Your furnace is supposed to heat your home, so the last thing you’d expect is to feel cold air coming from your home’s air registers when your system is running. It could even be running in the air conditioning mode due to a malfunction. Again this is when the heat is on. Reasons Your Furnace is Blowing Cold Air. I changed two conditions. Re: Air Through Vents even while ac/heat off Nov 19 2012, 6:24pm When the HVAC is off, the outside air pushes its way through the vents, that's also why sometimes you will notice on the lower speeds, that the air moves quicker when you are driving 70 mph vs stopped. The colder the outside temperature gets the more air we have dropping from the vents. We have 4 zones but normally leave one zone off. It blows cold air when the heat is on. The A/C is blowing cold air and is working fine. This post will explain what causes cold air to come out of the vents when you have your heater on, when warm air should be coming out … As a result, any air that blows out of the vents while your heater is off will usually feel cold. This is when the furnace is NOT running. Most often this air will feel cold when the fan is “on” but if you don’t notice a change in your overall home’s temperature most likely this is just blowing out room temperature air. ... because it gets automatically deducted. (Sometimes this happens for 30-60 minutes.) My husband and I have a propane furnace. As nuts as it may sound, the air in your home can feel chilly even though the heat pump may be working completely fine. One common HVAC mishap is when your heater turns on, but the air coming out of the vents is still cold, so what should you do about that? Report Save. I have a combination AC/furnace system in my home. This might sound crazy, but a heat pump can be working just fine even if the air feels cold. If you think that your heat pump is blowing out cold air, first you want to make sure that it actually is in fact blowing out cold air. I noticed today that only 1 of the thermostats showed cool ON … Hello, My furnace blows code air from vents when heat is off. Cost for electric nowadays is out of this world. As soon as I stop at a red light, or am idling for any length of time the air coming out of the vents begins to lose temperature until it blows cool air. Items in red usually require a service call. When we start our van the vents blow consistent cold air when the adjustment is for heat no matter how long we "warm it up". Furnaces are one of … 2 of the returns blows cold air out of the return vents but not out of the supply registers. 5 Reasons Cold Air Comes Out of Your Vents When You Turn On the Heat We build a house 1 year ago and when the temperature gets below 50 degrees outside we start getting cold air coming through 4 vents of our house. So if you feel the air blowing out of the vents while the furnace is off, the air will seem cool since it’ll be at about room temperature. ), so the temperature actuators generally fail first. All I have to do to get hot air again is give it a little gas, say 200 more rpms, and the heater immediately responds with warmer air, hot air if I maintain 1000 rpms. Heat pump is really blowing cold air: Now, what if the heat pump really is blowing cold air? Furnace Basics. New heat pump owners often notice that the air coming out of the vents isn’t as warm as when they had a gas furnace. 1. share. If you’ve got cold air blowing out of your vents when the heat is on, check out this guide, and follow the steps to diagnose, and potentially fix the problem. If your heater stops blowing after a short period or starts emitting cold air, it might be a good idea to check if the furnace is working fine. Sometimes we can rev the engine up which will, for some reason, get the heat coming out, but usually it takes driving it for a while before any heat will come out. Let’s look at some common issues that would cause your furnace to blow cold air. Our Lennox system is doing the same thing now for several months. My thermostat is off, but there is air blowing from my vents. Why is cold draft air coming out of the vents? The cold air return lets in cold air when the furnace is off. I have a 2010 Nissan Armada that is not blowing hot air when the heat is set on 90. My car is 2011 Chevy Impala. To protect the heater from malfunctioning altogether, engineers embed automatic limit switches that are responsible for turning the heat-generating furnace off. Don't know brand or if it is a heatpump - think it may be since it is one unit supplying AC and heat. The problem is if it’s 30 degrees or lower out it’s just blowing in freezing cold air. Have an expert inspect your ducts along with the furnace. Check that the fan blower switch is … If your furnace starts blowing warm but then quickly turns cold, the flame sensor may need attention. First, shut your heater and fan to the off position on your thermostat, because if your vents are blowing hot air, continuing to run your heater will only continue the problem. Some of the reasons your furnace might blow cold or feel like there isn’t as much warm air coming from the vents include: An improper thermostat setting. If you’re looking for some winter furnace maintenance, check out our post on the subject. Lately, cold air comes out from our vents, which are on the floor. What could it be? A dirty air filter restricts airflow into your furnace. $85 for the last month when we haven't had heat or air on one single day seems high? First, I opened the heat vent wider - This seemed to stop cold air return from blowing cold air when the furnace is off. When one or more of these components fails, the heat or cold air … What is this and how can I stop this from occuring? Meanwhile, the outside air is redirected back into the outside environment as a blast of icy cold air. Below is a list of possible causes. Just