House Heater Blowing Cold Air [6 Easy Solutions]

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If your heater is blowing cold air, this is a sign of an issue of refrigerant, air filters, thermostat, registers, ductwork or outdoor condenser unit. The good part is that most of these issues can easily be solved by yourself but for others, you may need to call a professional to come and take a look. In this article we have outlined the reasons for your house heater not blowing cold air and the solutions to each of them. 

Before we go into details lets us first briefly look at how your heat pump works to better understand why it is not working properly.

heater thermostat

How Does a Heat Pump Work? 

Heat pumps are one of the most  energy efficient heating systems to warm your house. They use electricity to transfer heat from the cooler outdoor air to the warmer indoor air just like the refrigerators or air conditioners work. Heat pumps are so effective that they deliver 3 times more heat energy to your home than they consume.  

They work by transferring heat rather than generating it making them, an efficient way to warm your home. In winter time they provide you with warmth and in summer time they cool your space. 

 Read also: House heater not blowing hot air

5 Reasons For Your House Heater Blowing Cold Air 

1)Thermostat Settings

Make sure you check the set temperature on the thermostat even if you are sure, you set it correctly. It is always a good idea to idea to double check the thermostat settings especially with the smart thermostat, you could have accidently touched setting on a smartphone app. 

 Besides that, Peoples indoor temperature comfort can vary and so folks that live with you may have adjusted the thermostat in an attempt to bring down temperature or in an attempt to save money. If thermostat setting is Ok, then move on to the next step. 

If your heater is blowing cold air, make sure your thermostat is not set to “on” but to “auto”. When the thermostat is set to on, it will continue blowing cool air even when is it not in the heat cycle. But if it is on “Auto” and still blowing cold air, then check if the batteries are weak and need a replacement. Sometimes batteries can affect how a thermostat work. 

2) Clogged Air Filters 

Major heating problems are caused by small issues. A dirty or clogged air filter will restrict the flow of air into the heating system and reduces the efficiency of the heating system. Less air will be heated and distributed into your home. 

 Clogged air filters prevent air from going through and the air can by-pass the filters. When this happens, that unfiltered air can deposit dirt on the coils and affect their heat-absorbing capacity. And so, the system will not transfer enough warm air into your home. It is in order to change or clean filters often when you have pets a dust environment.  

You can clean or swap them once every two months. 

3)Ductwork Leaks 

If there are leaks in the duck works, then hot air won’t be distributed around your home properly. A compromised ventilation system will create heating problems. In Addition to that, if there isn’t proper insulation in the attic or walls, rooms can feel colder than they should. 

Sometimes rodents are to blame. Once they have their way into the attic, they can create leaks and damage to the ductwork. This can lead to loss of heat through leaks and rooms do not feel warm as they should. Because of that, your heating system will overwork to try and keep rooms warm. 

Sealing the ducts should allow warm air to reach the vents more effectively 

4) Blocked Registers 

When the registers are blocked or clogged, the heating system can’t take it in enough air, so it does not distribute enough air in your home. Make sure you check condition of the registers, if they are dirty or clogged clean them and see if the problem is resolved.  

If only one or just a few rooms feel colder than the rest, then there could be something obstructing the vents, or they could have been accidently closed. Check that the vents are not closed 

5.) Dirty Condenser Coils 

Your heat pump’s outdoor unit can accumulate dirty and debris outside including leaves and soil. The parts that can become covered in debris are the evaporator coil and the condenser coil. The dirt will in the end insulate the coils and reduce air flow around them. This will prevent the coils from absorbing the heat from the outdoor air to transfer into your home. So, your heater will blow cold air. 

If the outdoor environment is dusty, it can quickly make the coils and fins dirty. Luckily you are able to see and tell if your condenser unit is dirty. 

6)Regular maintenance 

In order for your Heat pump to work properly, it needs regular and consistent maintenance. Air filters need cleaning or replacement often. Other components of your HVAC system also need to be checked and examined from time to time. 

If you hear strange noises or smell something unusual do not ignore. These small issues are the ones that cause unforeseen break downs. 

It is a good idea to have your HVAC maintenance tune -twice a year as recommended. But for air filters, clean them or replace them more often although manufacturers say they are good up to 3 months of use. 

Maintenace reduces the risk of unexpected break downs and also costly HVAC repairs. 


When winter comes, it is that time that you expect to make use of your heater. But the problem of your house heater blowing cold air can make your home feel unbearably cold. The things you need to rule out before calling an expert include; 

  • Thermostat 
  • Air filters 
  • Duct work 
  • Condenser coils 
  • Maintenance  

If you are not comfortable or not too sure about what to do then calling HVAC repair services is smart. 

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