CO Puts Contractors in a Tight Spot

How the correct prevention and detection practices can keep contractors out of lawsuits.

One of the biggest threats to the HVAC contractor is one that is seldom given the attention that it deserves -- carbon monoxide. Unlike other challenges faced by contractors and their technicians, inattention to possible CO problems can lead to illness and death for their customers and put contractors and technicians at risk.

Some Examples

The Lofgrens, a family of four, won a vacation to Aspen, Colorado that included accommodation in a three-bedroom house. They went to bed the first night and were all found dead by friends the next day. The problem? An elbow to an exhaust pipe for a gas-fired boiler wasn’t glued when installed and somehow disconnected.

In Denver, Lauren Johnson, a 23-year old graduate student, was found dead on the floor of her apartment from CO poisoning. The source? A technician repairing the flue vent used the old cap and did not install it properly.

In Florida, an elderly woman returned home one night and forgot to turn off the car, leaving it running in the garage. The CO fumes entered the house through and air-conditioning unit and its air handler, killing the woman and her husband.

What is the result of these and most other CO-related deaths? Devastating lawsuits. Even for the car left running in the garage. Both the manufacturer of the air conditioner and the HVAC contractor in that case settled for substantial sums.

CO kills more than is commonly thought. For more information on CO-related deaths go to, the web site of the non-profit Carbon Monoxide Safety Organization (COSA) and click on CO News.

Improper Installation
While we like to think most contractors and technicians are conscientious and thorough, the opposite is the case according to Bob Dwyer, director of training for COSA.

“A great many contractors just install a furnace and leave,” said Dwyer. “They don’t test and verify that the system is running according to manufacturer’s specs on the data plate. The manufacturers don‘t help the situation. All they require is the model, serial number, and date of installation. It would be much better if the manufacturer required proof that the system was running to spec. These are not turn-key systems. They need to be checked and adjusted after installation, otherwise they are potential sources for carbon monoxide in the home.”

“I tell all the new guys in training that this isn’t just a paycheck job,” Said Scott Catalano, a certified furnace technician in Beacon, NY. “I tell them that you hold people’s lives in your hands. That they have to be careful on every job and double check everything, no short cuts. Way too many don’t care and that’s when people can die.”

CO Sources
So, what needs to be done? First, technicians need to keep firmly in mind the potential sources of carbon monoxide. It’s not as obvious as some think. The EPA offers this list of sources on its web site:

“Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke. Incomplete oxidation during combustion in gas ranges and unvented gas or kerosene heaters may cause high concentrations of CO in indoor air. Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces) can be significant sources, or if the flue is improperly sized, blocked, disconnected, or is leaking. Auto, truck, or bus exhaust from attached garages, nearby roads, or parking areas can also be a source.”

Clearly the sources that most affect HVAC contractors are those related to furnaces and boilers. As mentioned above, one of the most critical times for minimizing CO is during installation.

An Installation Solution
“It’s a simple matter of combustion analysis,” said Dwyer. “There are several combustion analysis instruments available that enable a technician to assure that a system is running to manufacturer’s specs.”

Brent Hettinger knows there are always shortcuts in the field, but doesn’t think the problem with lack of combustion testing is quite that dire. Hettinger designs complete heating systems for George T. Sanders, a large Colorado heating and plumbing supplier. He not only designs the systems, including piping and electric, he also oversees their installation and assures that proper combustion analysis is performed on the completed system to bring it to manufacturer‘s specifications for everything including CO. He recently discovered a new tool that will really help his technicians in the field.

“It’s a hand-held instrument that basically takes the tech by the hand and leads him through each step of combustion analysis, among other things,” he said. “More important, when the SAVE button is pressed, it records each test in its memory and its results so that we have a record of what was done and we can be sure it was done right. It is available with multiple test heads including one for combustion measurements and another for CO in the flue. When you take the measurements, the HVAC Guide system analyzer enters the results directly into the meter‘s memory. Back at my office, I can download the test results into my computer and can print out reports. If a technician has to go back to the site at a later date, I can load the results back into the meter to compare with the new measurements.”

“The key to this instrument’s capabilities is the firmware,” said HVAC Guide product manager Russell Harju. “It leads the technician step-by-step through combustion analysis, superheat, subcooling, and target evaporator exit temperature. It’s very easy to use and all the necessary tables are built right in, so the technician will not have to carry different tables and charts for each test. It stores up to 200 tests that can be downloaded to a PC. It saves all of the tests, enables the contractor to perform thorough customer tracking, and creates a work order that can be given back to the customer. Upgrades and updates are available online so, as new tests are developed, they can be uploaded from the instrument’s web site to the HVAC Guide.”

