What does it mean if a furnace is blowing cold air?
If a thermostat is set incorrectly , you might notice your furnace blowing cold air from the heat registers, a lower than expected temperature reading on the thermostat, or you may even hear your air conditioner running outside. There are a lot of options when it comes to thermostats, but they all control both heating and cooling.
Is it normal for my furnace to blow cold air?
It’s normal for cool air to emerge from the vents at first because the furnace has to warm up. Think of it in the same way as turning on a hot water faucet; you’re going to get cold water at first. The same effect happens with your furnace. It must push out the cold air from the vents before the warm air can come.
Why does my electric furnace sometimes blow cold air?
Why Is My Furnace Blowing Cold Air?
- Your thermostat settings need to be adjusted. Yeah, we know the first one seems like a pretty silly problem but you’d be surprised by how many residents in Phoenix leave ...
- You have leaky air ducts. Ductwork with a loose connection. ...
- You have a problem with your fan limit switch. ...
- Your furnace is overheating. ...
- Still getting cold air from your furnace? ...
Why does the home gas furnace blow cold air?
- The burners will not burn any gas (no ignition and combustion of gas).
- If there is no combustion of the gas then, then the furnace won’t produce any heat.
- When there is no heat produced, the furnace can continue blowing cold air only. ...
- A dirty flame sensor will also cause your furnace to make short heating cycles.
How do you fix a furnace that blows cold air?
How To Troubleshoot Furnace Blowing Cold AirStep 1: Check Thermostat Setting. First and most importantly, make sure your thermostat is set to Heating Mode. ... Step 2: Evaluate and Adjust Your Vents: ... Step 3: Assess Furnace Filters and Replace Filters If They Are Dirty. ... Step 4: Call An HVAC Pro.
Why is my furnace running but no heat?
Dirty filters are the most common cause of furnace problems. Dust and dirt restrict airflow—and if the filter gets too clogged, the heat exchanger will overheat and shut off too quickly, and your house won't warm up. If the blower is running but no heat is coming out, replace the filter.
What are signs that your furnace is going out?
Heating Up: 7 Signs That Your Furnace Needs RepairsAbnormal Furnace Smells. Furnaces can smell like the fuel that they use, especially when they turn on for the first time in a year. ... Difficulty Starting the Unit. ... Discolored Pilot Light. ... Inadequate Heat. ... Persistent Noises. ... Poor Air Quality. ... Tripped Carbon-Monoxide Detector.
What to check if heat is not working?
Heater Not Working? 7 Troubleshooting Tips:Check that your thermostat is set to “heat.” ... Change the filter. ... Make sure the gas is on. ... Clear the chimney exhaust flue. ... Clean away leaves and debris from exhaust vents. ... Flush out the drain lines. ... Check for blocked ducts restricting airflow.
Where is the reset button on a furnace?
All furnaces are equipped with a reset button. They are generally red or yellow and are located inside the blower compartment. The reset button is a safety feature that will shut down the furnace when a problem is detected, often a hot or overheating furnace, before it trips the circuit breaker.
What is the average lifespan of a home furnace?
15 to 20 yearsTHE AVERAGE FURNACE LIFESPAN A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.
When should I be concerned about my furnace?
Sudden and unusual furnace noises when the equipment starts, runs, or shuts down are cause for concern. These are the main sounds you need to beware of: Grinding or scraping. Rumbling.
How much does a new furnace cost?
We found that the range of total costs for mid-efficiency or high-efficiency furnaces is generally near $1,700–$9,700 and includes the estimated installation rates.
Why is my heat not kicking on?
If your furnace is not turning on you should first check if the filter is clean. Dirty filters cause insufficient airflow and can prevent the furnace from starting. Other reasons it won't start can stem from improper thermostat settings, forgetting to turn on the gas line, or faulty pilot light.
Why is my heat not coming through the vents?
Four common reasons there isn't enough hot air blowing out of your vents are: A Vent is Blocked. The Air Filter is Clogged. Leaky Ductwork.
