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Vince DiFilippo, president and owner, DiFilippo’s Service Company, received a rather strange request from a close friend. The man shared that his dog was sick, stumbling around, and having a difficult time descending the stairs. Additionally, he stated his daughter was dealing with a long-term illness, plagued with nausea, overcome with headaches, and vomiting intermittingly. Oddly enough, away from the home, the girl seemed fine.

While not a veterinarian or physician, DiFilippo agreed to take a look. Upon entering the home, his pocket carbon monoxide (CO) meter triggered incessantly.

“The boiler was located in the basement, which also served as a home base for the family’s pet cats,” said DiFilippo. “We discovered the boiler was stuffed with cat hair and was pushing out carbon monoxide fumes. Those fumes were vented up into the daughter’s bedroom, and, of course, she slept with her door shut every night.”

He shut the system down immediately.

After a brief visit to the local hospital’s hyperbaric chamber, the girl’s health returned. DiFilippo’s techs addressed the issue, cleaned out the system, and returned it to working order. Most importantly, the contracting company’s brisk actions potentially saved the family from a fatal catastrophe.

 

The Silent Killer

Carbon monoxide (CO) is a colorless, odorless, tasteless gas that is created as a byproduct of combustion. Mild exposure can cause symptoms, such as nausea, dizziness, or headaches, while severe poisoning can result in brain or heart damage or even death.

Comfort equipment, such as gas furnaces, boilers, and water heaters, are primary emitters of CO. As a result, testing residential equipment for CO leaks often falls on HVAC technicians. However, due to a lack of training, time constraints, and numerous other reasons, many HVAC contracting companies are not performing combustion testing, potentially compromising customers’ safety.

 

Where to Begin

“The HVAC industry is the nation’s first line of defense when it comes to CO poisoning,” said David Richardson, vice president of training, National Comfort Institute (NCI). “HVAC technicians are inside more homes on a regular basis than any other industry. It’s our responsibility to detect this problem.”

Richardson insists all HVAC contracting companies should be testing and diagnosing combustion leaks, though, for many companies, the biggest challenge lies in knowing where to begin.

“Start small with training,” said Richardson. “If you have a larger company, pick a few top technicians and get them trained so they can help lead the effort. If you’re a smaller company, everything will fall on you, as the owner, to lead the way. Getting started may seem overwhelming at first but is easier if you take it one step at a time.”

DiFilippo’s Service Company took an all-encompassing approach, insisting every technician attends and gains certification through NCI’s Combustion Performance and Carbon Monoxide Safety course.

“Company-wide certification builds pride and morale,” said Vince DiFilippo. “It grants us the ability to solve the client’s combustion problems better than anyone else. Every furnace we install includes a low-level CO monitor, regardless if it’s an 80% or 90% unit.”

Jose Montez, marketing manager, Kennihan Plumbing, Heating, and Air Conditioning, Valencia, Pennsylvania, said his company offers internal combustion training, though, he admits, training new technicians can be an uphill battle.

“Some of the new techs we bring in simply aren’t educated on combustion testing,” he said. “We have to spend quite a bit of time acclimating them to the process. We expect to see CO readings in every report, and techs catch flak if they skip over this because we feel it’s a very important part of the job.”

 

Condemning a System Due to Combustion

When examining a unit for potential signs of combustion, several visual clues can serve as tell-tale signs that combustion is present.

“When the blower comes on, if there’s any flame waiver, that’s a sign that the heat exchanger may be cracked,” said Richardson. “A cracked heat exchanger is dangerous because it can influence proper combustion and create unsafe conditions. If a tech encounters a cracked heat exchanger, it’s very important to figure out why it’s cracked and proceed accordingly.”

Rusty Flue Vent.

VISUAL CLUES: Rust is the No. 1 sign of improper venting of flue gases. (Courtesy of National Comfort Institute)

Rust is the No. 1 sign of improper venting of flue gases and pooling water is also a cause for concern, said Richardson.

