Lasko Heater Blowing Cold Air [7 Easy Solutions]

There may have several issues in the case of the Lasko heater blowing cold air. Like wrong thermostat settings, blocked air filters, furnace problems, and clogged ductwork.

Also, incorrect fan functions, dirty flame sensors, blown circuits, or broken heater coils are the possible reasons behind this problem. 

lasko heater blowing cold air

Don’t get in trouble. Here, we will discuss active solutions to all the above issues with possible reasons. Just go through our step-by-step suggestions to solve this problem. 

Lasko Heater Blowing Cold Air [7 Easy Solutions]

After a long time using the Lasko heater, you may face many types of problems with it. Blowing cold air from the heater is the most common of them. Dealing heater with such a problem is completely impossible. 

To think about this, we have come here. We are going to solve this problem with some effective and quick working methods. So, let’s start reading the article sensibly.

1. Check Thermostat Settings

If your Lasko heater is blowing cold air instead of warm air, be sure the first problem is in the thermostat. Sometimes the wrong setting of the thermostat, the defective or damaged battery of the thermostat will occur this problem

Also, if there is any loose wiring inside the thermostat, it stops working properly. Whatever the causes, you need effective solutions. Here we have provided all the solutions:


  • First, check the temperature of the thermostat. Always set the temperature higher than your current room temperature. 
  • Verify the dialer of the thermostat is working correctly. You may need to replace the dialer if it is faulty.
  • If there is any loose wiring, tighten it.
  • Now, check the batteries of the thermostat. If it is failed to supply power, it will stop working. Thus, replace the dead batteries quickly. 

2. Clogged Air Filters

After a long period using, the heater’s air filters get clogged with debris and dirt. If your Lasko heater is not blowing warm air or heater shuts off frequently, the problem may start with the blockage of the air filters.

The blocked vent will prevent smooth ventilation. Resolve this issue by following our mentioned methods:


  • First, turn it off and unplug it from the main wall socket to clean the heater.
  • Then start by cleaning the surface of your heater. Remove all the dirt from there. 
  • When done, you have to unscrew the heater and scrutinize it. Clean the interior with a duster and remove the caked dust from there. 
  • Now check if all the filters are working well. You may replace it if needed. 

3. Furnace Overheating Problem

If replacing or cleaning the filters doesn’t work, it would be better to check if the furnace is functioning well. Due to overuse, furnaces become overheated. There is a protection switch in every heater to prevent the overheating problem. 

When the furnace becomes overheated, the protection switch is activated, and the heat-producing furnace is turned off. Thus heater automatically produces cold air. Now, have a look through the solution procedures:


  • First, turn off the heater and unplug it.
  • Leave for about 30 minutes and let the furnace be cold by itself.
  • Then, restart the heater.
  • If the heater again produces cold air, it’s better to contact the manufacturer.

4. Check Ductwork

The heater may produce cold air if there is any problem with your home’s ductwork. When the ductwork is blocked with debris, it interrupts the normal airflow from the heater.

Thus the heater becomes overheated, and the protection switch is enabled. For that, cold air comes out from the heater.

Moreover, if there is any leak or tear in your ducting system, it leads to the same problem. In this case, the heater produced hot air, but it mixed with the cold air of the ductwork. All active solutions for this problem are:


  • Properly clean out the cogged debris from the ducting.
  • Then, fix all the leakages of the ductwork if there have.
  • Assemble the heater and the electric panel in proper venting.
  • If you feel trouble, you must have to contact the manufacturer.

5. Incorrect Fan Functions

You may see a fan function on the menu bar in various Lasko heater models. The engineer embeds this function to use the heater as a fan.

If the fan switch is turned “ON” and the thermostat’s temperature is below your room temperature, cold air may come out from the heater. 


  • Set the heater in “Heat” mode.
  • In the case of the running fan, set the thermostat thermometer higher than the current room temperature. 

6. Dirty Flame Sensors

It would be best to clean out the flame sensors regularly to keep the heater in fluent working flow. The dirty flame sensor will occur producing cold air from the heater. 

Sometimes the flame sensors are filled with residue and carbon dirt and stop normal working. To get rid of this problem, you must go through a proper cleaning process. Here you go like this:


  • Before going through the work, turn off the heater.
  • Then unplug it from the main power supply. Now, it is time to clean the flame sensor. To do this, unscrew the sensor that is attached to the bracket.
  • Clean out all loose dirt from the sensor with a microfiber cloth or spray with an air duster.
  • Then again, reattach all the compartments 
  • Before turning it on, you may clean the grille with a vacuum cleaner brush. Also, properly wipe out the outer side of the heater with a damp cloth. Then, turn on the heater. 

7. Blown Circuit Or broken heater coil

If there is any blown circuit or breakout in the electrical path, the heater will fail to produce warm air. Sometimes broken heater coil will create such problems. No worries. Read our suggested solution sensibly.


  • First, you have to unscrew the heater.
  • Then verify whether there is any broken circuit. If so, fix it or replace it with a new one.
  • Besides, check all the electrical paths. Fix it if there are any breakouts.
  • It is not a bad idea to check the coil as well. If you find any breaks in the coil line, replace them with newer parts.


How do I reset my Lasko heater?

To reset the Lasko heater,

  • Turn the power button off
  • Unplug the heater
  • Leave it for 10-15 minutes
  • Turn it on, and it is reset.

Why does my heater keep shutting off?

The possible reasons for your heater keep shutting off are low airflow, blocked air filters, overheated furnaces, and faulty wiring. 

Final Verdict:

We have tried our best to resolve this critical issue with the Lasko heater. Hopefully, you can solve the problem by following our Lasko heater tech supportive guide.

Still, if you have any questions, don’t hesitate to ask us in the comment section. Thank you for staying with us. 

About William

William is the founder of He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

Leave a Comment