1. Why is Your Furnace Blowing Cold Air?

    All gas, oil, and electric furnaces are sensitive and calibrated pieces of equipment. It only takes one or more components to be out-of-whack, or not tended to that creates problems. One of the more vexing and mysterious problems the Chicago HVAC specialists at Aircor see is when your furnace is blowing cold air when the heat is on. Or it could be the opposite: you feel cold air coming from vents when the heat is off.

    Whether you own a gas, electric, or oil furnace blowing cold air, troubleshooting why your furnace is blowing cold air instead of heat is where you should begin before resorting to calling in an HVAC contractor. Below we give some basic troubleshooting steps to help you figure out why your heater is blowing cold air in the house.

    Thermostat Setting

    At the top of the troubleshooting list is to first check your thermostat. If you notice the thermostat is set to ON, it is most certainly the problem. What’s occurring is your heater blower continues to operate, although your home has reached its maximum comfort level. The solution? Reset the thermostat to AUTO. Now the furnace will automatically shut off the blower once your home has been thoroughly warmed, and come back on when it needs to raise the temperature again.

    Overheated Furnace

    If your furnace is blowing cold air sometimes, it could be your central heater is overheating. What causes this to occur is the limit switch shut off the furnace blowers. It does this to stop the overheating, reducing the temperature to a non-dangerous level.

    What’s behind an overheated central heater? Most likely, it is a grimy filter. An obstructed filter will limit airflow, motivating your gas, electric, or oil furnace to take more time to heat the living spaces, causing overheating as a result. You can replace the filter and find out if it resolves the issue. If you own an oil furnace, changing the filter is more difficult and a dirty job, so contacting an HVAC pro to do it for you is the better option.

    Since we’ve mentioned oil furnaces, another reason for your oil furnace blowing cold air is the oil tank may be empty. Without fuel to light the burners the oil furnace will be blowing cold air instead of heat.

    Pilot Light Issue

    If your central heater is not blowing hot air in the house an unlit pilot light may be the cause. There are three approaches to dealing with an unlit pilot light:

    1. Try relighting the pilot light. If the flame catches and remains burning, then problem solved!
    2. Pilot light won’t fire up? Check the gas valve switch to see if it is on. If it’s on, inspect the pilot light to see if debris has accumulated and clean it. Cleaning the pilot will permit gas to flow to it.
    3. If the pilot light ignites but goes out again, the thermocouple is at the heart of the matter. Adjustment or replacement needs to happen. You’re mechanically inclined? Go for it. Otherwise get in touch with a heating contractor.

    Condensate Drain Lines

    If you’ve purchased a high-efficiency furnace the condensate drain lines may be plugged up, keeping the burners from initiating.

    Burner Problems

    If your oil or gas furnace burners have built-up dirt it could also prohibit the burners from igniting and the furnace blowing cold air.

    Ductwork Problems

    The ducts of your central heater could be causing the problem of the blower not blowing hot air in the house. Causation might be holes and leaks in the ductwork has allowed warm air to escape and the furnace blowing cold air instead of heat.

  2. What’s the Difference Between High-Efficiency Furnaces and Low-Efficiency Heaters?

    High-efficiency gas furnaces versus regular gas heaters: just what is the difference? Trust the Chicago HVAC team at Aircor—it all comes down to a furnace’s AFUE rating (Annual Fuel Utilization Efficiency). A standard or low-efficiency gas furnace has an AFUE rating of between 80%–85%. In a high-efficiency furnace, the AFUE rating, according to the model ranges between 90%–95%.

    But AFUE ratings don’t paint the whole picture. Because if you buy an 80%-efficiency furnace that doesn’t mean you won’t get a well-engineered and reliable furnace. You will. And it can give good service for 10 to 20 years. Modern technology has made it possible for low-efficiency furnaces to conserve energy better than the outdated gravity furnaces of the past.

