Is your furnace blowing cold air? 2. If your issue continues, call our team in Tacoma, WA. Or, if your system has not been cleaned in a while, a valve could be stuck due to dirt and debris. This usually arises if you haven’t changed your air filter routinely. Again using Occam’s Razor, we can assume that the next likely culprit for your heater blowing cold air is your thermostat. If you have a newer furnace with an electronic control panel, you may need to reset the system. This problem requires a visit from your HVAC repair technician. All Rights Reserved. Inadequate gas supply. If you’ve had the thermostat for a while, the battery might be low. Common Ignition Problems. If leaks are excessive, you may want to consider sealing your ducts. The thermocouple is a sensor that controls the gas valve and ignition. Even worse, the furnace is blowing cold air! This means the fan will run continuously without providing heat. Do this: Turn off your furnace at the thermostat, and check the furnace … Now let’s talk about an even more common reason a furnace might blow cold air: you’re using the wrong fan settings. Consult an HVAC expert for advice. Check your air filter. Afraid it’s too expensive? 13 Common Causes. We use cookies to give you the best possible experience on our website. But, if the switch is bad, they’ll need to replace it. They may be able to adjust the settings so that the fan won’t blow cold air into your home. You Own a High-Energy, Two-Stage Furnace. That cold air mixes with the warm air from your furnace, causing the air coming from your vents to feel considerably cooler than it should. See our response to recent issues regarding COVID-19. You also don’t want to risk frozen pipes. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack. Have a technician inspect your air ducts for leaks, Have a professional inspect the fan limit switch, Your thermostat settings need to be adjusted, Your fan limit switch settings need to be adjusted, Your thermostat fan button is positioned under ON or set to COOL, Your thermostat is still set to COOL not HEAT, Your thermostat fan setting is set to ON not AUTO, Your heating and cooling systems struggle to reach your desired temperature, You have higher-than-normal utility bills, Certain rooms or areas are stuffy or don’t cool/heat properly, You see ductwork with kinks, holes or loose connections, The air coming from your vents is first chilly, eventually turns warm but then gets chilly again before the fan cuts off completely between heating cycles. What Can I Do If My Heater Is Blowing Cold Air? What’s wrong? 13 reasons your furnace is blowing cold air 1. In some cases, you may be able to fix the problem yourself. Even if your furnace is fairly new, things can go wrong that cause this unpleasant surprise. If this is the case, you can simply switch the setting from "on" … If your fan only runs when your furnace is heating the air, then you’re much less likely to experience your furnace blowing cold air. Turn off power to the furnace at its ON/OFF switch. Have an expert inspect your ducts along with the furnace. If your thermostat is set to "on" instead of "auto," it could be causing your furnace to blow cold air. If your furnace continues to blow cold air then you should check if you have a two-stage furnace. If you’re still not getting warm air from your furnace, we can help. Do you have thermostat wars going on in your office? If your furnace fan is set to ON, the fan runs continuously, whether or not your furnace is producing heat. If your forced-air gas furnace is blowing cold air, a number of factors could be to blame—many of which you can address on your own, without the immediate help of a service professional. Is the Pilot Light lit? If everything seems to work properly, and then your furnace blows cold air back and forth until it switches off, you may be faced with a furnace that has overheated. Go to your thermostat. Thermostat: A Furnace Blowing Cold Air Could be Due to Your Thermostat. If this doesn’t fix your problem, and your furnace is still not blowing hot air, you can move on to some of the other potential culprits. Furnaces can overheat for a variety of reasons, including: So, how do you know which problem is causing your furnace to blow cool air? Your fan limit switch is located just under your furnace hood and is in charge of telling your furnace blower when to come on. That’s why the furnace is not blowing hot air. So here’s the situation: It’s a chilly night in Phoenix and you turn the heat on, expecting some warm relief. If your furnace overheats, it could end up blowing cold air. Heat Pump Troubleshooting: 3 Common Problems and Solutions, The Rewards of Giving Back: Arista Team Rebuilds a Home in Puerto Rico, Commercial Refrigeration Service & Repair. Instead, you’re blasted with cold air. Your furnace’s limit switch, which specifically works as a safety measure, has turned your furnace burners off until the unit reaches a safe temperature. When the chilly weather finally arrives, and you have to turn on your furnace for the first time after many months of non-use, the last thing you want to find is that it’s not working. Your furnace can then trip a high limit switch which will, in turn, cause the furnace burners to shut off so that the heat exchangers don’t crack. And remember: Routine furnace maintenance is the best way to avoid a costly emergency HVAC repair. If not, the compromised air flow can cause your furnace to overheat, shutting down the burner. In furnaces, most heat exchangers, depending on brand and size, get up to 140-170 degrees Fahrenheit. If the pilot won’t light at all, you may have a faulty gas valve. If the furnace still blows cold air, call in a professional. If your ducts are leaking (and ENERGY STAR says that almost all homes leak about 30% of the air in their ducts), cold outside air is making its way into your ductwork. Change the setting back to AUTO, and you’ll have heat again. If the furnace is cold, it cannot heat the air being propelled outside. Well, lucky for you, that’s where we come in. If the furnace burner itself is neglected, accumulated dust and grime can cause trouble igniting. December 16, 2020. A flame sensor that’s covered with grime or worn out can cause the burner to keep shutting off. Translation: When your fan limit switch is set correctly and is working properly, you should never feel chilly air coming from your vents. From dirty air filters to broken thermostats, these are the most common causes of problems. So, how do you know which problem is causing your furnace to blow cool air? Just contact us. When a furnace blows cold air, there may be an issue with the unit’s electronic control panel. When a heating cycle begins and your air handler turns on, that cool air will blow out of your registers before warm air does. The lukewarm air coming out of your furnace can also be the result of leaky air