CO alarm going off. MAKE SURE YOU HAVE ONE

Wearb

Was called to a neighbours house last night because they had a persistent CO alarm. There was no obvious combustion taking place anywhere in the house. The had a log pile in the rarely used open fireplace. I asked if they thought there might be smouldering ash under them and they said no (not used since Christmas), but they had installed a chimney balloon 2 days ago. While investigating the logpile, I noticed a little heat from the back boiler. They said that it had always been that way when the oil heating was on. I removed the logpile (some of the logs were warm) and closed the window and doors. Brought back the CO alarm from the kitchen and left it there with room closed up in normal fashion for nearly an hour and no problem. (We were careful to mind ourselves mind the kitchen/dining room)
I didn't have my analyser, but then brought the CO alarm out the removed logs in the shed and lo and behold, off it went again.

I just post this as a cautionary tale. It is hard to be careful enough and foresee everything.

Dtp1979

Wearb wrote: »

Was called to a neighbours house last night because they had a persistent CO alarm. There was no obvious combustion taking place anywhere in the house. The had a log pile in the rarely used open fireplace. I asked if they thought there might be smouldering ash under them and they said no (not used since Christmas), but they had installed a chimney balloon 2 days ago. While investigating the logpile, I noticed a little heat from the back boiler. They said that it had always been that way when the oil heating was on. I removed the logpile (some of the logs were warm) and closed the window and doors. Brought back the CO alarm from the kitchen and left it there with room closed up in normal fashion for nearly an hour and no problem. (We were careful to mind ourselves mind the kitchen/dining room)
I didn't have my analyser, but then brought the CO alarm out the removed logs in the shed and lo and behold, off it went again.

I just post this as a cautionary tale. It is hard to be careful enough and foresee everything.

You should do a co room test with your analyser wearb. It'd be interesting to see how many ppm is being produced

Wearb

Dtp1979 wrote: »

You should do a co room test with your analyser wearb. It'd be interesting to see how many ppm is being produced

Just got it back today after new cell and calibration. Not much point in doing test now with logs removed. I would have really liked to have had it at the time. Isn't that just typical that the only time I was ever asked to check out something like this, my analyser was away.
If I had had it, he might have offered me a few bob instead of coffee and digestives

jimf

Wearb wrote: »

Just got it back today after new cell and calibration. Not much point in doing test now with logs removed. I would have really liked to have had it at the time. Isn't that just typical that the only time I was ever asked to check out something like this, my analyser was away.
If I had had it, he might have offered me a few bob instead of coffee and digestives

wer they even chocolate digestives

scudo2

Very strange.
You only get co from something burning. Logs won't burn from hot water in back boiler IMHO
The balloon has me suspicious as to ask if the fireplace backs onto a neighbours fire ?
Chimney leaking across maybe ?

Puzzle is. Do warm logs absorbes co ??

sawdoubters

balloon blocks chimney

remove ballon problem solved

Dtp1979

scudo2 wrote: »

Very strange.
You only get co from something burning. Logs won't burn from hot water in back boiler IMHO
The balloon has me suspicious as to ask if the fireplace backs onto a neighbours fire ?
Chimney leaking across maybe ?

Puzzle is. Do warm logs absorbes co ??

Stored Wood pellets give off CO so maybe warm logs too. Wearb get a hold of those logs and do a few experiments at home!!

scudo2

Dtp1979 wrote: »

Stored Wood pellets give off CO so maybe warm logs too. Wearb get a hold of those logs and do a few experiments at home!!

A few well aired solid logs ?
Sets off alarm that is a distance away!

I'd suspect cracked chimney.

Remove logs and leave co alarm in the grate while neighbours light fire, leave balloon in place but be safety conscious while doing test. Or test with FGA



If it was the logs then I'll never walk in the woods on a hot day again.

Dtp1979

The only sure way is to do a few tests. A room test using the analyser with and without the logs.

Wearb

Funny you should say that DTP. Just back from there. I was worried in case I missed something. I did a room test with analyser set for flueless space heater and there is no CO.
I cant ask them to put logs back in to fireplace to experiment with them.

Scudo! As already said, wood pellets have been known to give off CO without even the presence of heat.

