The Hidden Carbon Monoxide Risk in Philadelphia’s Older Homes: Q&A With Chimney Expert Joe Ochal
Photo By: chris robert
As temperatures begin to fall, homeowners across the Philadelphia region are preparing furnaces, fireplaces and other heating systems for another winter. But in some of the area’s oldest homes, one of the most important components of that heating infrastructure may have gone decades without being evaluated.
Chimneys do more than carry smoke from a fireplace. In many homes, they also vent combustion gases produced by furnaces, boilers and other fuel-burning appliances. When the interior of an aging chimney deteriorates, those gases may no longer travel safely out of the home.
That deterioration can be difficult to spot from the outside. A chimney may appear structurally sound while its internal clay liner is cracked, damaged or beginning to collapse. In a century-old home where the chimney has never received a professional inspection, problems can develop for decades before homeowners know they are there.
The issue becomes particularly important as heating systems return to regular use during colder weather.
Joe Ochal, founder and CEO of Chimney Scientists, works with homeowners throughout the greater Philadelphia region and has seen how aging chimney systems can create ventilation and carbon monoxide concerns. We asked Ochal what homeowners in older properties should understand about their chimneys, what inspectors should be looking for and why an overlooked problem can become a winter emergency.
1. Philadelphia has one of the country’s oldest housing stocks. What makes older homes particularly vulnerable to carbon monoxide problems?
Joe: The majority of homes in Philadelphia use a traditional chimney system to vent their heating appliances. Chimney heating systems start to break down internally after 30 to 40 years. This can lead to holes where carbon monoxide can go into the walls. Many chimney systems are not checked for 50 or even 100 years. Eventually, they cave in on themselves and then this will cause a blockage or carbon monoxide will back up into the basement and the heating system will stop working.
2. You’ve noted that roughly two out of three homes Chimney Scientists services for chimney cleanings show evidence of improper or dangerous carbon monoxide venting. What specific issues are your technicians typically uncovering when they find those situations?
Joe: The interior of the chimney will have holes or carbon monoxide will escape into the wall cavity on the first or second floor. Additionally, the interior clay pipe inside the chimney that drafts all of the gases acts like a straw, and once the straw starts to get holes in it, it doesn’t perform as well. Some of the gases never make it fully out of the chimney, and they leak back into the basement, so typically we will run a carbon monoxide test in the basement around the heating appliances. This is where we can most commonly find carbon monoxide related to poor chimney construction.
3. Many homeowners associate chimneys exclusively with fireplaces. What other household appliances depend on a chimney or flue system to safely remove combustion gases?
Joe: Your home heating system. You may have natural gas, propane, or oil to heat your house. This could also be a woodstove or a gas fireplace that utilizes a chimney system.
4. Why can a chimney look completely intact from the outside while still creating a serious carbon monoxide risk on the inside?
Joe: The degradation on the interior can be masked by the good condition of the exterior. For example, you can have mold or rot behind the walls and not realize it until you cut open the drywall.
5. What subtle warning signs or red flags should homeowners look out for that indicate something might be wrong with their chimney or ventilation system?
Joe: Honestly, there’s not much that you can look out for. Your carbon monoxide detectors will not go off for anything less than 120 ppm. 1 ppm is not good for your health, while 5-10 ppm causes sluggishness and headaches over time.
Carbon dioxide is often referred to as the “silent killer.”
6. How can a hidden ventilation failure suddenly turn into a heating or hot water emergency during the winter months?
Joe: The inside of the chimney has been degrading for years, completely unchecked, and eventually the interior clay pipe of the chimney that vents all of the gases caves in on itself inside the wall and causes a blockage. Eventually, all of the carbon monoxide and combustion gases back up into the basement where the appliances are.
7. How often should homeowners have their chimney and venting systems evaluated, particularly in older regional homes?
Joe: The Chimney Safety Institute of America recommends having your chimney inspected and cleaned annually.
We see so many chimneys that are completely falling apart for heating appliances. However, most of our customers will have chimneys that are 50 or 100 years old that were never inspected and they’re actively using them all winter long,
One inspection is the difference between an emergency call for carbon monoxide and not an emergency call.
8. What should a homeowner specifically ask an inspector to evaluate beyond simply whether the chimney needs a standard sweeping?
Joe: If they are performing a camera inspection, an exterior, or drone inspection.
9. If someone lives in a century-old home and has never had the chimney system professionally evaluated, what is the single most important thing they should know before turning on their heat this season?
Joe: Old chimneys for heating appliances cave in on themselves all the time in Philadelphia. There are easily 24 chimney companies in this region. They’re working around the clock in the winter, often on calls for caved-in chimneys for heating appliances.
The Bottom Line for Older Homes
The condition of a chimney cannot always be determined by what homeowners can see from the roofline or fireplace. In older Philadelphia homes, the more consequential deterioration may be occurring inside a flue that has been carrying combustion gases for decades.
That makes professional evaluation particularly important for homeowners who do not know when their chimney was last inspected. As Ochal’s experience illustrates, discovering a deteriorating liner before the heating season is very different from discovering it after a blockage or ventilation problem has already disrupted the home’s heating system.
With furnaces, boilers, fireplaces and other fuel-burning appliances returning to regular use, the chimney should be considered part of the home’s heating and ventilation infrastructure rather than simply a feature of the fireplace. For owners of century-old properties in particular, knowing what is happening inside that system can be one of the most practical steps to take before another winter begins.