Why is my furnace not responding to thermostat?
When a furnace is not responding to a thermostat, there is either a problem with the heating unit or the actual thermostat. Lack of power to the thermostat, wrong settings, and outdated software might be to blame, as well as faulty wiring, a tripped breaker, and a dirty furnace filter.
Why is my house not warming up?
The reasons your house is cold even with the heat on could be because of poor insulation, your furnace not working properly, rooms with high ceilings, or your heating system doesn't cover the whole house. Each of these issues can prevent your home from properly heating.
Why does my furnace shut off?
For furnaces without pilot lights, flame sensors (also known as flame rods or flame detectors) are used to ensure proper heat. If the flame rod is covered in dirt or grime, it can cause the burner to shut off. As a result, the heater will start blowing cold air, or it may quickly cycle between warm and cold.
How to fix a furnace that is not heating?
First, make sure that the thermostat is set to “heat,” and that the setpoint is at a high enough temperature to turn on the furnace. Next, check the thermostat to see if it is set to “on” or “auto.” If it is set to “on,” the furnace blower will continue to run regardless of whether it is actually heating the air. Switching the thermostat to “auto” will ensure that the fan only blows when the furnace is providing heat.
Why does my pilot light go out?
If the light continues to go out after following the steps and you’re sure there’s no draft blowing it out, a faulty thermocouple may be to blame. Most homeowners prefer to call in a furnace technician to assess and replace this part.
How much does it cost to replace a furnace?
A home without heat is not only uncomfortable, but it can be dangerous as well. However, with the cost of a new furnace ranging between $2,614 and $6,310, most homeowners won’t want to replace a furnace until it’s completely necessary.
How long does it take for a furnace to warm up?
If the furnace kicks on and immediately sends out cold air, give it a minute or two. Heaters need a bit of time to warm up, as it must push out cold air from the vents before sending out hot air. A similar effect occurs when turning on the hot water in the shower—cold water always comes out first. If minutes pass, the heat’s not turning on, and the air is still cool, continue troubleshooting.
Can a furnace leak out of the attic?
It is also possible that the furnace itself is functioning as it should, but there is damage to the ductwork that carries the heat throughout the home. If there are holes and cracks in the ductwork, cold air from the attic could enter the air ducts, while warm air could leak out by the time it reaches the vents. Ductwork damage may also rear its head in the summer months, resulting in inefficient home cooling. The best way to fix this issue is to seal the ducts as soon as possible.
Why does my furnace keep blowing cold air?
If your furnace overheats, it could end up blowing cold air. In such cases, a safety control device known as the limit switch will shut off the burners. However, the fan will keep running, cooling the furnace to protect it from potential damage. Overheating will almost always occur due to restricted airflow, and this is often caused by ...
Why does my heater feel cold?
Maybe your heater is not blowing hot air even though the fan is running. As a result, any air that blows out of the vents while your heater is off will usually feel cold.
Why does my furnace overheat?
Overheating will almost always occur due to restricted airflow, and this is often caused by a dirty air filter. Restricting airflow into the furnace means that the unit will run a lot longer and much harder to provide adequate heat, as a result of which it will overheat.
Why is my gas furnace not heating?
Pilot light or ignition problem. If your gas furnace seems incapable of blowing hot air, the problem could be with the ignition system. In such a case, your heater is not lighting the fuel, as a result of which it cannot heat your home. Confirm whether the pilot light is out. If it’s out, try the following:
Why is my heater not working?
Major duct issues. If you have large holes and leaks in your air ducts, cold air from your crawlspace or attic might get into the ducts. As a result, it might seem like your heater is not working. A good solution for this is Aeroseal Duct Sealing.
Why does my furnace lock down?
Your furnace might lock down for safety reasons if it is not getting the amount of gas it requires to provide warm air. If your gas supply is not turned off, then you probably have a severed line, in which case you’ll need professional help.
Why do furnaces have condensate drains?