Jim! no they were ordinary digestives, so not even doing well there

sawdoubters! Doh!

anuprising

rookie mistake

all CO alarms are prone to false positives or cross sensitivity ,from hydrogen but the number one culprit is humidity . your neighbours installed a chimney balloon 2 days previous immediately affecting the humidity in the room , this happens as the temperature rises , like when the heating is on (back boiler) and can have different readings at different areas of the same room depending on the temperature and humidity in a given spot .

every analyser is also prone to false positive , humidity can set off gas detection on them also

lynski

anuprising wrote: »

rookie mistake

all CO alarms are prone to false positives or cross sensitivity ,from hydrogen but the number one culprit is humidity . your neighbours installed a chimney balloon 2 days previous immediately affecting the humidity in the room , this happens as the temperature rises , like when the heating is on (back boiler) and can have different readings at different areas of the same room depending on the temperature and humidity in a given spot .

every analyser is also prone to false positive , humidity can set off gas detection on them also

totall ot but saw this and was curious - can it do that to a wire
d smoke detector in a house? ours goes off seemingly randomly, with the front door wide open yesterday and it is 2 meters from it. ?

anuprising

lynski wrote: »

totall ot but saw this and was curious - can it do that to a wire
d smoke detector in a house? ours goes off seemingly randomly, with the front door wide open yesterday and it is 2 meters from it. ?

humidity also causes false positives in smoke alarms but im not familiar with them, only CO and gas detection

Wearb

anuprising wrote: »

humidity also causes false positives in smoke alarms but im not familiar with them, only CO and gas detection

So how do you recognise a false positive? You can not sssume false alarm. Action has to be taken. How do you explain alarm not going off since logs removed?

I would like to understand this if you wouldn't mind explaining it please.

anuprising

http://www.ehow.com/info_8365144_can-false-carbon-monoxide-alarm.html

google brings up loads ,

Wearb

anuprising wrote: »

http://www.ehow.com/info_8365144_can-false-carbon-monoxide-alarm.html

google brings up loads ,

Thanks for that. I have been reading a bit and I am not fully convinced that I had a false alarm at neighbours. Same conditions (-logs) prevailed there last night and no alarm. Heating was on for same amount of time, same two people, balloon in place, co alarm in same position, doors and windows closed.
Hard to figure it out.

I had just brought back the FGA that I had borrowed a few hours before I was called. I was without an FGA for only a few hours the whole year and it had to happen during that period.

anuprising

don't know weather you went to any of the bord gais / rgi/ ei electronics information nights but the best advice given that night was to check with customers what has changed recently in the house . in your case it was a chimney balloon .
logs that are not burning dont give off CO - they can store Co2 but have to burn the o2 to produce CO -
no combustion took place so Logic and deduction tells me it was a false positive from either Co2 or humidity

Wearb

anuprising wrote: »

don't know weather you went to any of the bord gais / rgi/ ei electronics information nights but the best advice given that night was to check with customers what has changed recently in the house . in your case it was a chimney balloon .
logs that are not burning dont give off CO - they can store Co2 but have to burn the o2 to produce CO -
no combustion took place so Logic and deduction tells me it was a false positive from either Co2 or humidity

Thanks for bearing with me on this one.

If I accept that logs in that state doesn't give off CO, how do I square that with wood pellets in a colder state giving off CO?

Dtp1979

Wearb wrote: »

Thanks for bearing with me on this one.

If I accept that logs in that state doesn't give off CO, how do I square that with wood pellets in a colder state giving off CO?

Can you get a hold of those very logs?

Wearb

Dtp1979 wrote: »

Can you get a hold of those very logs?

I expect they are still where I left them and if so I would have no trouble getting them. Do you have some ideas?

Dtp1979

Wearb wrote: »

I expect they are still where I left them and if so I would have no trouble getting them. Do you have some ideas?

Maybe bring them home, leave them in a small room against a hot rad and turn on yer analyser to co room test after a while

Wearb

Dtp1979 wrote: »

Maybe bring them home, leave them in a small room against a hot rad and turn on yer analyser to co room test after a while

I did think of doing that. It would be difficult to recreate the same confined conditions as existed in the fireplace with chimney balloon. They would have to almost boxed in at the top and sides to trap the heat around them. I will give it some more thought.

Dtp1979

Wearb wrote: »

I did think of doing that. It would be difficult to recreate the same confined conditions as existed in the fireplace with chimney balloon. They would have to almost boxed in at the top and sides to trap the heat around them. I will give it some more thought.[/quote
Is say if they're left for a few hours to heat up then do the test you should get some CO

anuprising

if you put the logs in a shed , did the shed have any paint /paint stripper , turpentine , white spirits , petrol lawn mower in it ? all these can give false positives .
a carbon monoxide detector has an electrochemical cell so is prone to picking up levels of vapour chemical that send the electro signal to sound the alarm
just a thought

Wearb

anuprising wrote: »

if you put the logs in a shed , did the shed have any paint /paint stripper , turpentine , white spirits , petrol lawn mower in it ? all these can give false positives .
a carbon monoxide detector has an electrochemical cell so is prone to picking up levels of vapour chemical that send the electro signal to sound the alarm
just a thought

I didn't check for those things, but there was a lot of stuff there. There was probably a lot of the stuff you mentioned, along with lots more logs. This shed is tidier than most of my rooms. He is like that and everything is shelved out and in its place. If he has any petrol, spirit, etc. , it will be most certainly sealed in its container.

