So, we had a slight scare this weekend. Our stove’s gas burners have been a little orange these past few weeks, but on Friday evening they were much more orange than blue.
A quick Google search shows that an orange flame could be very bad. This usually means incomplete gas combustion, which could mean carbon monoxide production and accumulation, which is BAD.
It turns out that our ultrasonic humidifier in the other room was the most likely cause. We’ve been using tap water, and so either it was the moisture or minerals in the air that caused the gas burner flame discoloration. We turned the humidifier off on Friday evening, as the warmer weather meant less heating and less dryness. On Saturday stove’s burner flames were back to burning with their normal full-blue colors.
This seems like as good a time as any to encourage you to test your CO alarms, or to buy CO alarms if you don’t already have any.
CO is an odorless, colorless, and tasteless highly toxic gas. It has the potential to harm and even kill you.
CO is more easily picked up by red blood cells than oxygen. Thus, high CO concentrations means more CO replacing oxygen in the blood. This blocks oxygen from getting into the body, which could lead to tissue damage and death.
Symptoms of CO poisoning include: headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. CO poisoning symptoms have been described as being flu-like, but without fever.
If you live in a home with gas heating or cooking appliances, then you definitely should have at least one CO monitor or alarm.
CO can be created by malfunctioning appliances, appliances that are in need of calibration, improper use of appliances, and a number of other ways.
There is a lot of information over at the CDC regarding CO and CO poisoning.
Links: CDC CO FAQs, Workplace Guidelines, Prevention Guidelines
- Understand how CO is created and how it accumulates.
- Know the symptoms of CO poisoning.
- Purchase and install at least one CO monitor or alarm in your home.
- Test your CO alarms as directed, and change batteries or replace as needed.
- Know what to do in case CO poisoning is suspected.
CO poisoning can lead to confusion so severe that you know you are unwell but are unable to open a window or head outdoors to fresh air. This is why CO alarms are incredibly important – because they give you a chance to escape before you are incapacitated.
What to Buy?
We have a CO monitor of indeterminate age in the hallway of our single-floor apartment, but I purchased two more over the weekend. One to keep in the kitchen, which is right near the furnace room, and one more for the bedroom.
Both are Kidde battery-powered models:
Kidde Carbon Monoxide Alarm ($18 via Amazon)
This is a basic model that sounds when it detects 70 ppm of CO for 60-240 mins, 150 ppm for 10-50 mins, or 400 ppm for 4-15 mins.
Kidde Digital Carbon Monoxide Alarm ($25 via Amazon)
This one operates similarly to the basic model, but also features a digital display that indicates the level of CO that the unit senses.
Kidde and First Alert both produce battery-powered, plug-in, and combination carbon monoxide alarms. If you choose to buy an alarm or monitor from another brand, ensure it’s UL-rated.
Where to Buy?
We purchased the basic Kidde alarm locally over the weekend and the digital Kidde alarm from Amazon. Walmart, Target, Home Depot, Lowes, other home improvement stores, and any other store that typically carries smoke alarms carry carbon monoxide alarms.
It is recommended that carbon monoxide alarms be replaced every 7 years, unless the documentation that came with your alarm says otherwise. Earlier models needed to be replaced every 2-5 years. You should be aware that CO sensors do have limited lifespans, and that just because an older model appears to be functioning perfectly doesn’t mean it is.
If you don’t have any CO alarms or monitors in your apartment or home, BUY ONE, or several for multi-floor homes, as soon as you can. If you have older alarms that should be replaced, replace them. If you have CO alarms but haven’t checked them recently, TEST THEM as soon as you can. Test your smoke alarms too while you’re at it.
Where to Find Information
I am not an authority on CO, CO prevention, or CO poisoning, and so the above is merely my opinion. Refer to the CDC or similar channels for proper advice, guidelines, and recommendations.
A friendly couple from our church didn’t wake up one morning a few years ago. Seems a broken connector in their furnace chimney was the culprit.
We have CO monitors near the bedrooms.
I’ve got CO alarm units (plug-in with battery backup) on both floors of our house. We have a two story house with the first floor furnace in the basement and the second floor furnace in the attic. I had to replace the first floor one last year (I think, maybe 2 years ago) about 5 years after it was installed because the internals failed.
