Why is my furnace not blowing warm air?

Furnace overheating can be the cause of your cold air dilemma. Changing the dirty air filter can solve this problem. The dirty air filter blocks the airflow, causing the furnace to run longer to heat your home until it overheats. It is important to note that constant overheating can damage your heat exchanger.

Why is my furnace not holding temperature?

Filter – The most common cause of furnace problems is a dirty filter. If you furnace filter is clogged, the airflow will be restricted. Thermostat – If your thermostat isn’t properly functioning, your furnace won’t respond in the correct manner. First and foremost, check to be sure it is set to “heat”.

Is it normal for furnace to blow cold air?

Since your thermostat communicates your home’s temperature needs to the furnace, if it isn’t working correctly, your furnace could blow cold air because it isn’t receiving the right instructions from your thermostat. Replacing your thermostat ensures accurate communication with your furnace to stop cold air issues.

Why is my furnace blowing hot air but not cold air?

But if you’ve set your fan to be “on” at all times, it’ll blow cold air during the furnace downtime. Therefore, set your fan to “auto” to coordinate it with the furnace and you’ll just have hot air blowing, not cold. Somebody else is adjusting the thermostat .

How can you tell if your furnace is hot or cold?

You wake up in the morning, or come home from work, and you can instantly tell something is wrong. The house is cold. You can hear the furnace running, and you can even feel air coming out of the registers. But it’s not hot air coming out, it’s cold! Well, it’s not COLD cold, it’s just room temperature.

Why is the air coming out of my furnace lukewarm?

Air ducts are leaking. The lukewarm air coming out of your furnace can also be the result of leaky air ducts. If your ducts are leaking (and ENERGY STAR says that almost all homes leak about 30% of the air in their ducts), cold outside air is making its way into your ductwork.

What to do if your furnace won’t turn on?

Go to your furnace and watch it when it turns on. If the burners ignite and heat, the problem isn’t the gas supply. But it could also be a thermocouple or flame sensor problem (see below). The fix: Make sure the gas valve to your home is turned on. You may need to call in a professional if there’s a gas issue inside the furnace itself.

Why is my HVAC not blowing hot air?

Simply put, a clogged air filter can cause your furnace to overheat, shut itself off and give you the illusion of a furnace not blowing air when, in fact, it is your air filter that is causing your furnace to turn itself off as a safety precaution.

What to do when your furnace is blowing cold air?

What to Do If Your Furnace is Blowing Cold Air. Check the thermostat: If the fan is set to “On” it will continue to blow air even when the furnace is not on. That could be the reason for the cold air you are experiencing. Set the thermostat to “Auto”, turn on the furnace and observe what happens. Also check the battery on your digital thermostat.

Why is my furnace blowing only cold air?

If it’s not the filters or the thermostat, then a faulty gas valve could be the main reason why your furnace is blowing cold air. The dirt and debris that have amassed might be restricting the valve to operate as it should.

Why does furnace blow only warm air?

Most commonly, a dirty furnace air filter. The dirty air filter will block airflow, causing the furnace to run longer to heat your home until it overheats. Solution: Change the air filter and see if your furnace starts only blowing warm air. DON’T ignore this problem.