Strange Smell Issue; Carbon Dioxide?

helffric

Hi,

I've been dealing with an intermittent smell issue for some time. My Mother and I smell it; neither husbands, HVAC folks, nor the gas company smell it. Have a gas high efficiency boiler which heats water for baseboard heat as well as hot water. The smell becomes unbearable at night (usually around 11:30 or so on), it seems worst in front of the boiler when it occurs even when the burner is switched off via the emergency switch.

Worse than the smell, the symptoms include a bad taste in the mouth, scratchy throat, and upset stomach when it's at its worst. This all goes away during the day after airing out the house, even with the boiler running after closing up the windows, etc. The burner has been checked multiple times; no gas leak, no carbon monoxide (constantly monitored on all floors of the house).

Two questions:

1) Is it possible this could be due to an excess of carbon dioxide?

2) When I look into the burner itself, I see blue flames but also red hot 'sparkles' that don't seem to burn up. Is it possible there is some sort of foreign matter (insulation?) causing the problem inside the burner? The pictures are taken looking into the peep hole (which is about the size of a quarter). Is this normal?

I'm thinking perhaps while the burner is running, the smell is going out the exhaust which is piped out of the house, but as it sits unused, the remaining odor is escaping to the environment near the boiler and gets distributed over time around the house. (The air intake is open to the cellar).

Any help would be appreciated. Issue has been on going for months and professionals can't seem to find it.

Audrey

kcopp

Well CO has no odor. That being said something else is obviously going on.... A very simple fix for starters is to pipe the intake to the outside. Which make and model is the boiler?
You say that Co is constantly monitored...with what? Most of the "off the shelf" CO detectors cant sense low levels of CO.

The flame looks normal for a mesh style burner.
How old is the boiler?
LP gas or Natural?
How old is the house?
New baseboard has a odor to it when it is first run.
The other thought I have is...was the boiler set up w a combustion analyzer?

Jamie Hall

As kcopp says, CO (carbon monoxide) has no odour. Nor does CO2 (carbon dioxide). CO you don't want, but you won't smell it. CO2, in normal concentrations -- such as in your breath -- is harmless,.

Whatever you are smelling, they're not it. But it is possible that, if this is a new insulation, there is an odour from paint or finishes or sealants.

helffric

Which make and model is the boiler? Munchkin High Efficiency Boiler Modell number 199M
You say that Co is constantly monitored...with what?
The constant monitoring is done with off the shelf devices. However, multiple HVAC folks have checked the boiler and measured directly with their devices as well as the Gas Company personell (when the smell was at it's worse).

How old is the boiler? 8 years
LP gas or Natural? Natural
How old is the house? 60 years
New baseboard has a odor to it when it is first run. True, but odor started to occur before they had even been fired up for the season.
was the boiler set up w a combustion analyzer? I don't think so. It has a display which can display an impressive number of error codes, but they seem to be related to temperatures, fan faults, etc. However, here is the result of a combustion test done by the HVAC guy after firing it up and testing the exhaust by drilling a hole into the exhaust piping next to the boiler:

Combustion Test

Temp stack: 171.7 degrees Fahrenheit
7.3% oxygen
8 ppm CO
12 ppm CO Air Free
----- in H20 Draft
87.9% Eff gross
47.7% Excess air
7.62% CO2
---- ppm CO Ambient
71.6 degress Fahrenheit Ambient Temp

The odor was not around when doing this test. The boiler had been turned off at the emergency switch for about 24 hours (ie no heat or hot water). It had been running for perhaps 10 minutes when the test was done.

Thanks,
Audrey

vaporvac

This is the second post about this same topic. Hmmmm..... http://forum.heatinghelp.com/discussion/155899/steam-boiler-giving-off-acidy-taste#latest

helffric

Jamie,

We haven't been able to identify anything new in the environment such as paints etc when this started.

I read on the web (I know, always a dangerous thing
that with high concentrations of CO2, there are symptoms similar to what we are experiencing. I've ordered a CO2 detector just to rule this out. It's not the smell which is so disturbing, it's the effect on the throat, taste etc.

KCOPP,

I forgot to mention, I do have an appointment for the HVAC guys to install piping for the fresh air intake. Although the cellar is large enough by code to get air from the room, I figure it's better to do it this way, even if it doesn't get rid of the smell.

Even though the smell is strong around the boiler, I still don't know if this is a cause or an effect since when it is running, of course the fan is pulling in tons of air from the environment. However, since the smell occurs worst at night when we've had the boiler shut off at the emergency switch, I admit it's hard to imagine it's really from the boiler; but it's the only thing that we know has a flame (although it has no pilot light - spark plug instead) and the smell seems to be 'acrid'.

Audrey

Zman

Any chance the smell is coming from the floor drain?
If you pour some water in the trap you will eliminate the possibility....