Newer, high-efficiency furnaces feature condensate drain lines for removing the water created during the heating process. Clogged drain lines will almost always activate a switch that is designed to prevent the burners from lighting.
How the Furnace Blows Warm Air
Before we get to the common reasons for blowing cold air, perhaps it would help you understand how the furnace generates warm air in the first place and why cold air coming out of the supply vents is an anomaly.
Reasons Why the Furnace Blows Cold Air Sometimes
The furnace can blow cold air occasionally for various reasons, ranging from air leaks to short cycling and everything in between. The following are the seven most common causes and how to fix them.
Summary
Now you know why your furnace blows cold air sometimes. Again, we strongly recommend professional intervention whenever you don’t feel too confident in your DIY abilities.
Why does my furnace blow cold air?
One of the most common causes of a furnace blowing cold air is not actually a repair at all. 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. The fan setting on your thermostat has two options, “on” and “auto”.
Why does my furnace vent get cold?
Sometimes ducts may be leaky causing air from cold places like your basement and attic to get into your vents. This can contribute to cooled air in vents and inevitably cause cool air to pass through your heating system.
Why does my furnace overheat?
As filters become more clogged a few things happen. First your filters ability to keep your air clean is reduced causing more contaminants to flow through your air. Next, it actually restricts air flow that causes your furnace to work harder and if left too long…funny enough… it can actually cause your furnace to overheat. ...
Why does my furnace fan turn on?
First, the furnace fan turns on automatically when your home’s thermostat detects that the house is a different temperature than what has been set. This causes your furnace to kick in and start heating up while the fan circulates the air .
What is a condensate drain?
New high efficiency furnaces have what is known as a condensate drain. It’s job is to remove water that is created during the heating process. This amongst most features in a furnace have sensors that will turn off certain features.
What is a pilot light on a furnace?
It is essentially a small flame that is running at all times and is required to light your furnace burners.
What does "on" mean on a furnace?
The “on” option is exactly how it sounds. Your Furnace Fan will be running all the time even when the furnace system is off. So you will feel air blowing through your vents but the air is not heated or cooled by your furnace system.
Why is my furnace not blowing cold air?
One simple reason why a furnace is not blowing cold air is that your furnace filters are ‘dirty’ or clogged. This may sound quite innocent but clogged furnace filters can lead to even more serious problems than a furnace not blowing hot air.
How does cold air come out of furnace ducts?
Air needs to go through a furnace filter to enter the heating chamber. After it’s heated up, it also has to pass a furnace filter in the ducts. If filters are clogged, not enough air enters the heating chamber, and you won’t have a lot of hot air. The amount of how air is further reduces when the blower pushes it out. The net result can be cold air coming from the furnace ducts.
Why do gas furnaces use condensation lines?
Here’s why this happens: High-efficiency gas furnaces create condensate (water, if you will) when functioning properly. This water has to be emptied and that’s why all condensate gas furnaces use a condensation line. It’s a specialized PVC pipe that drains the condensate continuously.
Why won't my furnace start?
Without a functioning gas pilot light, your furnace will not start heating. Without the heating, the blower will just blow out cold air. You need to check if your gas pilot light has gone out. To check it, just locate the pilot and see if it won’t light or if it won’t stay lit. If this is the case, the cold air coming from a furnace is due to a faulty pilot light.
What is the purpose of a furnace flame sensor?
Every furnace has a furnace flame sensor. The function of this sensor is to instruct the burner if you need more or less heat. This is a finely tuned device that needs to function properly.
How to make a furnace blower not run when it's hot?
Solution: Set the fan setting to “Auto”. This mode only runs the blower when the furnace is actually generating heat. That means that only when air is hot, the furnace blower will blow it inside your home.
What does "on" mean on a furnace?
Well, “On” setting means that the furnace blower will be running continuously (24/7). That means it will run when you’re actually running the furnace (in this case you will get hot air) and when the furnace is not running (in this case you will get cold air).
