Why is my Furnace Blowing Cold Air?

Is your furnace blowing cold air, making it really windy and uncomfortable inside the house? If your furnace is doing the exact opposite of what it should be doing you have come to the right place for solutions. 

For folks that do not know why you need a furnace in your homes, a furnace is used in cold countries for heating up your home through the circulation of hot air. 

There might be several reasons as to why your furnace may be blowing out cold air. There are several methods that could help you fix the problem. 

Pay close attention to this blog as this might help you troubleshoot the problem yourself without even dialing the helpline number.

Is your AC blowing hot air? Find out why here.

Why is my Furnace Blowing Cold Air?

If your furnace is blowing cold air, there might be something wrong with its fan or the thermostat must be defective. In this case, the furnace needs immediate attention from an expert.

What are the Troubleshooting Tactics That you can Use?

When looking for a solution, you need to make sure that you understand the problem correctly and then choose the correct solution.

Below are some troubleshooting tactics that will fix the heating issue in your household real soon.

1. Thermostat’s Fan Setting

Some thermostats allow the blowing of hot air as well as cold air. In this case, there is a possibility that your thermostat’s fan mode might be on.

The fan setting ensures the control of the blower and if it is kept on the blower will run non-stop. It also means that even if the furnace heats up it won’t be giving out hot air but will give you cold air instead.

 To fix this problem make sure to keep your thermostat’s fan mode on auto. This will make sure that your furnace will only operate when the furnace is heating up.

2. Furnace’s Air Filter

There are instances where furnaces blow out cold air instead of hot air when the air filter is too dirty.

Dust, dirt, and debris block the airflow inside the furnace’s heat exchange,r this, in turn, causes it to overheat. A lot of thermostats have a high limit switch which gets triggered when the thermostat is overheating.

This is installed to make sure that the furnace burners shut off to prevent the heat exchanger from cracking.

To fix this problem you will have to check your furnace’s air filter. It is mostly located next to the blower. If it is dirty, you will have to change it.

There is a possibility that you might have to contact a technician to assist you in resetting your furnace.

3. Pilot Light

In older thermostats, pilot lights signify whether a thermostat is heating up or not.

Therefore, if a pilot light isn’t working the furnace burner won’t heat up and thus no heat will be released. To fix this problem try the following steps:-

  1. Turn your furnace off. You can do this by turning your thermostat heat off.

2. Locate the furnace’s reset switch and pilot light assembly. The assembly, as well as switch, should be located in the bottom section of the furnace. Once you open the furnace’s cover you will notice a knob containing three settings.

    a.) Pilot



3. Wait 3-5 minutes after turning the knob to “off”.This will prevent the entry of gas from coming through the pilot.

4. Press down the knob after turning the knob to “pilot”. This will enable the re-starting the flow of gas to the pilot.

5. Hold the lighter to the pilot opening until the flame lights as you press the knob. Make sure that when the flame lights that it is a steady blue cone that is hitting the middle of the thermocouple.

6. Try turning the knob to “on”. At this point, your furnace should start working fine.

7. Try to turn the furnace on at the thermostat. Before turning the thermostat back to heat, make sure that the temperature is set 5 degrees below room temperature. Once you do this, you should be receiving hot air.

In case your pilot light still won’t light up or stay lit, try calling a furnace technician. There is a possibility that your thermostat is experiencing a thermocouple malfunctioning.

There might be other issues that could cause your pilot light to work inefficiently.

4. Condensate Line

In high-efficiency furnaces pooling of water around the furnace indicates that the furnace’s condensate line (usually a PVC pipe) may be clogged or blocked.

This causes the furnace to shut down or not work efficiently. This happens because when a high-efficiency furnace runs it creates condensates that empty out into the drain line.

An overflow backs up the water and this causes the line to get blocked this triggers the overflow kill switch which shuts down the furnace to prevent further furnace damage caused due to excessive water flow.

Dust, dirt, mold, and ice are some of the common causes of condensate blockage. A broken condensate pump might also encourage or cause condensate overflow. 

In such cases, you will have to contact a technician or professional to fix the pump. In case ice is the reason for condensate blocking, try wrapping the condensate line with heat tape and pipe insulation.

How to Tell for Sure if There Really is a Problem?

You can try using an infrared (IR) thermometer to measure the temperature of the air coming out of the vents.

If you do not own an infrared (IR) thermometer simply observe your thermostat. The temperature should gradually rise according to your given setting.

As long as the above-mentioned methods prove that your thermostat is working fine you will have no reason to be worried.

In case your problems are still not solved you will have to call up a professional or a technician for help.

It might sound strange but a thermostat might be working efficiently even if the air coming out feels slightly cold. There might be a problem with the settings of your thermostat in this case.

You might have to contact a professional heating company to diagnose your thermostat-related problems if technicians or professionals are unable to resolve the issue. With the rapid digitalization in progress finding help isn’t that much of a problem.

Most companies have an online page or their contact info can be found online along with customer reviews. Just choose a company that suits your needs and consider giving them a call.

Bottom Line

In this blog, we have covered everything you need to know about your furnace, its problems, and what might cause your furnace to blow cold air. Hope this can help you solve your furnace problems! 

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I have always been a shopaholic. A lot of times my questions went unanswered when it came to retail questions, so I started Talk Radio News. - Caitlyn Johnson

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