What is carbon monoxide?


Carbon monoxide is a colorless and odorless gas.It is produced by the process of incomplete combustion.It is often referred to by its chemical name CO.It is quite deadly and varying amounts of it can be found in the gases produced by your gas water heater and furnace or in other things you are burning in your home, like the fire in a fireplace.


In a well maintained properly drafting system, the carbon monoxide goes up the flue pipe (or chimney in the case of a fireplace or a few furnace or water heater installations) and typically exits on the roof the house.But things can go wrong with this process and part or all of the flue gases containing the CO can end up in your house.They can make you very sick or kill you.


Every house should be equipped with at least one good, functional CO detector to protect you and your family and pets.There are several different types and brands of CO detectors on the market.So itís a confusing scenario for the consumer.Iím not a big fan of the battery only units.Yes, theyíre cheaper, but Iíve found more issues with them than I have with the 115 volt plug-in models.There have been a lot of recalls on the battery-only models too, even with the more reliable brands.


The units we see at the retail stores are typically U.L. 2034 rated.The U.L. 2034 rating specifies a certain minimum level of sensitivity.Weíve learned a lot more about the effects of CO on the body since this early standard went into effect in 1998.The current consensus of opinion is that this standard is far too lax on the amount of CO concentration required to sound the audible alarm on these units.


All CO detectors will emit an audible alarm when a certain level of CO is detected.But in many models, the audible alarm is the only indication that the CO level is high.Some of the more expensive models also have a 3 digit display showing the number of parts per million of CO.I wouldnít own a unit that doesnít have the display, because the audible alarm doesnít sound until the CO level reaches a pretty high point, i.e. a level that isnít good for you to be breathing around the clock.If the unit doesnít have a display, you would have no way of knowing that there is that much CO, especially with units that merely meet but do not exceed U.L. 2034 standards.


Some of the 115 volt plug-in models have a 9 volt battery backup system, that allows the CO detector to continue to function if the power in your house goes out.This is a very good idea, because there are still a lot of ways for you to get CO poisoning when the electricity goes out.I could really tell you some hair-raising stories about that.


Iíve seen an abnormally high amount of problems with certain brands of CO detectors.And while Iím not able to list those brands here for obvious reasons, when I go into a house and see one of them, I always recommend that they be disposed of.There are two types of issues Iíve seen with CO detectors.


  1. They go off when there is no CO
  2. They donít go off when there is CO


Obviously number 2 is extremely dangerous.But number 1 can also be dangerous, because people sometimes tend to disregard the alarm when a real threat exists.So itís like the little boy who cried wolf, and the wolf finally showed up.


When you buy a CO detector, always read the documentation that came with it, especially the part regarding the lifespan of the CO sensor in the unit.I have yet to see a sensor that claims to be designed to last more than 10 years.


There are now units that provide much higher thanU.L. 2034 levels of protection.But they are much more expensive, like typically in the $150 price range.I have yet to see any of these being offered by the department store/hardware store businesses in our area.


This is a hot topic among people in my field at this time.Many of my colleagues are of the opinion that youíre better off having NO CO detector at all vs. having one that only meets U.L. 2034 standards.While some of us feel that the $150 price tag of the better ones puts them out of the reach of many people.I can see both sides of this very complex argument.But thereís little disagreement on one point, i.e. that the U.L. 2034 standards simply arenít tough enough to protect you adequately.Nobodyís arguing that point.In my opinion, the solution is for the better models to come down to an affordable price and have the U.L. 2034 standard become upgraded to that higher level of sensitivity.


A lot of this has to do with educating people about the shortcomings of the current U.L. 2034 standard, which allows you to be exposed to harmful levels of CO for too long of a period of time before sounding the audible alarm.Thereís a lot more to it than Iíve laid out here.


For more information on this, go to the CO Experts website.


Freak CO incidents


Murphy is often at his best when it comes to CO.So a little common sense goes a long way.I read an article in the news a while back about a man who was found dead in his car off the side of the road of CO poisoning.An examination of the car and the scene revealed that the source of the CO was not from the car exhaust, but rather from a mini charcoal grill with smoldering coals he had placed in the trunk of the car after leaving a BBQ party.The CO from the incomplete combustion of the briquettes was listed as the source.The windows of the car were all rolled up.


I ran a service call at a house once where the tenants were complaining of headaches.They called the gas company and the technician found high levels of CO in the house, and subsequently turned off and red-tagged the old furnace as the possible culprit.As I was checking the furnace, the occupant said ďDid you hear that?Ē.I said ďHear what?ĒHe said ďOh the kidís playing with remote starter for the SUV parked in the garage.ĒI flipped my lid and gathered the occupants together for a long talk.It turns out that the kid wasnít the only reason for the problem.The kidís mother laid a book on the her purse containing the remote starter once before too.


You canít begin to imagine how much CO a car engine puts out.


I ran a call (I was there 5 times) for a CO detector alarm.Each time I arrived, the CO levels in the house were high enough to sound the audible alarm.But the longer I stayed there, the lower they became.I checked the furnace and water heater flue systems out thoroughly and found no issues.And they werenít using any alternative sources of heat.I finally asked her for specifics about these incidents to attempt to find a pattern.She said that everything was fine until she returned home from running an errand.And there were no incidents occurring overnight.Each time she came home the CO detector was going off.So I finally asked her to explain to me step by step what she did when she left the house.


  1. She went to the attached garage and entered the car and started it up.
  2. She sat in the car and let the engine warm up WITH THE GARAGE DOOR CLOSED


This was a woman with a college degree.(We had a little talk about CO.)


Iarrived at a call for routine A/C maintenance one day and found the homeowner working on his pickup truck in his driveway.The car wasnít in the garage, but the rear end of it was about a foot from the open garage door.As I greeted him, I heard the CO detector in the second floor bedroom of the house go off.He had just put the baby down for a nap in the crib in that bedroom.I had him immediately shut off the truck.And we ran into the house to get the baby out of the room and open all the windows in the house.


(We had a little talk about CO).


I canít think of a better holiday gift than a CO detector.


Areas Served

Greater Kansas City including:

Johnson County, Kansas     Kansas City, Kansas       Kansas City, Missouri

Fairway, KS

Lake Quivira, KS

Leawood, KS

Lenexa, KS

Merriam, KS

Mission, KS

Mission Hills, KS

Mission Woods, KS

Olathe, KS

Overland Park, KS

Prairie Village, KS

Roeland Park, KS

Shawnee, KS

Spring Hill, KS

Stanley, KS

Stilwell, KS

Westwood, KS

Westwood Hills, KS



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Copyright 2007 Leonard Arenson Heating & A/C