ducts. A furnace that isn’t getting fuel will not ignite and will blow only cold air. 1. This can cause the air to … Other thermostat issues. Have you changed your air filter lately? You’ve got three basic options. HVAC Preventative Maintenance Contracts: How to Find the Right One for Your HVAC Infrastructure. Check that all supply vents are open. Leaks in your ductwork means that cold, unconditioned air from inside your attic gets sucked into your ductwork. © 2021 Patrick Riley, LLC. If not, call a professional. If you have an older furnace with a continuous pilot light, the pilot may have gone out. Large holes and leaks in air ducts can make it seem like your furnace … This can cause your furnace to lock down for safety. Try changing the batteries. If yes, our team in Conway, SC, suggest checking a few things first and then call us for help. And because your furnace is no longer heating, the air being pushed into your home will be cold. When your furnace isn’t running, the air in your ducts cools down. When the fan is on, the furnace will continue to blow, regardless of whether or not the air is being heated. Major duct problems. Source. So you’ve turned on your furnace, but it’s giving you the cold shoulder by blowing cold air. 2. If you haven’t done that yet this winter, call in an HVAC service expert to keep your system in top shape and prevent unexpected failures. If you have a newer furnace with an electronic ignition, such as an intermittent pilot or a hot surface ignition, your system may need adjustments or replacement of failed parts. IAQ and Mold in NYC Buildings: Are Kids at Risk. But here are 3 common causes you can fix yourself. 3. Here’s another possible DIY fix for your heater blowing cold air. If you know how, you can clean or replace the filter yourself, but it’s messy and not as easy as an air filter so you may want to leave this job to the pros. So what’s the problem? If your furnace is blowing cold air, not blowing any air at all, or making odd noises, it’s important to schedule a repair as soon as possible. If your ducts have cracks or worse, then the cold air blowing into your house might be coming straight from outside right into your ducts, mixed in with the warm air your perfectly functional furnace is producing. New furnaces are equipped with a spark ignitor or electronic ignition, which may require a technician to repair. A dirty air filter blocks airflow over the furnace’s heat exchanger, causing it to overheat. Here in the New York City area, we’re all pretty tired of the cold weather by now. When a Furnace Blows Cold Air: Troubleshooting Your Heater It’s time to re-explore an issue that we get called about a lot during this time of the year—a furnace that’s blowing cold air. But if you close too many, it increases pressure inside the duct system. Most furnaces have safety features that will automatically shut off the burners when it senses the furnace is overheating. If you know how and you’re comfortable doing it, you can try to relight the pilot yourself. Wait a few minutes, then flip the switch to ON. No matter how you travel to work, whether it’s by bus, car or train, your commute probably ends with a cold walk in the icy wind. So, if you have a tripped breaker, the furnace may stay on however, the air can’t warm up because the gas burner can’t ignite. If so, your blower may keep circulating cold air even after the burners fail to light and produce heat. Have a professional inspect the fan limit switch. If the filter becomes clogged, the unit can start to overheat and cause the burner to shut down. There are seven types of problems that can cause your furnace to blow cold air. Ensure that your thermostat is set higher than the temperature in your home. This is usually a simple fix, but you’ll need to call a technician to adjust or replace it. Check the furnace’s air filter. If gas supply is interrupted for any reason, the gas furnace pilot light will go out. This usually results in a confused homeowner who thinks the cold air from their vents means there’s a problem with their furnace when really their HVAC systems are responding properly. 6. Count your blessings that this time you avoided an expensive furnace repair. There are several possible causes for a furnace blowing cold air, so it’s hard to give you advice without more information. To troubleshoot a misbehaving gas furnace, start with the easiest explanations and solutions, then work your way to the most complicated. This “hot then cold air” sequence happens over and over and your home isn’t warming up. ... Start by taking a look at the limit switch. If the filter looks like the filter to the right in the picture below, replace it. When you get to your destination, you expect to walk into a toasty warm space. Learn more from our free guide: HVAC Preventative Maintenance Contracts: How to Find the Right One for Your HVAC Infrastructure. But you need to know when to call in the furnace repair pros so you don’t have to spend unnecessary time in the cold and interrupt your business. That may be a quick and easy fix. Make sure your thermostat is set to HEAT and your fan is set to AUTO. Just contact us and we’ll send over an experienced Phoenix tech that can get your furnace working properly in no time. Your gas supply could be turned off. When the filter is clogged, ignition can be affected and the result is your heating not blowing hot air. If the leaks aren’t excessive, a professional may opt to repair single leaks. If your furnace is blowing cold air, check your thermostat, air filter and ductwork. Have your system cleaned and checked by an HVAC professional. Without the cooler air of your home flowing through it and keeping the temperature steady, it will continue to burn hotter and hotter, reaching a temperature of 180-200 degrees. Otherwise your electric heater or gas furnace will not turn on. It is usual for cold air to enter the heating system until it is warm, and then for warm air to continue to blow after the air heats up. Many of the causes of furnace problems can be prevented with regularly-scheduled cleaning and maintenance. Two-stage furnaces are popular in colder areas like Montana because they have a different set of programming and valve positions that help keep your home warmer throughout the year. This is of course a very unsettling problem and not one that you want to face. If you have an oil-fired furnace, you may be out of fuel. COVID-19 & Your HVAC System: Your Questions Answered. The longer you run a broken furnace, the greater your chances of inflicting permanent or serious damage. This is sometimes easily solved by resetting the system. If your furnace is overheating, that means your heat exchanger is getting too hot. If you don’t know what a pilot light is, it’s a small flame that runs at all times in order to light the burners in your furnace. 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