Your Furnace is Blowing Cold Air: Three Possible Reasons
When the Ft. Smith nights get cold, you expect a working furnace, but what happens if all it blows is cold air? Knowing what causes a gas heating system to blow cold air is tough. It takes a great HVAC technician to find and repair the cause.
Side Note: You should never attempt to repair one of the problems mentioned below on your own. Your repair company will have the experience to do it safely and properly.
That said, you can check two things before calling your local heating repair company. First, if your heater is coming on for the first time since last winter, give it some time. The warm air will take a little while to replace the cold air that has been sitting in the vents.
If nothing happens, check your thermostat. The fan should be set to auto. If it is set to on, the fan will blow cold air when the heater is not on. Bearing in mind these two simple fixes, the three main reasons a heating system blows cold air are a pilot light that has gone out, a dirty flame detector, or an overheated furnace.
The pilot light went out.
The first thing your professional technician is going to check is the pilot light. If the furnace’s pilot light has gone out, and it is not an electronic emission pilot light, the technician will attempt to relight it. The instructions for lighting the pilot light will likely be on the furnace, but it is recommended d to allow a technician to do the job as it may require contact with electrical currents and flammable gas.
The first thing the professional will do is check another gas-powered appliance to ensure the gas is on.
If it is, he’ll move on to the next step. If not, there may be an outage with the gas company or your gas valve may have been inadvertently shut off. The next step is to remove the access panel off the furnace. This will provide entrance to the area where the pilot light is housed.
Getting down to the level of the pilot light, he will light it with a wooden match. He would never use a paper match, since these are too short; it would burn his fingers. If the pilot light does not relight after several attempts, there is another problem and the HVAC technician will move on to checking the flame detector.
The flame detector is dirty.
If the furnace makes two or three attempts of heating your home, then shuts off only to restart and try again, your problem is likely a dirty flame detector. This is not uncommon for heating systems that have not had regular maintenance for the last few years.
As this often requires high voltage and flammable gas, it is highly recommended that you never attempt to remove and clean the flame detector on your own.
So what exactly is a flame detector? Also called a flame sensor, a flame detector is a safety feature within your furnace.
It is constructed out of metal that will make an electrical current only if there is a flame present. It is intended to shut the furnace down when there is not enough fuel for all components of the furnace. Without enough fuel, a burner within the furnace could be burning unsafely. When no flame is detected, the flame sensor shuts the gas valve.
Your technician will attempt to light the pilot light two to three times, since false positives are not uncommon. Then, he will check the sensor for rust and dirt buildup. It is important to note here that with gas fuel comes water, which can rust the metals on the detector.
That is why the technician will look for rust buildup. If he finds any rust or dirt, removal of the detector is the next step. The professional will remove the sensor and clean it by scraping off any dirt or rust before returning it to its proper place. In the less likely event that the technician cannot clean the sensor because it is too rusted, he will get a replacement and insert that in the old one’s place.
The furnace is overheated.
Every furnace has motors that are necessary to the running of the heater. These motors can undergo stress which will lead to them overworking and eventually shutting down. Some of the causes of overheating systems are:
• Blocked air filter
• Blocked air vents
• Short cycling
There are also more complex reasons for a heating system to overheat. Your technician will go over each of these and determine what is causing the overheating. Hopefully, he will be able to fix the problem without replacing the furnace, but there is always the off chance that the furnace is simply too old or is a poorly made unit and needs replacement
It is very important that the system is warming your home properly, which is why it is essential that you call your HVAC company if there are any problems. This article has listed three of the most common reasons a furnace will stop working, but other reasons exist.
The experience and knowledge of a certified technician in Ft. Smith will create the right combination to help him find the challenge and repair it.
If your Ft. Smith, AR furnace is blowing cold air, contact Mountain Air Cooling & Heating at (479) 782-4328 .