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Quick Answer: Why Is My Furnace Blowing Cold Air Instead Of Heat

A clogged filter is one of the leading reasons for a heater blowing cold air. But even if you swap the air filter with a brand new one, dirt and debris can still be found within the unit. This could eventually lead to overheating. If your furnace looks pretty dirty, call an HVAC provider for a professional clean.

What do I do if my heater is blowing cold air?

How To Troubleshoot Furnace Blowing Cold Air Step 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.

How do you reset a furnace that blows cold air?

When a furnace blows cold air, there may be an issue with the unit’s electronic control panel. This is sometimes easily solved by resetting the system. Turn off power to the furnace at its ON/OFF switch. Wait a few minutes, then flip the switch to ON.

Why is cold air coming out of my vents when heat is off?

This issue could be caused by an improper thermostat setting. Check that the fan blower switch is set to “auto” and not “on.” When the “auto” setting is chosen, the fan will only run during a heating cycle and won’t push air that feels cooler through the vents in between cycles.

Should I turn my furnace off if its blowing cold air?

When a furnace only blows cold air, there’s a chance the heater could have overheated. But don’t worry, this usually doesn’t mean the unit is broken. When the system overheats, there’s a safety feature that shuts the system off. This is a good thing—it could prevent a fire, carbon monoxide leak, or even an explosion.

Where is the reset button on a furnace?

Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.

Why is no air coming out of my vents?

The most common cause of low air flow through the vents in your home is blocked or dirty AC filters. When you clean or change your AC filters, be sure to vacuum the metal grates closing the filters in at the same time. Another way to prevent common home cooling problems is to clean your AC registers on a regular basis.

What would cause a furnace not to kick on?

The Pilot Light (Faulty Ignition Sensor) The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite. This is typically the problem if you can hear your furnace click on but it does not fire up. If the sensor or ignitor is dirty, it will need to be cleaned.

Should air be coming out of return vent?

If cold air is seeping into your ductwork, it must blow out of the duct registers before the furnace’s warm air can—thus it feels like air-conditioned air is ventilated through your home despite the thermostat being set to heat at 72-degrees.

How do I stop cold air coming through my vents?

How to Keep Cold Air Out of Your Vents Install insulation. Poor insulation causes rapid cooling of the air as it moves through your home. Check connections. Over time, the connections in your ductwork can come loose. Update your HVAC. Older HVAC systems are less efficient and require more upkeep than modern models.

Should you cover cold air returns in winter?

Because hot air rises and cold air falls, you need to adjust your return vents with the seasons. In the summer, your lower vents should be closed and your upper vents should be open. In the winter, your upper vents should be closed and your lower vents should be open.

How long does it take for a furnace to heat up?

In general, your furnace will take about an hour to warm up your home by a few degrees. Although this depends on a home’s size and the furnace’s age, you should expect the temperature to feel slightly warmer after about 30-45 minutes.

Do all furnace blower motors have a reset button?

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.

How many times can I hit the reset button on my furnace?

Don’t hit “reset” more than twice. The process pumps oil into the burner chamber, where it can accumulate if you have no ignition. Then when the furnace finally does start, it can do so explosively. So if the button won’t reset, or quickly pops up again, it’s time to call a professional repair service.

How do I know if my cold air return is working?

Try this simple test when your HVAC system is running: get a piece of tissue paper and dangle it about six inches from one of the return vents. You should be able to see it being gently pulled towards the vent. Next, place it up against return vent and see if the air suction holds it in place.