“When it comes to water heaters, melted rings or rust around the draft hood are signs of combustion,” he said. “Soot is carbon in its purest form, so watch out for that as well.”

If a tech encounters a system emitting dangerous levels of CO, he or she should immediately shut down the system and encourage the homeowner to seek additional action. Of course, condemning a system immediately draws questions and concerns, oftentimes leading to angry and confused customers.

“If a furnace is emitting more than 100 ppm, we evacuate the space, and if it’s over 400 ppm, we disable the furnace and shut it down immediately,” said Scott Getzschman, president, Getzschman Heating in Fremont, Nebraska. “Our techs are then challenged to diagnose exactly why the equipment is faulty. Is it dirt, air, etc.? It’s our job to figure that out.”

It can be challenging when a homeowner calls an HVAC company in for a tune-up, thinking he’s doing the right thing, only to be told his system needs to be shut down and replaced, said Getzschman.

“These types of conversations usually include strong emotions,” he said. “Customers think they’re doing the right thing by keeping up with their system only to be met with a much larger need. In these cases, it’s important to remind customers that these decisions are made with respect for their safety.”

Tyler Nelson, instrumentation and industrial sales manager, Sauermann, said combustion numbers tell a concrete story that shouldn’t be disregarded.

“In sports, your record is evidence of what you are,” he said. “And, when it comes to combustion, the numbers don’t lie. Techs should be upfront with customers about what the combustion analysis reveals and define why they’re offering a specific repair. Tell them exactly how the repair works and how the equipment will function after the repair is completed. When they’re all done, run the combustion test again and show them the resulting improvements.”

To protect yourself from liability and potential reputation smearing, Nancy McKeraghan, co-owner, Canco Climate Care, Ontario, Canada, said it’s important for contractors to document and retain every measurement they take.

“As contractors, we need to be evidencing everything we do,” she said. “Third-party documentation is crucial for your credibility. Make sure you’re sharing that the actions you take are not your opinions but rather are dictated by the equipment manufacturer or regulatory body.”

Dan Squires, president, Vincent’s Heating & Plumbing Inc., Port Huron, Michigan, carries around a FAQ sheet that defines each authority’s direction on combustion.

“Customers will often say, ‘You’re shutting this down per what authority,’ so I come prepared,” he said. “The American Gas Association [AGA] says any visible crack or hole in a heat exchanger requires either a replacement heat exchanger or furnace. The Technical Standards and Safety Authority [TSSA] states, where the heat exchanger is found to be defective, it shall be replaced. The National Fire Protection Association [NFPA] 54 - National Fuel Gas Code states, if it is determined a non-safe condition exists, the unit should be shut off and the owner be advised of the unsafe condition. These aren’t my words. These are the rules and regulations as presented by the authorities.”

 

Conclusion

To succeed in combustion testing, you must stay consistent and believe in what you’re doing. This is not some silver bullet you plug-in like a store-bought carbon monoxide alarm. Instead, it’s a specialized service that reaps benefits for customers and contracting companies.

“Your customers must trust you, so don’t use scare tactics to promote these services,” said Richardson. “Instead, educate and inform from a position of integrity, honesty, and concern. You’ll find word spreads fast as you solve problems that your competitors attempt to solve with guesses and assumptions.”

 

Ambient CO and Recommended Actions

The following guidelines offer general advice on how

  • 0-9 ppm: These are considered normal levels within the home. If there are no smokers, however, investigation is recommended. These levels are measured above ambient levels in most cases because the CO instrument has been zeroed in outdoor air.
  • 10-35 ppm: Advise occupants of the level, and ask them about possible symptoms (slight headache, tiredness, dizziness, nausea, or flu-like symptoms). Check all unvented and vented appliances, including the furnace, water heater, and boiler. Check for other sources, including attached garages or small engine operation.
  • 36-99 ppm: Recommend fresh air; check for symptoms; ventilate the space, recommend medical attention.
  • 100 ppm and higher: Evacuate the home (including yourself) and contact emergency medical services. Do not attempt to ventilate the space. Short-term exposure to these levels can cause permanent physical damage.