Jamie Hall

Audrey -- I'll say it again: CO2 is naturally present. It's called carbon dioxide. You breath it out every time you take a breath. It is odourless, tasteless, etc. There are no detectors made for it for the simple reason it is there every time, all the time.

CO is a product of combustion. It's called carbon monoxide. The CO readings from your combustion test are also normal, but it would be harmful if it gets into your house. Indeed, it will kill you -- silently and effectively. I hope that it is a CO detector that you have ordered; any house with gas appliances in it should have at least one, anyway. CO is also odourless and tasteless.

If the smell is occurring when the boiler is off, it's not CO.

helffric

Hi Jamie,

Here is the website from which I ordered the carbon dioxide detector.

http://www.co2meter.com/

Yes, I agree we exhale CO2 and it's around everywhere. However, if the concentration is too high, it can make you feel sick. And even though it is considered odorless, so people have reported a pungent odor and a taste.

As I understand it, CO2 is the only gas your lungs recognize as a problem as you breathe too high a percentage. That's why CO is so dangerous; can't smell it and the lungs don't detect it as a problem. Supposedly, if you were in an environment that had no oxygen but was pure helium, as an example, you would not experience the feeling of not enough air before dying.

Anyway, I'm not saying it is CO2, I'm asking

Zman,

Funny you should mention the floor drain, I did go around and add water to the traps where we didn't use the water often (basement sink, etc), but I forgot the floor drain. I will do this immediately.

Thanks all,
Audrey

Jamie Hall

Well.. OK. A CO2 meter could be interesting. They are useful for some agricultural purposes... Your combustion test registers your CO2 in the stack exhaust as a bit below 8%. And you are correct -- at high concentrations it does have an acidic odour (as it dissolves in the moisture of the mouth and nose to form a weak acid).

A CO warning device would be recommended, just on general principles.

One thing is certain: if it is CO2 and the concentration is high enough to notice, you have really serious draught and ventilation issues, and I would say that CO2 is the least of your worries.

Quercus

Ozone created from electrical arcing creates a metallic taste. Are there any new devices with motors or fans with motors that could be malfunctioning? Or old devices...

helffric

I'm not aware of any new devices. I'm thinking of turning off half the breakers, see if the smell goes away, if not the other half, etc. to see if I can eliminate or verify this case. It takes at least a day to do each experiment as the smell is not constant. Worth trying I think.

Fred

Did they put any chemicals in this sytem when they installed/serviced it?

helffric

I don't know whether they did or not when they installed it 8 years ago; no chemicals were put in when serviced. Smell started about 2 months ago.

Fred

Are we sure nothing (like a squirrel ) crawled into the exhaust and made its way closer to the boiler and was "cooked" when the boiler fired up and continues to recook when the boiler fires? Is the exterior opening to the exhaust have a grate or some type of rodent proof cover on it?

ChrisJ

We can sit around and speculate all day.
The flue needs to be inspected and the draft checked.

Fred

ChrisJ said:

We can sit around and speculate all day.
The flue needs to be inspected and the draft checked.

Trouble shooting takes some questions. They have already said they have had service techs in, done a combustion analysis checked flue temps, etc. to no avail. all that's left is to continue to rule out other possibilites. Sorry if I am trying your patience, Chris.

ChrisJ

Fred said:

ChrisJ said:

We can sit around and speculate all day.
The flue needs to be inspected and the draft checked.

Trouble shooting takes some questions. They have already said they have had service techs in, done a combustion analysis checked flue temps, etc. to no avail. all that's left is to continue to rule out other possibilites. Sorry if I am trying your patience, Chris.

I must have missed that.
Though I have to assume this is a condensing boiler with these results?

Combustion Test

Temp stack: 171.7 degrees Fahrenheit
7.3% oxygen
8 ppm CO
12 ppm CO Air Free
----- in H20 Draft
87.9% Eff gross
47.7% Excess air
7.62% CO2
---- ppm CO Ambient
71.6 degress Fahrenheit Ambient Temp

Seems like the excess air is awfully high and the CO2 is awfully low for 87.9% efficiency?

Fred

It is a condensing boiler. I assumed it is direct vented, hence my question about something crawling into the exhaust.

ChrisJ

Fred said:

It is a condensing boiler. I assumed it is direct vented, hence my question about something crawling into the exhaust.

I'd expect that to trip a pressure sensor if it happened and no fumes should end up in the home.

The O2 and CO2 numbers still don't make sense to me, but I barely understand this stuff so I might not even be in the right ball park. I would've expected very high CO2 and very low O2 from a direct vent unit.

Fred

ChrisJ said:

Fred said:

It is a condensing boiler. I assumed it is direct vented, hence my question about something crawling into the exhaust.

