{"id":538,"date":"2022-02-21T11:00:00","date_gmt":"2022-02-21T17:00:00","guid":{"rendered":"https:\/\/www.moonsair.com\/blog\/?p=538"},"modified":"2026-06-16T22:33:24","modified_gmt":"2026-06-17T03:33:24","slug":"6-reasons-your-gas-furnace-isnt-turning-on","status":"publish","type":"post","link":"https:\/\/www.moonsair.com\/blog\/heating-service\/6-reasons-your-gas-furnace-isnt-turning-on\/","title":{"rendered":"6 Reasons Your Gas Furnace Isn\u2019t Turning On"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"alignright size-medium\"><a href=\"https:\/\/www.moonsair.com\/blog\/wp-content\/uploads\/2022\/02\/furnace-burners-small.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.moonsair.com\/blog\/wp-content\/uploads\/2022\/02\/furnace-burners-small-300x200.jpg\" alt=\"furnace-burners-small\" class=\"wp-image-539\" srcset=\"https:\/\/www.moonsair.com\/blog\/wp-content\/uploads\/2022\/02\/furnace-burners-small-300x200.jpg 300w, https:\/\/www.moonsair.com\/blog\/wp-content\/uploads\/2022\/02\/furnace-burners-small-768x512.jpg 768w, https:\/\/www.moonsair.com\/blog\/wp-content\/uploads\/2022\/02\/furnace-burners-small.jpg 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/figure><\/div>\n\n\n<p>Here\u2019s a frustration you don\u2019t want to run into during the winter: the outdoor temperature has dropped, you\u2019re shivering and so is everyone else in your house, so you set the thermostat to turn the furnace on\u2026 and nothing happens. Maybe the blower fan for the HVAC system activates, but the air coming from the vents is at room temperature. Or maybe there\u2019s no air coming from the vents at all.<\/p>\n\n\n\n<p>What has caused your gas furnace to give up? There are several possible reasons. Some you can troubleshoot, others will require that you call us for <a href=\"\/service-areas\/bossier-city\" target=\"_blank\" rel=\"noreferrer noopener\">furnace repair in Bossier City, LA<\/a>. We\u2019ll look at six potential causes for furnace failure in more detail below.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Common Reasons Your Gas Furnace Won\u2019t Turn On<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tripped breaker<\/strong>: A blown circuit breaker can cut power and make the furnace non-functional.<\/li>\n\n\n\n<li><strong>Clogged air filter<\/strong>: Dirty filters can overload the blower or overheat the heat exchanger, causing the system to shut off.<\/li>\n\n\n\n<li><strong>Tripped flame rollout switch<\/strong>: This safety feature activates when combustion flames escape the chamber, preventing operation until repaired.<\/li>\n\n\n\n<li><strong>Thermostat connection issues<\/strong>: A loose or failed connection blocks the signal to the furnace control board, stopping startup.<\/li>\n\n\n\n<li><strong>Failed ignition system<\/strong>: Modern furnaces rely on electronic igniters; when these burn out, burners won\u2019t light.<\/li>\n\n\n\n<li><strong>Gas flow interruption<\/strong>: Blocked lines, stuck valves, or gas leaks can prevent fuel from reaching the burners.<\/li>\n<\/ul>\n\n\n\n<!--more-->\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. Tripped breaker<\/strong><\/h3>\n\n\n\n<p>Yes, your gas furnace needs to have electricity to run. The blower fan, for example, won\u2019t come on if the HVAC system isn\u2019t getting electrical current, and most gas furnaces use an electronic ignition system to light. A common reason for a furnace to fail to provide <em>any<\/em> action is because an overload has tripped the furnace\u2019s circuit breaker. Check the house\u2019s electrical panel and reset any tripped breakers to see if this fixes the problem.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. Clogged air filter<\/strong><\/h3>\n\n\n\n<p>The air filter for the furnace can cause many difficulties if it\u2019s left in place and becomes too dirty. (We recommend changing the filter every one to three months.) A clogged filter can cause the blower fan to overload its circuit. It can also lead to the heat exchanger in the furnace to overheat because not enough air is moving around it. An overheated exchanger will trip a limit switch and shut the furnace off. Change the filter to see if this gets the furnace back to work.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. Tripped flame rollout switch&nbsp;<\/strong><\/h3>\n\n\n\n<p>This is a safety mechanism that detects when flames from the burners escape from the furnace\u2019s combustion chamber and to outside the furnace. This can happen because the flames aren\u2019t getting enough oxygen and are billowing out to find other oxygen sources. If this switch trips, the furnace may not turn on again until the problem is repaired.