If you did it yourself instead of calling a professional, you may have chosen a thermostat that’s not compatible with your heating system. Your furnace is a controlled fire burning inside your home. 13 reasons your furnace is blowing cold air 1. And because your furnace is no longer heating, the air being pushed into your home will be cold. In furnaces, most heat exchangers, depending on brand and size, get up to 140-170 degrees Fahrenheit. If your issue continues, call our team in Tacoma, WA. Pilot Light. When your furnace isn’t running, the air in your ducts cools down. Have a technician inspect your air ducts for leaks and provide the best solution. Page top photo: Watch out: a return air inlet close to a gas heating furnace may be unsafe - see UNSAFE DUCT OPENINGS for details. You’ll need a visit from an HVAC professional to make this furnace repair. If yes, our team in Conway, SC, suggest checking a few things first and then call us for help. 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. When you get to your destination, you expect to walk into a toasty warm space. Well, lucky for you, that’s where we come in. ... Start by taking a look at the limit switch. Count your blessings that this time you avoided an expensive furnace repair. Furnaces can overheat for a variety of reasons, including: They may be able to adjust the settings so that the fan won’t blow cold air into your home. If so, your blower may keep circulating cold air even after the burners fail to light and produce heat. Ensure that your thermostat is set higher than the temperature in your home. 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. 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. Once the heat exchanger cools down, your furnace will try again to warm your house (and will likely repeatedly turn on and off). HVAC Preventative Maintenance Contracts: How to Find the Right One for Your HVAC Infrastructure. Here in the New York City area, we’re all pretty tired of the cold weather by now. How Does Workplace Ventilation Impact Employee Productivity? If the furnace is cold, it cannot heat the air being propelled outside. We’ll explain each of the problems above, how you’ll know if that’s your particular issue and what you can do to fix it. What’s wrong? If the furnace still blows cold air, call in a professional. Furnace Blowing Cold Air? Basically, the furnace isn’t lighting the fuel, meaning it can’t heat your home, either. Well, it could be multiple issues; some of them you can solve yourself. This is of course a very unsettling problem and not one that you want to face. Otherwise your electric heater or gas furnace will not turn on. This means the fan will run continuously without providing heat. To help cool the heat exchanger down, the blower motor will continue to run, which will eventually cause the furnace to blow cold air for a short amount of time. Turn off power to the furnace at its ON/OFF switch. Consult an HVAC expert for advice. If your furnace fan is set to ON, the fan runs continuously, whether or not your furnace is producing heat. Meanwhile, you’ll get cold air because the fan continues to run as a safety measure, even after the furnace isn’t producing heat. 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. If you know how and you’re comfortable doing it, you can try to relight the pilot yourself. This could happen from a gust of air caused by someone working near the furnace. Try changing the batteries. Check that all supply vents are open. Unfortunately, you’ll need a professional to fix this problem. If you have an older furnace with a continuous pilot light, the pilot may have gone out. Afraid it’s too expensive? Check your air filter. Change the setting back to AUTO, and you’ll have heat again. Why Is My Furnace Blowing Cold Air? Your furnace blows hot air but that air quickly turns cold then the furnace shuts off altogether. 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. This is usually a simple fix, but you’ll need to call a technician to adjust or replace it. Leaks in your ductwork means that cold, unconditioned air from inside your attic gets sucked into your ductwork. What Can I Do If My Heater Is Blowing Cold Air? Have your system professionally cleaned to take care of this problem. If you notice your furnace only blows cold air on occasion but your home is still maintaining its temperature than this may be simply a setting on your thermostat. However, the fan will keep running, cooling the furnace to protect it from potential damage. A flame sensor that’s covered with grime or worn out can cause the burner to keep shutting off. If your furnace continues to blow cold air then you should check if you have a two-stage furnace. This can cause the air to … Your furnace may be blowing cold air because the filter is too dirty. All Rights Reserved. If you have a gas furnace, a lack of fuel will cause the pilot light to go out. Clogged air filters could be causing cold air to blow out of your vents. 2. © 2021 Patrick Riley, LLC. This is sometimes easily solved by resetting the system. Here’s another possible DIY fix for your heater blowing cold air. 13 Common Causes. Source. Two thermostat issues that could cause your furnace to blow cold air include: Yeah, we know the first one seems like a pretty silly problem but you’d be surprised by how many residents in Phoenix leave their thermostat set to COOL year round and just forget about their HEAT button altogether. Do you have thermostat wars going on in your office? First – make it worse. Is the Pilot Light lit? If the furnace burner itself is neglected, accumulated dust and grime can cause trouble igniting. But, if the switch is bad, they’ll need to replace it. If your furnace overheats, it could end up blowing cold air. Your gas supply could be turned off. If your furnace is blowing cold air, or is not operating at all, a component called the fan limit switch may have malfunctioned. Naturally, all heaters use a fan to blow air, but if your fan setting is set to ‘on’ throughout the day, it explains why the heater seems like it has malfunctioned. If the filter becomes clogged, the unit can start to overheat and cause the burner to shut down. You also don’t want to risk frozen pipes. Translation: When your fan limit switch is set correctly and is working properly, you should never feel chilly air coming from your vents. 3. When a heating cycle begins and your air handler turns on, that cool air will blow out of your registers before warm air does. It’s a chilly problem that no one should have to deal with during winter in the Atlanta area! 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. If your thermostat is set to "on" instead of "auto," it could be causing your furnace to blow cold air. Have you changed your air filter lately? Even worse, the furnace is blowing cold air! 2. See our response to recent issues regarding COVID-19. Well, if your furnace is blowing cold air, it’s most likely due to one of these problems: Your thermostat settings need to be adjusted; You have leaky air ducts; Your fan limit switch settings need to be adjusted; Your furnace is overheating; Yeah, that’s a lot of possibilities. 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. If the leaks aren’t excessive, a professional may opt to repair single leaks. Try changing the air filter and restarting the furnace. 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. Have an expert inspect your ducts along with the furnace. 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. So, once a heating cycle ends and the furnace burners cut off, the fan continues to blow. If your furnace seems to be blowing cold air, it could be a problem with the ignition system. We’ll send over a Phoenix professional to get your furnace back to normal operation. Try turning the furnace off via the power switch. Do this: Turn off your furnace at the thermostat, and check the furnace … IAQ and Mold in NYC Buildings: Are Kids at Risk. 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. And remember: Routine furnace maintenance is the best way to avoid a costly emergency HVAC repair. 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. Again using Occam’s Razor, we can assume that the next likely culprit for your heater blowing cold air is your thermostat. Incorrect thermostat setting. So, how do you know which problem is causing your furnace to blow cool air? Other thermostat issues. Luckily, it’s usually very easy to fix, and problems can also be prevented with … Many of the causes of furnace problems can be prevented with regularly-scheduled cleaning and maintenance. And when this happens, your fan limit switch (the switch we discussed above) will shut off the burners and keep the fan on until the heat exchanger cools down. Now let’s talk about an even more common reason a furnace might blow cold air: you’re using the wrong fan settings. If you have a newer furnace with an electronic control panel, you may need to reset the system. And when the blower slows down, it can’t push as much cool air over the heat exchanger, eventually causing it to overheat. Producing heat through your air ducts error message on your thermostat, air filter routinely, down..., things can go wrong that cause this unpleasant surprise cleaned in a professional may opt to repair leaks... 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