Why is my heater blowing cold air instead of warm air?
Has this ever happened to you? The room’s just a little too cold, and you turn on the heater or furnace only to be greeted with cold air instead of warm. In addition to being annoying, it could mean there’s an issue with the furnace.
Let’s look at the most common causes of cold air coming out of a furnace, how to fix them, and when it’s time to call a professional.
Your Thermostat Settings Might Be the Culprit
Thermostat settings are one of the main culprits of cold air coming from a furnace, and they aren’t always the obvious ones. Maybe it’s set to “air” instead of “heat”, it could be set too low, maybe it has seasonal or hourly settings designed to conserve energy, or perhaps a stuck “hold” setting is keeping the temperature low.
Check all thermostats in your house to make sure there aren’t any issues with the settings. If everything looks good, it may need to be calibrated or serviced by a Furnace or Heater services professional.
Your Furnace Might Need a Little Warm-Up Time
Some furnaces, especially older models, might need a few minutes to get going. In most units, the fans will start blowing out air immediately, but if the actual heating isn’t taking place, the air might be cold at the outset.
What you can do: Start the furnace as normal and check it in about 10 minutes. If the air is still cold, keep troubleshooting.
Dirty Air Filters Are Restricting Airflow
Another thing to check is the air filter, usually located on the side or back of your heater. If it’s covered in dust or has been used for too long, the airflow can become restricted.
Restricted airflow means the device has to work harder to pump out warm air, which can lead to problems in other parts of the heater. Some devices also have safety mechanisms that lower the heat or turn the unit off if it’s pumping out too much warm air.
Quick fix: Check the air filter for visible signs of dirt and replace it if necessary.
Your Pilot Light or Ignition System May Have Gone Out
Many older systems use a pilot light, a small flame that ignites the burners. Newer models might have a flameless design that works in the same way. If the light or ignition system is out, the burners can’t ignite, and no warm air will be produced.
Safety tip: Turn off the gas supply before relighting the pilot! If there’s too much gas floating around, it can cause a massive explosion.
The Flame Sensor Could Be Dirty
The flame sensor is an essential safety device installed in every furnace that shuts the unit down if no flame is detected, preventing gas leaks and carbon monoxide from entering your home.
However, if the flame sensor is dirty, it might not be able to “see” the flame, causing it to turn off the furnace. It’s a relatively simple repair if you’re comfortable opening the unit panel. If not, consider calling a heater maintenance services company.
There Could Be a Problem with the Ductwork
If some rooms in your home are warmer or colder than others, there may be an issue with your ductwork. The air ducts that distribute warm air throughout the house may be blocked or improperly installed. A professional heating expert can usually diagnose the problem pretty quickly.
Your Furnace Could Be Overheating
Another safety mechanism your furnace is likely to have is a sensor that detects overheating forcibly shuts down the unit to prevent damage. An overheated furnace can also lead to inefficient heating and higher energy bills.
Likely causes: It can be caused by dirty filters, dirt buildup inside the unit, or a malfunctioning part. Unplug the unit and after it cools down, replace the filter, clean the inside, and fire it up again.
The System Might Be Too Large or Too Small for Your Home
Some furnaces are better for smaller homes and others are designed to work best in larger homes. The owner’s manual or the manufacturer’s website should have information on its output levels and for what size home they’re best suited.
Solution: You will most likely need to buy a new furnace for your home, but first check with the heater services professionals to make sure the new system is the right for you.
Electrical or Gas Supply Issues
As most furnaces are heated by electricity or gas, it stands to reason that a lack of electricity or gas could result in not enough heat being generated.
What you can do: Check the gas supply valve or, for electrical units, check the breaker. These issues can be very dangerous, so it’s best to call a professional heating maintenance provider.
It Might Just Be Time for an Upgrade
Sometimes it might be a combination of issues causing your furnace to blow cold air, especially if it’s an older unit that’s experienced heavy use. A replacement could be a little expensive, but the peace of mind and comfort it provides are well worth the price.
Warm Air, Warm Heart — Let’s Get Your Heat Back
If you need heating repair in Melbourne, Florida or the surrounding areas, call Melbourne One Hour Plumbing and Heating – We’re on time or you don’t pay a dime! Instead of waiting around for the other heating services companies to show up “when they can”, our expert heater repair technicians show up when we say we’ll show up, guaranteed.
Don’t sit in a cold house hoping your furnace will fix itself. Call Melbourne One Hour Plumbing and Heating to get your house back to the comfort levels you need. Don’t delay, call us today!