purchased a condo in AZ. But as it turns out, this is a furnace problem that comes up often in many Bay Area Aside from the vents blowing out the dash at the driver and passenger, on the cars with the faulty calibration of the radiant heat sensor, you will also get cold air out the defrost vents and the floor vents. The neat trick with heat pumps is that in summer, this process is easily reversed, allowing the same mechanism to instead transfer heat out of your home, cooling it in the process. I fixed it for a homeowner in that subdivision, and they told their neighbors, and … Drivers changed air temperature far more often than they change the mode (defrost, floor heat, dash vents, etc. It’s normal – If you’re only getting a bit of cold air when your furnace first kicks on, but the air is nice and warm after a few minutes, it’s likely fine. Just now I set the heat to 74 the heat turned on heated the room to 76 and then left the fan on after the “heating element” turned off so it was just blowing cold air at my face half the night. Then heat starts to appear fine. The Chevy Silverado climate control system uses several different components that come together to either cool down or heat up the cabin. That prevents your heat pump from blowing cold air out of the vents. i.e. Chevrolet Silverado 1999-2006: Why Do My Vents Blow Only Hot or Cold Air? I don't know why. If your car heater is suddenly blowing out cold air instead of heat in the middle of a bitterly cold winter, you have a good reason to be frustrated. No heat to feet or defrost. It must push out the cold air from the vents before the warm air … Your furnace blowing cold air could be caused by hot air escaping through holes in the duct work that carries the heat throughout your building. In other words, it's not putting out any heat at all. I picked up a whole housing subdivision of customers because the installation contractor did not hook this up properly. I have noticed that when my heating is off in the winter, I can feel cold draft air coming from the vents in my home. 11. Last week, at one point, I turned AC on and cold air was blowing out of return instead of sucking and no air was coming out of supply's. We bought the home in 2004 and the previous owner updated the furnace from electric to propane. Quickly shut thermostat off and then on again and problem was solved. Maybe your heater is not blowing hot air even though the fan is running. Let us explain… The air could be warm but still feel cool. 3,770. In a dual zone system, you wind up with a blows cold one side, hot on other side condition. Several issues could be going on with your home’s heat. So you will feel air blowing through your vents but the air is not heated or cooled by your furnace system. Think of it like turning on a hot water tap. Change the air filter. Nest Thermostat Generation 3 2 years ago. William Reed on February 18, 2017: Hi my name is william and i have a 2005 dodge magnum. 5 Reasons Why Your Furnace Might Start Blowing Cold Air. JustinRandy131. It blows cold air for the first 10 minutes of each heating cycle. Unreliable car heaters can make the cold winter months practically unbearable. When room temp falls below 70, heat kicks off and blows hot air through vents and everything is as expected but when temp reaches above 70, it starts blowing cold air even when settings are set to "Heat" and FAN it set to "Auto". However, if you force the air out the vents only, using the 'mode' control, it will blow warm out those vents, if the system is working correctly. Compromised flame sensor. When that happens, the HVAC system can be stuck on blows cold air or blows hot air. Home inspection noted no problems with AC unit. ... Nissan Rogue 2016 heating problem I noticed in my car today that my air vents are only blowing room temperature air. My thermostat is off, but there is air blowing from my vents. This is plenty warm to heat your home to your desired 72°F. Heater working but only blows out front vents. All vents are on the opposite side of the house than the furnace. When my heat is on warm/hot air is coming out of the passenger vents - as it should; but the air coming out of the vents on the drivers side is cold. Heater blows out cold air. My heat is blowing out cold air from the vents - Answered by a verified HVAC Technician We use cookies to give you the best possible experience on our website. Restricted airflow can overheat your furnace, causing a safety control to shut off the burners. Car issues can make people scratch their heads. Been to Nissan twice. Why a Heat Pump Will Blow Cold Air. In fact, when you stand in front of it, cold air rushes out of it as it it were connected directly to the outside of the house. I set desired temp to 70. The nest seems to blow warm air normally but once it switches to alternative heat source, then it starts blowing cold air. Well this could be caused by several things. level 2. The same effect happens with your furnace. Heat pumps usually produce air that is 85-92°F. The air coming out of your vents might seem rather cool or your home is not staying as warm as the temperature you set. I really hate the propane, but it is what it is. Before replacing Heater Control Unit, it would only blow hot air from front vents- With this replacement it will now change from cold to hot and the air flow pressure does change from the front vents when changing the setting dial but there is still no air at all to feet and defrost. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them. Heat pumps typically produce air that is about 90-100°F, whereas furnaces can produce air as high as 120-125°F. The same vents that provide my AC in the summer also provide heating in the winter. This issue could be caused by an improper thermostat setting. 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