Why Is My Furnace Blowing Cold Air? | Furnace Repair NJ

Why Is My Furnace Blowing Cold Air? Our NJ Furnace Repair Team Explains

When your furnace is blowing cold air, it can impact your entire home and everyone inside. You’ll need to bundle up and take extra measures to stay warm when you experience furnace issues. And you can’t afford to waste time finding a solution.

Fortunately, our experienced team has spent many decades completing furnace repair work throughout New Jersey. Within this new post, we’re exploring the reasons why your furnace might be blowing cold air and how you can respond to this common problem.

• The Thermostat Fan is Set to “On”

One of the most common reasons your furnace is blowing cold air is that you’re using the wrong setting on the system. You can often resolve these user-error-related problems without expert assistance but make sure you fully understand any changes you’re making before you decide to correct the problem alone.

You may find that the fan of the thermostat is on. When you set a fan to the on position, it means it’s constantly blowing and, at some point, will blow cold air. The blowing of cold air occurs when the ambient temperature reaches a set level.

The thermostat determines when the temperature reaches that level, and then the furnace takes a break until the temperature dips again. Cold air will blow during the furnace downtime. When you set your fan to auto rather than on, the fan coordinates with the furnace, and therefore only hot air will blow throughout the system.

• Someone is Changing the Thermostat 

It could also be that someone else in the space is changing the temperature on the thermostat without your knowledge.

Temperature changes often occur within an office space, where multiple people work, with each requiring different temperature settings throughout the day. If you notice someone has set it to a different temperature, it could also mean that the fan is now on, which may lower the air temperature coming from the furnace.

• Low Thermostat Battery

Another concern is a low thermostat battery. While some thermostats work with your home’s central power structures, others are battery dependent. A thermostat with a low battery may have reduced capacity to control the temperature of the air running through the furnace.

Check the batteries in your thermostat before you speak with an expert. You may find that the problem can be simple to fix, thereby saving yourself thousands of dollars on furnace repair in your New Jersey home.

• Mistakes During Thermostat Installation

Improper thermostat installation may cause issues with cool air blowing through your furnace. Installation problems are increasingly common as more homeowners than ever before are now using programmable thermostats within their homes. Often, the thermostat is not compatible with your home heating system. In this instance, you’ll need to speak with a furnace specialist to determine whether the problem is related to compatibility or relates to a mistake within the installation process.

• Filter Problems

The filter within your furnace is also one of the more common problem areas. And this can be a simple fix depending on the extent of the problem. You may find that a dirty filter clogs the system and restricts the airflow to your HVAC unit. 

This blockage could prevent the furnace from distributing warm air throughout the home. 

Fortunately, most furnaces feature a shut-off, so they stop running when the system detects a blockage in the filter. When this happens, the furnace blows cold air to prevent an overheated burner. However, older systems don’t have this shut-off feature and will continue trying to push through the air despite the blockage, resulting in limited airflow and high costs. 

You will know it’s time to replace your furnace filters when the filter is a brown color. Its shape might also become distorted with use. After replacing the filter, restart your furnace and then wait a few moments for the cold air already in your ducts to blow out. If the issue was related to your filters, you should find that warm air begins blowing through your system within five minutes of the restart. 

• A High-Temperature Switch Limit

If you’ve tried to alter the thermostat or replace the filter without any change in the temperature of the air blowing through your unit, it’s time to analyze more complex problems.

One of the potential causes is a high-temperature switch limit. In a system where the filter is not maintained effectively, other components within the furnace begin to break down over time. And this can lead to the system overheating, which it might try to mitigate by turning on the fan to cool down. 

You might not be aware of this issue until the system starts blowing cold air, and the problem has already caused damage to one of the internal components. Some furnaces have multiple limit switches that check for the temperature at different parts of the equipment. These switches are critical to the regular cycling of the furnace. If they experience a technical error, you should speak with your NJ furnace repair expert at the earliest convenience to have the problem analyzed. 

• Issues with the Condensate Line

The condensate line within your HVAC system requires effective maintenance throughout the year to safeguard your unit. Without this commitment to upkeep, you could find that the system becomes plugged with dirt and grime.

When operating effectively, your condensate line will transport water into the drip pan, which connects to a piping system that takes the wastewater outside. Once the system becomes plugged with dirt, the float switch within the system will be tripped, which then causes the entire unit to shut down. 

If you examine your unit and can’t find any particular cause for the cold air blowing through the system, ensure your local repair team analyzes the condensate line. The experts have special tools they can use to clear out the slime and grime within the unit.

• Gas Valve Problems

As with the condensate line, dirt can accumulate in your gas valve, causing it to shut down. This dirt could be the reason for cold air coming from your furnace. Make sure a local expert checks the gas valve for debris.

• Pilot Light Has Gone Out

If the gas company has completed work in the area recently, their work could have blown the pilot light out. You may then experience a loss of power to the system, which will require you to turn the light back on to regain warm airflow from your furnace.

• Outside Air in the Home

It could be that there are air leaks within the ducts that carry air throughout the home. The ductwork may allow cool air from outside to enter the property through your duct system and cause the temperature to dip significantly. Your local furnace expert can analyze your ductwork to check for leaks and ensure proper airflow.

• Problems with the Burner

The burner within the furnace is also vulnerable to the impact of dirt and grime. When the burner is clogged, very little fuel will get to the area, which leads to the system simply sending cold air into the home. You can try to clean the area yourself to remove the dirt, but it’s often more cost-effective and less time-consuming to call a professional who has the requisite cleaning tools to maintain the burner.

• Issues with the Flame Sensor

The flame sensor will shut the burner off if it’s not operational. This issue could be related to dirt and dust within the sensor. However, because the fan is on a separate circuit, the fan will continue running and blow cool air into the home. A maintenance expert can help to analyze the sensor and determine whether dirt has caused the sensor issue or there’s a technical problem. 

• Problems at the Furnace Fuel Source

The fuel within the furnace might be one of the more direct causes of long-standing temperature control issues. 

For example, you might discover that there’s not enough oil in your oil-powered furnace. Or that the gas valve isn’t fully open within your gas-supplied system. Electrical units can experience a shut-off at the breaker. Each of these issues could be simple to fix. So, make sure you check on the fuel/power source before committing to a more expensive resolution. 

Turn to Air Temp for Furnace Repair in New Jersey

Our team at Air Temp can help you analyze and resolve issues with cold air blowing through your property’s furnace.

We offer a full range of furnace repair and installation services, and we’re available around the clock to help provide guidance.

To discover more about our services, or speak with a member of our repair team, call now.