In California it’s the law all residential homes/apts/condos are required to have CO2 detectors. It became the law over the last few years. Still hear of deaths caused by CO2 but not as common now. Last fall there was an instance of 2 people dying after a non licensed HVAC contractor worked on a system for a 2nd homeowner. They showed up one weekend in early Oct…..never left next time they were seen was by the local Fire Dept who responded on a welfare check.
It’s worth it to buy the 9V lithium backup batteries at the same time. They last much longer than the alkaline variant. Same suggestion for smoke alarms.
Shouldnt the CO2 alarms be lower to the ground vs smoke alarms? Doesnt CO2 pool at low spots? I was pretty sure CO2 falls.
CO (not CO2) is slightly lighter than air – but will diffuse quickly into air mixing with the Nitrogen and Oxygen that we breathe. I’m not sure what CO detector manufacturer’s recommend for placement – but one of mine is plugged into a wall outlet, 2 are combination smoke/CO detectors wired into ceiling boxes (with battery backup)
and one is a ceiling mounted battery operated combination detector.
They should be mounted where there’s normal air flow.
CO won’t necessarily pool to the ground. Everything I’ve read says it will mix freely with the air and will move where the air moves. You probably won’t want it too high up where you cannot reach it for testing, or right in corners where there might be reduced airflow.
Carbon Monoxide’s specific gravity is .95 (ish, I’m probably off a hundredth or so) while air’s specific gravity is the benchmark at 1.0. Which means that CO is lighter than air and will rapidly mix with and disperse thru air. This is why when you think you have a CO problem, opening opposing windows is an effective way to eliminate the danger temporarily.
The big takeaway I tell my customers is that there are three main organizations that give recommendations as to CO exposure. The EPA wants less than 9 ppm for 24 hour exposure. OSHA will let you be exposed to 50 ppm for up to 8 hours as long as you’re in an area with less than 9 for the rest of the day. The American Gas Association regulates gas burning appliances and recommends an appliance has less than 100 ppm Carbon Monoxide Air Free and anything 400 ppm Air Free is a dangerous appliance and not to be operated.
So, most CO detectors are there for acute issues, not everyday overexposure.
This is to detect Carbon monoxide, CO, not carbon dioxide, CO2. Complete and efficient burning creates water and CO2. Incomplete burning or the burning of some hydrocarbons will also create Carbon monoxide. CO. This is a colorless and poisonous gas. It is lighter than than CO2 & O2 and will not sink and accumulate near the floor like gasoline vapor or propane.
We have two in our house. The Kidde model with the display is mounted at eye level (per the instructions) and another combo Smoke Alarm / Carbon Monoxide model on the ceiling (per its instructions). Both came with 10 year lithium batteries.
Actually read the little booklet that comes with them as you will want them to work if you ever need them to.
The Kidde alarms say wall mounted or on a table less than 3 feet off the ground to prevent damage in case of a drop. Smoke alarms usually specify high on the wall or on ceiling.
On the other end of the spectrum there are CO monitors like the one from NEST that communicate with your cell phone. NEST was recently purchased by Google if my memory serves my correctly. Whole house electronics is not to far away! Just makes one wonder how our tools will integrate into this new electronic world…..
Paul in Leyden
Pushing the test button checks electronics but I do not think it tests for the sensor’s ability to register CO. I recall the manual for my detector advising to light a cigarette or piece of incense, letting the smoke waft near the sensor so as to confirm that the sensor is registering CO.
There are also CO detector spray testers available. Amazon has one for $16 and I imagine that would last a home owner many years.
Even though I have no gas operated appliances in the house, I have a few, including one in a detached garage. I have two woodstoves which can also be a source for CO, but far less likely to quietly dump CO into the interior air without the accompanying smell of burning wood. Still, with the work I do on cars/engines around the house, I still err on the side of caution. The one in the garage will go off most of the times I start an engine in the building, with the small engines being the worst offenders. The detectors have gone off with engines running outside of the building as well, such as my standby generator. Turning on the exhaust fan for the building clears the air and resets the alarms, but the warning is a good reminder to be careful.
