The popular song goes, “Baby, it’s cold outside.” But what happens when it’s also cold inside? While Florida is not known for its white Christmases, it can still get fairly chill during the winter months. So when you turn on your furnace, you may wonder, “Why is my furnace blowing cold air?” There are several answers to this question, but today, we hope to help you narrow it down with our furnace issues guide!
10 Reasons for Your HVAC Blowing Cold Air in the Winter
Having cold air when you expect heat can be frustrating. Luckily, there are several things you can look for to get your home toasty warm again. Some things you can easily do yourself, and others require a professional hand. Whatever may be the case, here are the top ten most common reasons why cold air is coming out of your furnace.
1. You Just Turned on the Heat
If you just turned on your furnace and notice cold air, don’t panic yet. Just like you have to wait for a little while for an oven to warm up or for your shower to get steamy, your furnace takes a few minutes to heat up. However, since you turned it on, it’ll try blowing out air—even if it’s not warm yet—giving the impression that your furnace may not be working properly. During this time, you may also notice an odd smell from your vents as it heats up. Give it about 15 minutes, and if it’s still blowing cold air, check another item on our list!
2. Old Air Filter
Your air filters are essential for the function of your HVAC, whether you want a cool home or a warm home. If you have an old or dirty air filter when you turn on your furnace, you may feel cold air because the hot air is actually stuck behind the filter. This is something you can replace yourself; however, just make sure the furnace is off, so you don’t get directly hit with hot air.
3. Malfunctioning Pilot Light
If you’ve gone through the first two steps and you still have cold air, the most common issue is often the pilot light. If you have an older furnace or one that runs on gas, your pilot light is what allows your furnace to heat up. However, sometimes, this light will either go out or malfunction. If it just goes out, you can relight it yourself. If it keeps going out, there may be a deeper malfunction that requires a professional to figure out. To check if your pilot light is on, you’ll usually find it at the bottom of your furnace behind a little glass or metal door. If you see a small flame, it’s on, but if there’s nothing there, then the pilot light is off.
4. Low Gas Supply
If you have a gas furnace, cold air may indicate your furnace isn’t getting enough gas flow to generate warm air. This is especially true if you notice the pilot light keeps going off or that it’ll start blowing cold air and then suddenly shut off. Because gas can be such a tricky element to work with, this is something that requires a professional to handle.
5. Ductwork Leak
Ductwork allows all the air in your home to flow evenly to the different rooms. So when there’s a leak in your ducts, you may notice you’re not getting the heat you expected. You may also notice the following signs of a duct leak:
- Higher energy bills
- Certain rooms have heat while others don’t
- Increased dust in your home
A duct leak can quickly become a problem, especially if you have a gas furnace. Without the proper seal, carbon monoxide could get into your home and cause dangerous health effects. This is why we highly recommend you buy a carbon monoxide detector for your home to protect you from this odorless, lethal gas. If you suspect a duct leak, contact a professional to get it fixed as soon as possible.
6. Thermostat Issues
A common issue if you notice cold air from your furnace—especially if it seems to go from hot to cold throughout the day—is that your thermostat is set to “On” instead of “Auto.” “Auto” allows your furnace to stop blowing air as soon as it reaches the desired temperature, but “On” forces the furnace to continue blowing air, even if it’s no longer heated. This is as simple as checking your thermostat and flipping a switch.
7. Overheated Furnace
While it may at first seem counterintuitive, if your furnace is overheated, you may notice cold or no air coming from your vents. This is because modern furnaces have safety checks in place that turn the furnace off when it reaches dangerous temperatures. An overheated furnace can have several causes, such as:
- Your furnace is old.
- Your flame sensor is dirty or damaged.
- Your ducts are clogged.
- The fan blower is blocked or damaged.
If this is the case, the best course of action is to contact an HVAC professional to diagnose the root problem.
8. Clogged Evaporator Coil
Your evaporator coil works by absorbing heat and allowing the refrigerant to evaporate, as its name suggests. With AC, this process helps get rid of excess heat and allows cool air. With a furnace, the coil absorbs the heat and helps distribute it. However, if the coil is clogged, it’s unable to absorb heat well which may cause cool air to blow in your home. A professional should handle this situation to protect your safety and warranty.
9. Clogged Condensate Line
Even during the winter in Florida, it’s still humid. Condensate lines help remove this excess moisture from your home. However, if these lines become clogged, your pilot light might struggle to light, or your furnace may have a safety feature that shuts down the furnace. A professional will be able to determine the source of the issue and get your condensate line unclogged and working again.
10. Blocked Air Vents
Either because you have them closed or something is blocking them, a blocked air vent can cause cool air since the furnace is not getting enough air to warm up. If you see all your vents are open but there’s still cold air, you may want a professional to check for any blockages within your vents.
The Weather May Be Frightful, but The Furnace Is Delightful with Comfort Temp
As the weather cools down, you deserve to enjoy a warm, cozy home. If your furnace is blowing cold air, the technicians at Comfort Temp are here to help. We can identify the issue and provide services to get your furnace up and running again. Enjoy a delightful winter this season with our furnace repair services!
