{"id":508,"date":"2020-11-23T11:00:00","date_gmt":"2020-11-23T19:00:00","guid":{"rendered":"https:\/\/www.hometownheatingandair.com\/blog\/?p=508"},"modified":"2026-03-18T03:57:47","modified_gmt":"2026-03-18T10:57:47","slug":"why-is-a-cracked-heat-exchanger-dangerous","status":"publish","type":"post","link":"https:\/\/www.hometownheatingandair.com\/blog\/heating-service\/why-is-a-cracked-heat-exchanger-dangerous\/","title":{"rendered":"Why Is a Cracked Heat Exchanger Dangerous?"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"alignright size-medium\"><img loading=\"lazy\" width=\"300\" height=\"225\" src=\"https:\/\/www.hometownheatingandair.com\/blog\/wp-content\/uploads\/2020\/11\/Why-Is-a-Cracked-Heat-Exchanger-Dangerous-300x225.jpg\" alt=\"gas-jet-burners-igniting\" class=\"wp-image-510\" srcset=\"https:\/\/www.hometownheatingandair.com\/blog\/wp-content\/uploads\/2020\/11\/Why-Is-a-Cracked-Heat-Exchanger-Dangerous-300x225.jpg 300w, https:\/\/www.hometownheatingandair.com\/blog\/wp-content\/uploads\/2020\/11\/Why-Is-a-Cracked-Heat-Exchanger-Dangerous-768x577.jpg 768w, https:\/\/www.hometownheatingandair.com\/blog\/wp-content\/uploads\/2020\/11\/Why-Is-a-Cracked-Heat-Exchanger-Dangerous.jpg 799w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><\/div>\n\n\n<p>Are you one of the many homeowners in our area utilizing a\ngas-powered heater for your home comfort in the fall and winter? If you are, then\nthis blog post is for you!<\/p>\n\n\n\n<p>Gas-powered heating systems, specifically furnaces, are the most common type of residential heating system used throughout the country, and for good reason. They\u2019re powerful, effective, and when properly installed and cared for, very efficient. They produce a large amount of heat and do so at less expense than their electric heater counterparts, since natural gas costs much less. <\/p>\n\n\n\n<p>However, while not inherently harmful, <em>any <\/em>natural gas appliance has the potential to develop safety issues. This isn\u2019t said to alarm you\u2014after all, today\u2019s furnaces are built with<a href=\"https:\/\/www.hometownheatingandair.com\/blog\/heating-service\/important-furnace-safety-tips-for-winter\/\"> essential furnace safety tips<\/a> in mind and have features to shut themselves off if they overheat. But something like a cracked heat exchanger, no matter how small the crack is, can lead to harmful CO exposure in your living space. <\/p>\n\n\n\n<h2>When should you call for furnace repair?<\/h2>\n\n\n\n<ul><li>The furnace blows cold or weak air instead of warm air<\/li><li>Unusual noises such as banging, rattling, or screeching during operation<\/li><li>The system cycles on and off frequently<\/li><li>Energy bills increase without a change in usage<\/li><li>The furnace struggles to keep your home at the set temperature<\/li><li>Burning smells, gas odors, or soot appear near the furnace<\/li><\/ul>\n\n\n\n<p>These warning signs often indicate that your heating system needs professional furnace repair. Prompt service repair can restore safe operation, improve efficiency, and prevent more expensive damage to furnace components.<\/p>\n\n\n\n<!--more-->\n\n\n\n<h2>What Is a Heat Exchanger?<\/h2>\n\n\n\n<p>This component is essentially what enables your furnace to heat up the air that travels through its ventilation system. When the burners of your heater come on, they generate hot combustion gas, which is collected inside the heat exchanger. That heat exchanger is a metal chamber or series of clam-shell shaped metal chambers. <\/p>\n\n\n\n<p>The hot combustion gasses inside the heat exchanger heat up\nthe metal walls, and then the blower fan of your furnace comes on to send air\naround the exchanger. The air picks up the heat and continues through your\nductwork. Throughout this whole process, the combustion gas is safely contained\nand then expelled through a flue\u2014unless it\u2019s cracked. <\/p>\n\n\n\n<h2>The Cracked Heat Exchanger<\/h2>\n\n\n\n<p>When the heat exchangers heat up and cool down, the metal\nexpands and contracts. In an aging heater, this can lead to cracks, and those\ncracks can be microscopic in nature. In other words, they can be invisible to\nthe naked eye. But when the heat comes back on, it causes the cracks to widen\nand let out gasses. <\/p>\n\n\n\n<p>Therefore, combustion gasses are able to escape and enter\nyour living space, where it can make you and your family ill. In severe cases,\nCO exposure leads to fatalities. <\/p>\n\n\n\n<h3>\u201cHow Do I Know If I <em>Have <\/em>a\nCracked Heat Exchanger?\u201d <\/h3>\n\n\n\n<p>This is something we\u2019ll check for during your annual maintenance, but it\u2019s never a bad idea to watch and listen for signs, too. A big sign is if you hear a clicking sound coming from the furnace soon after the blower shuts off\u2014one of several<a href=\"https:\/\/www.hometownheatingandair.com\/blog\/heating-service\/5-signs-you-need-furnace-repair\/\"> signs you need furnace repair<\/a>.<\/p>\n\n\n\n<p>Now, we say this with caution\u2014if you\u2019ve always heard a clicking or slight rattling noise from your furnace and you\u2019ve <em>had <\/em>the heat exchanger checked, what you might be hearing is your ductwork fluctuating with the temperature changes. But if you hear a new clicking, or the clicking becomes louder, it\u2019s time to give us a call\u2014especially if you\u2019re noticing other<a href=\"https:\/\/www.hometownheatingandair.com\/blog\/heating-service\/beware-these-furnace-noises-this-heating-season\/\"> furnace noises this heating season<\/a>.<\/p>\n\n\n\n<p>Another sign is that you see signs of corrosion anywhere on\nyour furnace. If there\u2019s corrosion on the outside there may very well be\ncorrosion on the inside. This means your heat exchangers are at risk. It may be\ntime to speak to our pros about a complete system upgrade in this case. <\/p>\n\n\n\n<h2>Frequently Asked Questions<\/h2>\n\n\n\n<p><strong>Question: Can a cracked heat exchanger cause long-term health problems?