Heaters prove to be very essential devices during the winter season because they ensure your stay warm, cozy, and healthy. If well-serviced and maintained, these unique devices will function smoothly throughout the cold months without any notable problems. However, even with regular heater maintenance service and repair, it is inevitable that your heating unit will always develop some problems. And one of the most common heater problems you will likely experience is your heater failing to blow hot air. When you are faced with such type of problem, it is always to contact your local heater service provider to examine, diagnose, and repair it immediately.

Numerous potential problems might make your heater not to blow hot air. So, today in this particular post, we are going to discuss some of the reasons why your heater may fail to blow hot air.

1. Dirty air filter:

As a result of regular use, your heater’s air filters may become dirty, potentially causing the heater not to blow hot air. If you were not aware, dirty air filters usually restrict the free circulation of air in your heating and cooling system. This, in turn, will reduce the ability of the furnace to effectively distribute warm air throughout your home. It is also worth to note that there are some furnaces equipped with built-in auto-shutoff functionality that springs into action when the filter becomes dirty or clogged, to ensure the burner doesn’t become overheated. And when this occurs, your heater will start blowing cold air. Thankfully, filters are very affordable furnace components that are equally easy to change. So, if your heater’s filters are dirty, it is high time you contact your local heater repair technician to come and change them.

2. Condensate line problems:

You already know that the condensate is another vital furnace component that requires regular maintenance. During the hot weather, the condensing unit constantly functions, dripping some water in a drip pan. This water is directed out of your home through piping where it finally drains off. However, these drainage lines usually get clogged with grime and dirt, particularly if you don’t always maintain your heater regularly. And once they are clogged, your heater’s float switch will eventually trip, making your furnace to shut off. So, if you want to avoid this type of problem, it is very important that you keep your condensate lines clean and unclogged all the time.

3. Pilot light problems:

If you are using a gas-powered heater, you may have noticed that it has a pilot light. Just like any other type of furnace component, the pilot light can get blown out too. And if your heater is fairly older, the chances are high that it will encounter this problem. You’ll need to call your local heater technician to examine your heater to ascertain if this is what is causing the heater not to blow hot air.

4. You might be having a wrong sized heater:

If you have a heater that doesn’t meet your home’s heating and cooling demands, inevitably, you’ll always experience cold air problem. Heaters too small can’t heat your home effectively. On the other hand, furnaces too big will occasionally cycle on and off. This is why is very important that before you buy and install a heating unit, you should consult your local heater installation professional to help you get the right-sized heater that suits your home’s heating demands. And if your current heater is the wrong size, you should seriously consider purchasing a new one.

5. Have a look at the flame sensor:

Dirty or old flame sensors can also make your heater to blow cold air. When your heater’s sensor is covered with dirt and grime, your heater will shut off more regularly. However, the fan may keep working, causing the cold air to blow as a result. Regular maintenance is key to preventing this particular problem from occurring.

6. Examine your thermostat:

If your heater is blowing cold air instead of warm, your thermostat could be the culprit. Have a look at the thermostat and make sure it’s set to heat instead of cool. Also, if the thermostat has a setting, make sure it is set to auto but not on. If it is on the 'on’ mode, the blower fan will run constantly even when the furnace is not heating the indoor air to the set temp setting. And if your thermostat runs on batteries, replace them if necessary. Bearing in mind that a dirty thermostat can potentially malfunction, you should occasionally open the thermostat panel and blow out any debris or dirt that might have collected inside.

These are some of the common reasons that might cause your heater not to blow warm air. As mentioned earlier, it's always recommended to do regular heater service to ensure it doesn’t develop any problem, especially during the cold season.