I'd expect that to trip a pressure sensor if it happened and no fumes should end up in the home.

The O2 and CO2 numbers still don't make sense to me, but I barely understand this stuff so I might not even be in the right ball park. I would've expected very high CO2 and very low O2 from a direct vent unit.

Yea, I don't know this boiler or if it has any screening in the exhaust that would prevent a critter from getting into it and maybe dying on the top or side of the heat exchanger where it may not be an obstruction but could release an odor.

Aaron_in_Maine

Just food for thought. Have you had any work done on the house in general. I had a customer that had CO detectors going off in a three unit building. I was called in as a third party because the installer could not find the problem. New boiler only three months old. I asked if any other work had been done since the issue arose. "The roof was done but that shouldn't have anything to do with this. The boiler is vented out the side of the building." Well guess what was found in the attic a sewer vent that was not extended out through the new roof just sitting there in the attic. Sewer gases were setting off the co detectors. Problem solved

ChrisJ

Fred said:

ChrisJ said:

Fred said:

It is a condensing boiler. I assumed it is direct vented, hence my question about something crawling into the exhaust.

I'd expect that to trip a pressure sensor if it happened and no fumes should end up in the home.

The O2 and CO2 numbers still don't make sense to me, but I barely understand this stuff so I might not even be in the right ball park. I would've expected very high CO2 and very low O2 from a direct vent unit.

Yea, I don't know this boiler or if it has any screening in the exhaust that would prevent a critter from getting into it and maybe dying on the top or side of the heat exchanger where it may not be an obstruction but could release an odor.

The unit should have a pressure switch that would trip if that ever happened and they're fairly sensitive. Even if you tried to plug the vent and bypass the switch I'd expect zero leakage into the structure.

Jamie Hall

Aaron has a good point. The OP mentioned something about not having a problem until about two months ago. A good place to start a different search would be what was changed around that time? Just because it seems irrelevant is not important -- it could be anything. One of the first rules of troubleshooting: if something was changed, and then something happened you didn't like, check the change, however, silly it may seem.

helffric

Thanks all for comments, etc.

The exhaust pipe does have a screen on it.

I had a different HVAC guy come out to take a look at things. He said that because the plastic connectors inside the boiler box (on the top part, not near the flame) are yellowed as well as the outside of the exhaust pipe (not as much), he suspects that there are pollutants in the air that are getting pulled into the boiler.

The boiler is in the cellar which has a bilco door to the outside as well as a inside door and steps to the bilco. There were some paint thinner cans in there which I have removed. There was an odor there between the inside door and the bilco door on the steps where the cans were stored, but not obvious within the cellar itself. I also found some moth ball boxes in the cellar which had an odor which I also removed. Supposedly, all of these things have been down there without change for at least a year, but I wonder about this.

We still have the problem after taking these items out of the environment (there sitting outside in plastic bags far away from the house), but it doesn't smell/taste quite as bad at night; although it's a bit nebulous, as the strength of the symptoms change from day to day anyway. I do smell a bad odor right at the fresh air intake hole after the boiler has been running awhile.

I will be getting someone to put in the air intake pipe ASAP. The new HVAC guy mentioned that the boiler may not run at it's peak efficiency without intake air from the outdoors. At least this guy agrees it should be done. The last HVAC guy told me that since the cellar was large enough, it doesn't need to be done; even though the manual for the boiler says it should be....

Anyway, since we still have the smell intermittently (ie at night), I can't help wondering if damage has occurred in the boiler from the fumes.

Gordy

Fred said:

It is a condensing boiler. I assumed it is direct vented, hence my question about something crawling into the exhaust.

Hey that happend at my moms with her water heater. Squirrel down the two story chimney in the vent pipe to two feet of the water heater.......bad!

Gordy

How about a pic of the boiler, and associated piping, including the condensate drain setup. With hopefully a neutralizer assembly.

Yellowing of the venting pipe could be leaching chlorides.

Zman

I just reread the original post and am wondering if the two of you share an allergy to the same thing. My first guess would be mold.
You and your mother smell it and no one else does. That fits...
It is worse at night. The house is closed up..
It is worse near the boiler. Does the boiler or other appliance pull it's air from inside the house? If so all the air replacing that air could be pulled through a mold farm in an exterior wall and would be concentrated by the boiler.
I would test the air for mold.
Carl

nathun42

It would be more accurate to say CO2 has no odor to most humans. By definition it is a VOC (volatile organic compound) and according to research from Beijing a number of mammals, especially mice, can smell it in extremely low concentrations. According to the research, humans have the CO2 sensitive cells in their breathing passages, but the proteins that make them work are defective. Which means it is possible a gene variant could make it possible that you could be smelling CO2.