A lot of people store logs in their shed/garage. This is the first time I have come across this sort of alarm and would be surprised if those storing conditions are to blame. However your question does give cause for other areas of investigation into this issue. I will call around on Saturday and have a good look around the shed and see how hot the back boiler does get. I may have been there after the room stat had turned off the oil boiler for a while and the back-boiler may get hotter than I observed at the time.

Wearb

I had been discussing this thread with my neighbours and as they were going out last night he suggested that I could try and recreate the scenario if I wanted to. I accepted and brought back in the same logs, checked the balloon was in place. I had a co monitor from my house also just to be sure. I watched a film and then ran a room test. Peak co after 30 minutes was 3 ppm.

I know that it wasn't a very scientific setup. Maybe the wood needed to be there for weeks with open flue. Maybe it needed fresh wood. Or maybe as has been already said here, it was just simply a false alarm.

Toughest part was when asked if the logs could be left in the fireplace. I had to hedge my bets and say that if it was in my house, I would get a second co alarm before putting the logs back. I also suggested getting the heating back boiler sorted sometime. That will not be an easy job and probably will not be done in the near future.

Amyway that's hopefully the end of co alarms there.

Meant to add FYI that at times the back boiler got almost as hot as radiator. Also house is a detached bungalow in the countryside.

DGOBS

The logs could well have caused it, same as DPT said, producing CO as the fatty acids biodegrade with the heat (this is what they believe is happening to wood pellets also, but all studies are not in yet)

I will pass this one onto EI electronics though, just even to get further info, they are always interested in that kind of stuff.

Wearb

DGOBS wrote: »

The logs could well have caused it, same as DPT said, producing CO as the fatty acids biodegrade with the heat (this is what they believe is happening to wood pellets also, but all studies are not in yet)

I will pass this one onto EI electronics though, just even to get further info, they are always interested in that kind of stuff.

Thanks. I look forward to it being discussed further. It seems also that heat is not necessary for the production of CO in confined spaces.

After reading a lot about it during the last week (great video produced by the Swedes), I have come to understand that with logs in confined spaces, that O2 depletion is the high risk factor and with pellets its high CO, in fact CO in the thousand ppm. Concentrations that can kill with one breath. Now there is a sobering thought.
The Swedes (I think, or some of the EU countries) have a huge research programme to try and understand the process. They believe that numerous deaths are caused every year by wood stored in confined spaces.

DGOBS

Yes, one study was on cargo vessels transporting wood pellets, they found over the test period levels rose to over 1% in air (.04% being fatal over 3 hours exposure)

Wearb

DGOBS wrote: »

Yes, one study was on cargo vessels transporting wood pellets, they found over the test period levels rose to over 1% in air (.04% being fatal over 3 hours exposure)

And in case anyone is interested, 1% = 10,000 ppm and we get (rightly) worried at anything nearing 100 ppm

shane0007

Wearb wrote: »

And in case anyone is interested, 1% = 10,000 ppm and we get (rightly) worried at anything nearing 100 ppm

Room evacuation is 10ppm

DGOBS

Above 30ppm is an evacuation limit
CO alarms must react at level max 53ppm
(Within a give period)
10ppm over a 8hr test in a room with appliance warrants appliance shutdown
People would be symptomatic at 100ppm

Wearb

shane0007 wrote: »

Room evacuation is 10ppm

Sorry, I can see that I didn't make my sentence clearer. i meant here on the P+H forum regarding heating appliances. Seeing that we are discussing co levels inside a house, I should have been more careful.

thanks for picking up on it.

DGOBS

10ppm is appliance shut down
30ppm is evacuation

shane0007

Wearb wrote: »

Sorry, I can see that I didn't make my sentence clearer. i meant here on the P+H forum regarding heating appliances. Seeing that we are discussing co levels inside a house, I should have been more careful.

thanks for picking up on it.

Wasn't having a go. I was just adding to your post.

Wearb

shane0007 wrote: »

Wasn't having a go. I was just adding to your post.

I know! That is why I replied with a thank-you.

scudo2

Jesus. I've come across lots of boiler huts with the loads of ( warm !! ) timber drying out in them also !!!!


Needless to say I pointed out the fire risk but haden't any idea about a co risk.

One was even in a basement of an old house with a few tons of logs. It had an old Unidare, Selectos burner, broken asbestos flue + oil leaking every where.
Luckily it was one that I cut the wires and walked away from. It wasn't a case of me overacting, as I pointed out the dangers 3 years previously and refused to service it then.

Money was not an issue but brain cells were, for the client, that is.


Thanks again Wearb