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>4. Lost connection with the thermostat<\/strong><\/h3>\n\n\n\n<p>The problem may be due to the thermostat not sending any signals to the HVAC system\u2019s control board. The furnace has to have instructions before it turns on, and if the thermostat has lost one of its connections, nothing will happen. Technicians can repair or replace the thermostat to fix this problem.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>5. Failed ignition system<\/strong><\/h3>\n\n\n\n<p>Furnaces built after 2010 use electronic ignitions systems to light the gas burners rather than a standing pilot light. The igniter can burn out, and when this happens the burners won\u2019t light and a flame sensor will shut off gas flow as a safety measure. Technicians must replace a broken ignition system.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>6. Gas flow problems<\/strong><\/h3>\n\n\n\n<p>The burners may not be receiving any gas. This can happen because of blockage in the gas lines, a stuck valve, or even gas leaks. Please leave anything connected to the gas supply of your furnace to licensed professionals.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Frequently Asked Questions<\/strong><\/h2>\n\n\n\n<p><strong>Question: Why won\u2019t my gas furnace turn on?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> A gas furnace may not turn on because of a tripped breaker, clogged air filter, thermostat connection issue, failed ignition system, flame rollout switch, or gas flow problem. Start with simple checks like the breaker, thermostat settings, and air filter. Leave gas supply and internal furnace repairs to licensed professionals.<\/p>\n\n\n\n<p><strong>Question: Can a dirty air filter stop a furnace from working?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> Yes, a dirty air filter can restrict airflow enough to cause furnace problems. It may overload the blower fan or make the heat exchanger overheat, which can trip a safety switch and shut the system down. Replacing the filter every one to three months can help prevent this issue.<\/p>\n\n\n\n<p><strong>Question: Why does my furnace blower run but no warm air comes out?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> If the blower runs but the air is not warm, the furnace may not be igniting properly. Possible causes include a failed electronic igniter, a flame sensor shutting off gas flow, or a gas supply issue. Because these parts involve combustion and safety controls, a technician should inspect the system.<\/p>\n\n\n\n<p><strong>Question: What should I check before calling for furnace repair?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> Before scheduling repair, check whether the furnace breaker has tripped, confirm the thermostat is connected and calling for heat, and replace a clogged air filter. These are safe homeowner checks. If the furnace still does not start, or you suspect gas or ignition trouble, call a professional.<\/p>\n\n\n\n<p><strong>Question: Is it safe to fix a gas furnace gas flow problem myself?<\/strong><strong><br><\/strong><strong>Answer:<\/strong> No, gas flow problems should be handled by licensed professionals. Blocked gas lines, stuck valves, or leaks can prevent burners from lighting and may create safety risks. If you smell gas or suspect a leak, stop using the furnace and contact a qualified technician or gas provider right away.<\/p>\n\n\n\n<p class=\"has-text-align-center\"><strong>Moon\u2019s Air has provided whole-home comfort since 1971. <\/strong><a href=\"\/contact-us\/schedule-service\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Call us for service today\u2014it\u2019s good to be Mooned!<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>We\u2019ll look at six potential causes for furnace failure in more detail below.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[99,50],"class_list":["post-538","post","type-post","status-publish","format-standard","hentry","category-heating-service","tag-bossier-city","tag-heating-system-repair"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/posts\/538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/comments?post=538"}],"version-history":[{"count":5,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/posts\/538\/revisions"}],"predecessor-version":[{"id":1320,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/posts\/538\/revisions\/1320"}],"wp:attachment":[{"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/media?parent=538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/categories?post=538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.moonsair.com\/blog\/wp-json\/wp\/v2\/tags?post=538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}