Other CO Sources
While proper installation is important, there are of course other sources. Clogged flues, cracked heat exchangers, and poor venting are the obvious ones. One of the worst is an unbalanced house where the furnace or boiler is competing with the building for air. Since the house almost always wins, the negative pressure sucks CO down the flue and into the house.

“Even if the system is installed with no testing and verification and is running at 50 percent of what it should, it is probably not putting CO in the house,” said Erik Rasmussen, international programs manager for COSA. “But if it is competing with the house for air, then you have CO trouble big time.”

David Richardson is a certified CO and combustion analyst. He calls it the ‘stack effect’.

“With the stack effect the building is competing for airflow with any of the combustion appliances in the building. The building will many times win in this scenario for draft competition. The building becomes a bigger chimney and air flow follows the path of least resistance.”

“It’s a building shell issue and, often, a quality of life issue,” said Dwyer. “The best way to address the problem without disturbing quality of life is to isolate the furnace or boiler and give it it‘s own air supply.”

Detecting CO
How does the home owner know if a building has a CO problem? They don’t. It’s odorless and many of symptoms of excessive CO mimic the symptoms of flu. Itchy eyes, shortness of breath, mild nausea, and mild headaches. Moderate levels of CO exposure can cause death if the symptoms persist for a long measure of time. Most doctors confuse mild CO poisoning to flu.

CO alarms aren’t much use, either. Most don’t send an alarm unless there has been a level of 70 parts per million present for more than four hours. How bad is that? OSHA’s maximum CO level for the workplace is 35 parts per million. Most firefighters are under instruction to put on their breathing equipment on at 25 parts per million. So a home owner can get very sick before their alarm goes off.

George Kerr is the owner of CO-Experts and this year was given the Lifetime Achievement Award by COSA for his work promoting CO safety. Many refer to him as the Godfather of CO. He finds the vast majority of today’s CO alarms to be woefully inadequate.

“The problem is with Underwriters Laboratories (UL). They have a standard for CO alarms that is actually dangerous,” he said. “More and more studies are showing that at-risk people are adversely affected by very low levels of CO. One UCLA study showed that exposure of pregnant women in the third trimester to levels as low as 25 ppm resulted in underweight babies, with smaller head sizes as well as some other serious birth defects in the newborn.”

To show how serious the problem of CO alarms has become, one manufacturer puts this disclaimer on one of their alarms:

"Pregnant women, infants, children, senior citizens, persons with heart or respiratory problems and smokers may experience symptoms at lower levels of exposure than noted. Individuals with medical problems may consider using warning devices which provide audible and visual signals for carbon monoxide concentrations under 30 ppm."

So, it’s up to the contractor and the technician.

“This is an obvious step,” said Rasmussen. “The technician should measure the CO level before he enters a home and then again after entering. If he gets a zero reading outside and a 5 parts per million inside, that CO has to be coming from somewhere in the home and someone had better find it.”

Rasmussen insists that the technician be equipped with an electrochemical sensor.

Adolfo Wurts agrees. Wurts is the engineering manager at Fieldpiece Instruments, a company that manufactures meters and tools solely for HVACR use, and he has done extensive research and development on CO detectors.

“The electromechanical sensor is faster and more accurate than other methods,” he said. “You should look for a detector with features designed for the HVAC environment: rapid response and ease of calibration, audio and visual alarms, an alarm rate that increases as you approach the source, a MAX hold to help you zero in on the source, and the availability of a pump for flue gas testing.”

Some say the problems of installation related to CO contamination are caused by the contractor’s desire for more jobs in a day, hence more profit. But Rasmussen doesn’t see it that way.

“It’s a matter of education and test,” he said. “Most contractors don’t realize the problems with CO and the consequences. The important part is that once they do realize the importance and start testing for CO on every call, they will actually make more money. If CO is detected, they report to the home owner and they repair the problem. Not only is that more profit, it gives positive reinforcement to the home owner. When a system is installed correctly, they have fewer call backs. That’s the same as more profit.”

“I wear a CO detector on my belt everywhere I go, and you would be amazed at the readings I get,” said Dwyer. “Recently, in a restaurant I got a reading of 25 parts per million and brought it to their attention. It turned out a new exhaust fan in the kitchen had been cross-wired. Over time that level would have climbed and a lot of people would have gotten sick.”

Last year in Havertown, Pennsylvania, 30 people were taken to the hospital for CO poisoning. It started with an elderly woman who had collapsed. Much more damage would have been done if the EMT who arrived to take care of the lady didn’t have a CO detector attached to the outside of his gear bag. The cause turned out to be a bakery in the mall running with the exhaust fans off.

So, not only is constant CO monitoring a health benefit for a contractor’s customers, it is also an opportunity for more profit and increased client approval.

Jack Sine is a freelance writer specializing the HVAC/R market place. He can be emailed at [email protected] or called at 845-831-6578.

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