Note that most detectors like these use a chemical reaction cell as the sensing element, and these have a limited lifespan. There is a timer circuit built into the detector that starts when power is applied to the unit and after seven years will trigger the detector to emit a warning beep similar to a low battery signal, but more distinct. This can’t be reset by new batteries, and the detector will need to be replaced. Even the expensive Nest Protect is similarly equipped. This is a safety feature, since the sensing cell becomes less sensitive over time and will eventually miss concentrations of CO that can be harmful or worse. Regardless of how much you spend on a consumer-level detector, it’s a throwaway device in less than a decade. Far more expensive industrial detectors use replaceable sensing elements.
Smoke detectors also tend to become less effective over time as the sensing elements age. Ionization types can actually become more sensitive as they age if the radioactive element in the sensor decays below a certain level. These rely on a chamber of ionized air with an electrical current flowing through it, when smoke enters the chamber it impedes this current flow and the circuitry is calibrated to sound an alarm. A weak cell is seen as an obscured chamber, and can set off the alarm when the slightest amount of obscuring agents in the air, such as dust, enter the chamber. People then pull the batteries out of such detectors to shut them up, and there ends up being no warning when things get real. Many if not all current generation smoke alarms using ionization chambers have a ten year timer that will sound a warning chirp when the detector “expires.” Some of these detectors come with a permanently affixed lithium battery that acts in a similar fashion, the battery life is good for about ten years (unless you have lots of false alarms) whereupon you toss the entire unit for a new one.
I’ve seen at least one manufacturer advertising how consumer CO alarms with a UL cert have high thresholds and time delays before an alarm will sound. I believe the thinking was false alarms would cause people to ignore them, however that also means they are silent even when there is a slight issue with your appliances that should be addressed. Of course the same manufacturer sells and “ultra low” CO alarm that will notify you immediately at something like 1/10 the levels of all the others. I’d love to have someone confirm or debunk this as these ultra low units are not cheap. Still, if there is truth to it, i would pay the extra $.
The time scale for the Kidde alarms I purchased are listed above. As a commenter stated, these types of alarms are meant to alert people to acute CO situations, such as appliance failure or unusual exposure.
CO levels above 30 but below alarm thresholds can still be dangerous. This is why I purchased the digital display Kidde as well, which shows “peak” measurements, including levels below alarm thresholds. The display is supposed to refresh itself every 15 seconds.
I also considered a Fluke CO meter to see how that works, but it’s pricey ($350+) and requires annual calibration as well as sensor replacement every 3 years with unspecified servicing fees.
Given some states’ mandates for CO alarms in every home, and federal agencies’ urgings for the same, there have been great strides made in consumer alarms, such as how they only have to be replaced every 7 years now.
Ultra-low CO alarms, such as CO Experts’, use scare tactics to sell. They might still be a good idea for those concerned about low CO concentrations.
There’s also the option of industrial personal CO sensors, which I suppose could also be used in the home, but these require more maintenance and calibration than products designed for home use.
Having been in the business – working with HVAC systems – we used Bacharach and Sensit test equipment – and had calibration gas cylinders on hand. Defective combustion equipment was not the only source of CO – but other sources like smoking underground electric feeders- with infiltration paths along electrical conduits were uncommon and usually detected/corrected by the utility. We did see a number of instances where homeowners or unlicensed contractors had improperly installed water heaters with horizontal or even downward facing flues resulting in high CO levels. Sometimes this came about because the homeowner had wanted a larger capacity (taller) water heater than could be accommodated in the space to allow for proper angling of the flue. We also replaced many hot air furnaces over the years that had developed cracks allowing combustion gases to mix with heating air. The local utility would often detect these situations using Draeger Tubes
Stuart, have you been able to find any info that confirms your suspicions about the link between your humidifier and the issue with the burners?
A few weeks ago, before we ran the new ultrasonic humidifier (a $50 Crane model), there were no issues.
After turning off the humidifier, at least during the day, the burner colors returned to normal.
If the issue was with the appliances, such as improper calibration or malfunction, then the issue wouldn’t have corrected itself.
If the issue was beyond our appliances, neighbors would have also reported coloration issues.
The link between our humidifier and modified burner colors is not scientifically proven, but it’s the most likely explanation.
I understand the observations, just trying to understand the underlying science behind it.
The air in the apartment wasn’t very humid, so it’s unlikely that added moisture in the air was the cause.
It’s more possible that minerals deposited in the air from the tap water is what caused the discoloration.
We didn’t see any fine white powder normally associated with using tap water with high mineral content, but that doesn’t mean it wasn’t there.