clammy

even though u had some hvac companies out to chk it out has anyone recently serviced and cleaned your unit ?Has any one checked the plastic trap assembly and your vent piping for signs of leakage ,as for the fresh air intake should have been done from the start and make sure proper distances are maintained away from exhaust .Just wondering peace and good luck clammy

jessica1665

helffric said:

Thanks all for comments, etc. The exhaust pipe does have a screen on it. I had a different HVAC guy come out to take a look at things. He said that because the plastic connectors inside the boiler box (on the top part, not near the flame) are yellowed as well as the outside of the exhaust pipe (not as much), he suspects that there are pollutants in the air that are getting pulled into the boiler. The boiler is in the cellar which has a bilco door to the outside as well as a inside door and steps to the bilco. There were some paint thinner cans in there which I have removed. There was an odor there between the inside door and the bilco door on the steps where the cans were stored, but not obvious within the cellar itself. I also found some moth ball boxes in the cellar which had an odor which I also removed. Supposedly, all of these things have been down there without change for at least a year, but I wonder about this. We still have the problem after taking these items out of the environment (there sitting outside in plastic bags far away from the house), but it doesn't smell/taste quite as bad at night; although it's a bit nebulous, as the strength of the symptoms change from day to day anyway. I do smell a bad odor right at the fresh air intake hole after the boiler has been running awhile. I will be getting someone to put in the air intake pipe ASAP. The new HVAC guy mentioned that the boiler may not run at it's peak efficiency without intake air from the outdoors. At least this guy agrees it should be done. The last HVAC guy told me that since the cellar was large enough, it doesn't need to be done; even though the manual for the boiler says it should be.... Anyway, since we still have the smell intermittently (ie at night), I can't help wondering if damage has occurred in the boiler from the fumes.

jessica1665

I see that this is an older post and im new on this site but i have the same issue in a round about way but i live in an apartment complex and this chemical smell smells a lot like mothballs. It also seems to be at its most potent at around 11 pm or later but it also comes and goes during the day time. It gets so bad that anything i eat or drink tastes a little off and i get bad headaches. The weird thing about it is that sometimes it will be really bad in the hallway and not inside my Apartments and vice versa and my neighbor across the hall will smell it in her apartment as well and it could be very potent in hers and not in mine. When the smell does get bad I have realized it does come from the pipes coming up into my place from the boiler so are insulated those and it also is coming from the electrical openings and light switch plates which I've insulated those now as well which has definitely brought the smell potency down but I can still smell it. If you come up with anything at all cuz I have gone through everything that I can think of to try to eliminate this problem and I have not been able to find anything or anybody that knows anything. I've called my landlord several times and they come here to inspect and can't find anything but obviously the smell is not good and it shouldn't be here cuz it was never here before. Anybody that has any kind of insight would greatly be appreciated

nicholas bonham-carter

Dead animals rotting, like mice under the floor boards, can have a persistent bad smell, although probably, not like mothballs. Usually this situation arises, when people use poison, instead of traps to exterminate them.
Could one of your neighbors be using a kerosene stove, or even cooking up some illegal concoction?—NBC

wmgeorge

helffric said:

Jamie,

We haven't been able to identify anything new in the environment such as paints etc when this started.

I read on the web (I know, always a dangerous thing
that with high concentrations of CO2, there are symptoms similar to what we are experiencing. I've ordered a CO2 detector just to rule this out. It's not the smell which is so disturbing, it's the effect on the throat, taste etc.

KCOPP,

I forgot to mention, I do have an appointment for the HVAC guys to install piping for the fresh air intake. Although the cellar is large enough by code to get air from the room, I figure it's better to do it this way, even if it doesn't get rid of the smell.

Even though the smell is strong around the boiler, I still don't know if this is a cause or an effect since when it is running, of course the fan is pulling in tons of air from the environment. However, since the smell occurs worst at night when we've had the boiler shut off at the emergency switch, I admit it's hard to imagine it's really from the boiler; but it's the only thing that we know has a flame (although it has no pilot light - spark plug instead) and the smell seems to be 'acrid'.

Audrey

Without reading further... sewer gas from a dry floor drain. Add some water, a small bucket full at least and check for other sources. Plus most folks here know this but the water leaving a condensing furnace is slightly acidic and will eat brass and copper.

neilc

any chance the apartment complex is in an industrial area, or business zone?
could the boiler be pulling a neighbor's stink into the complex?
and cleaners, kitchens, other, in the hood?

wmgeorge

neilc said:

any chance the apartment complex is in an industrial area, or business zone?
could the boiler be pulling a neighbor's stink into the complex?
and cleaners, kitchens, other, in the hood?

Or in the drain and the trap is not full of water... a dry trap. We used to get service calls all the time in the commercial HVAC/R world and that is what it was and some are stinky... bad