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> Yes, prolonged exposure to combustion gases leaking from a cracked heat exchanger can impact health over time. Carbon monoxide exposure can interfere with the body\u2019s ability to carry oxygen in the blood, which may lead to symptoms like headaches, dizziness, confusion, and fatigue if exposure continues.<\/p>\n\n\n\n<p><strong>Question: Should you turn off your furnace if you suspect a cracked heat exchanger?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> If you suspect a cracked heat exchanger, it is safest to turn off the furnace and avoid running it until a professional inspection is completed. A damaged exchanger can allow exhaust gases to escape into your home\u2019s air, so shutting the system down reduces the risk of exposure and further damage.<\/p>\n\n\n\n<p><strong>Question: How do HVAC professionals confirm a cracked heat exchanger?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> Technicians use several diagnostic methods to confirm a crack. These may include visual inspections with specialized mirrors or cameras, combustion testing, and airflow analysis. Because small cracks can open only when the system heats up, professionals often test the furnace under different operating conditions to identify hidden damage.<\/p>\n\n\n\n<p><strong>Question: Can a cracked heat exchanger affect furnace performance?<br>Answer:<\/strong> Yes, a damaged heat exchanger can disrupt normal combustion and heat transfer inside the furnace. This may cause the system to operate less efficiently, struggle to maintain consistent heating, or put additional strain on other components, potentially leading to higher energy costs and more frequent repairs.<\/p>\n\n\n\n<p><strong>Question: What steps can homeowners take to reduce the risk of heat exchanger damage?<br>Answer:<\/strong> Regular furnace maintenance is one of the best ways to reduce the risk of heat exchanger problems. Annual inspections help identify airflow restrictions, corrosion, or overheating issues that can weaken the metal over time. Replacing filters regularly and keeping the system properly tuned can also help extend furnace lifespan.<\/p>\n\n\n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can a cracked heat exchanger cause long-term health problems?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, prolonged exposure to combustion gases leaking from a cracked heat exchanger can impact health over time. Carbon monoxide exposure can interfere with the body\u2019s ability to carry oxygen in the blood, which may lead to symptoms like headaches, dizziness, confusion, and fatigue if exposure continues.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Should you turn off your furnace if you suspect a cracked heat exchanger?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If you suspect a cracked heat exchanger, it is safest to turn off the furnace and avoid running it until a professional inspection is completed. A damaged exchanger can allow exhaust gases to escape into your home\u2019s air, so shutting the system down reduces the risk of exposure and further damage.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do HVAC professionals confirm a cracked heat exchanger?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Technicians use several diagnostic methods to confirm a crack. These may include visual inspections with specialized mirrors or cameras, combustion testing, and airflow analysis. Because small cracks can open only when the system heats up, professionals often test the furnace under different operating conditions to identify hidden damage.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can a cracked heat exchanger affect furnace performance?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, a damaged heat exchanger can disrupt normal combustion and heat transfer inside the furnace. This may cause the system to operate less efficiently, struggle to maintain consistent heating, or put additional strain on other components, potentially leading to higher energy costs and more frequent repairs.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What steps can homeowners take to reduce the risk of heat exchanger damage?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Regular furnace maintenance is one of the best ways to reduce the risk of heat exchanger problems. Annual inspections help identify airflow restrictions, corrosion, or overheating issues that can weaken the metal over time. Replacing filters regularly and keeping the system properly tuned can also help extend furnace lifespan.\"\n      }\n    }\n  ]\n}\n<\/script>\n\n\n\n\n<p><strong>For expert <a rel=\"noreferrer noopener\" aria-label=\"heating repair in Pleasanton, CA (opens in a new tab)\" href=\"\/service-areas\/pleasanton-ac-heating\" target=\"_blank\">heating repair in Pleasanton, CA<\/a>  contact <a href=\"\/contact\/send-a-message\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\" (opens in a new tab)\">Hometown Heating and Air Conditioning<\/a>. Your comfort is our business! <\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>It&#8217;s not &#8220;just another component.&#8221; The heat exchanger houses potentially harmful gasses that need to stay out of your living space. <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[76],"tags":[102,103],"_links":{"self":[{"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/posts\/508"}],"collection":[{"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/comments?post=508"}],"version-history":[{"count":6,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/posts\/508\/revisions"}],"predecessor-version":[{"id":1242,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/posts\/508\/revisions\/1242"}],"wp:attachment":[{"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/media?parent=508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/categories?post=508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hometownheatingandair.com\/blog\/wp-json\/wp\/v2\/tags?post=508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}