem.
Click to expand...

I always have several (or more) working CO detectors around. You can't rely entirely on any warning device. If a single smoke detector is activated, you should smell smoke, right? CO is different. You can't smell it, so one detector warning you of a problem may leave you thinking "maybe it is defective", but two or more should leave no question that a real problem exists.
 
Battenkiller said:
fire_man said:
It might be helpful to know what the CO level was that tripped the detector. Was it a high level spike or a low level long term reading? A detector with a digital display would help. I need to get at least one of those myself. Please let us know what you find. It's interesting that only the one room tripped. Are there forced air heating ducts in the house?
Click to expand...

Tony, I'd advise you to go ahead and get one, it'll be worth ten times the cost just in increased peace of mind.

Since CO buildup in your blood is a concentration/time function, you can get a dose that will sicken you from long exposure to low levels or shorter exposure to higher levels. The detectors without the digital displays don't give you that info. They won't sound the alarm for as long as an hour at 70 PPM, or as short as 4 minutes at 400 PPM. Sure is nice to be able to tell the difference.

I have had mine show a peak of 20 PPM just minutes after forgetting an open bucket of ashes when I ran for the phone. Another time, I forgot to close the top loading door and was working on a hefty bed of coals with the front doors opened. I was sitting down in front of the stove and didn't notice anything (no smoke from the coals) until I tossed a couple small split on and they started to burn. With both the top and front doors opened, the draft was effectively killed. Smoke came drifting out of the top load door. I shut it and finished my work. Maybe 5 minutes elapsed all told, but the detector was sensitive enough to pick up a 25 PPM concentration all the way up in the bathroom at the top of the basement stairs.

This is the unit I got:

Kidde Plug-In Digital CO Alarm with 9 Volt Backup $40 at HD.

It will detect a transient CO level as low as 15 PPM. That's way below a level of toxicity for any exposure time, but high enough that you should at least find out where it's coming from. $40 at HD.

I know some folks aren't concerned with CO since they believe it will never be a problem and they have never experienced symptoms. Everybody feels that way until it's too late. It's poison, and like any poison... don't take any of it.
Click to expand...

Battenkiller:

Thanks for the tip for the Kiddie. I've been looking at that one already. I think it's worth the piece of mind to have the digital display, at least for one or two units in the house.
 
For what it is worth, I had two of them "go off" in two separate houses, miles apart.

It seems these things are programmed to die at 7 years from the time you stick a battery in them. I had installed them both within a day of each other. Here is what Kidde says about it:

https://portalgb.knowledgebase.net/display/4/kb/article.aspx?aid=293156&n=1&docid=2574675&tab=search

How to Determine if Your Alarm is at the End of its Life

* Seven years after initial power, a Kidde CO alarm will begin "chirping" every 30 seconds.The chirp will not stop until the unit is powered off.If the alarm has a Digital Display, it will show "ERR." When the unit shows "ERR," press and hold the Peak Level Memory Button. This will cause the digital display to show "E," "O," and "9." This is the "End-of-Life Warning," and the unit needs to be replaced.
* You'll know that this is an end-of-life warning, and not a low battery warning because replacing the batteries will not stop the chirp.The chirp will stop only when the alarm is powered off. Note: the alarm will not detect the presence of CO when in this mode.Replace the CO alarm with a new one immediately.


Why Alarm Replacement is Necessary



* UL 2034, the independent standard applicable to CO alarms, requires CO alarms to have an end of life warning.This requirement went into effect in March 2007, meaning any CO alarm manufactured after April 2007 with a UL listing must have this feature. Most states that require CO alarms in residential dwellings mandate that the alarm meet the UL 2034 standard.
* CO alarms are measuring instruments that monitor your home 24 hours a day, seven days a week.They are designed to provide accurate readings of this odorless, invisible and tasteless gas, which are shown in parts per million (ppm), throughout the life of the alarm.However, like most home appliances or instruments, they don't last forever. In addition, unlike the instruments used by home maintenance and fire professionals, residential CO alarms cannot be calibrated periodically to verify accuracy.For this reason a residential CO alarm must have a defined end of life.
* Sensing technology in CO alarms has made several advances since these devices became common in households.In order to benefit from the latest innovations, Kidde recommends consumers replace their CO alarms every seven years.
* All Kidde CO alarms manufactured after 2001 contain an end of life warning. This warning is set to sound seven years after the unit received initial power.Kidde conducts long-term reliability tests, which show that our CO sensors perform consistently for at least seven years.In addition, beginning in 2008, Kidde increased its warranty on the Nighthawk CO alarms from five to seven years.

For more information about your specific alarm, please refer to your user's manual found in our Download Center.
 
With my Hydro Heater, i've often had this problem. Outside 3 story chimney, and when the fire's dying out, there's a backflow of cold air down the chimney. It's usually not a high rating, but still, whenever a CO detector goes off, it makes you worry.

There is a HUGE DIFFERENCE in CO detectors. Some are extremely sensitive, others not so.
 
Glad to know everyone is OK. Sounds like you narrowed down the cause to the stove. The only thing I would add - you mentioned 'heavy wet air', but humid air is actually lighter than dry air. Many people will note it is a little harder to maintain a good draft on rainy days because of this. But this also supports your theory of a downdraft in the stove.

If the air is truly 'heavy' - say on a cold, very dry day - that is when you will get the best draft.
 
Interesting! Although it was one of those nights with NE winds and snow / fog / drizzle - so it FELT heavier. I swear! :)
 
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