    To talk about today’s high-efficiency gas furnaces you need to know they have changed greatly over the past 10 years. High-efficiency gas heaters can support AFUE ratings as high as 95%. And these programmable models come with many extra features to help conserve energy output.

    To explain further the differences between a low-efficiency gas furnace versus a high-efficiency gas furnace let’s consider four components of both.

    1. Condensing Process. Furnace vent condensation concerns come with regular gas furnaces. These gas furnaces (with an AFUE rating of 80%) exhaust 20% of its heating energy up the furnace’s vent.

    High-efficiency furnaces rated at 90% AFUE or better are known as condensing furnaces. A condensing furnace possesses an integrated extra heat exchanger, whose job is to replenish the 20% lost in a low-efficiency heater. This is accomplished when combustion gases are redirected, condensed, and converted to water, releasing heat, and the heat removed by the extra heat exchanger. The result is the AFUE percentage bumps up, reducing the cost of operation.

    1. Adaptable-Speed ECM Blower. 80%-efficiency furnaces possess common one-speed, on-and-off blowers. When turned on the blowers run at 100% of capacity and eat approximately 500 watts of electrical power. Because of the frequent on-and-off cycles, temperatures fluctuate conspicuously from room to room. The drawback of a one-speed blower is once a home is completely heated, a blower operating at full capacity is not necessary to maintain the comfort level of a home. In other words, electricity is being wasted.

    In contrast, the adaptable ECM (electrical commutated motors) blowers on 90%-efficiency heaters operate almost all of the time, stopping the on-and-off cycling, which produces temperature fluctuations. Because they run at a lower heat volume, they only use approximately 80 watts, a considerable savings in energy.

    1. Multi-Stage Burners. With an 80%-efficiency furnace the burners operate at 100% of capacity. In temperate weather conditions, this high-capacity burner is only useful for the cold season, otherwise it uses up energy needlessly.

    A 90%-efficiency furnace contains multi-stage burners that intuit what temperatures are necessary to maintain the comfort level of a home. As heating requirements lessen, the multi-stage burner automatically switches to a lower, energy-savings level. The benefits include reduced power bills, energy conservation, and cleaner emissions.

    1. Sealed Combustion. A low-efficiency furnace uses the air from inside the home to initiate the burner flame. As a consequence, this lowers the humidity in living spaces and increases winter-air symptoms of itchy skin, irritated throat, and static electricity.

    A more serious issue is the possibility of carbon monoxide being released into the home due to backdrafts. This means combustion gases don’t go up the exhaust vent like they should, but are diverted into living spaces.

    A high-efficiency furnace contains a sealed-off combustion unit that protects the home from fumes. Two pipes work in conjunction to one, route the combusted air outside the home, and two, exhaust the gases. As a result, the home’s humidity level is protected.

  3. When It’s Time for an Air Conditioning Tune-Up


    HVAC air conditioning tune-ups are a necessity to keep your air conditioning humming along. And as a matter of course air conditioner tune-ups should be performed twice a year, particularly in the spring before the hot and humid days of summer arrive.

    If you’ve been lax about scheduling a tune-up for your air conditioner you could be caught unawares in the middle of a heat wave, when your air conditioner has to work its hardest to keep your home cool. If it’s dirty and neglected and straining to cool your home, a breakdown is not surprising.

    Before you find yourself in the middle of an air conditioning crisis, here are some signs you can be aware of when your air conditioner is showing signs of strain, and threatening to break down:

    • If you’ve been operating your air conditioning unit day and night, and not getting relief from the heat, check one of the supply registers by putting your hand above one of them. The chances are the air will feel warm. This is an indicator your air conditioner is undercooling your home, or maybe not cooling it, period. If you find the air is cool enough but the airflow is weak, this means cool air can’t spread throughout your home. Two reasons could be the cause of the problem: a leaky duct or a worn-out filter.
    • Do you find the air conditioning is shutting on and off too often? We’re talking about a span of a few seconds. When this occurs the air conditioner is not able to remove excessive moisture from the air, leaving you with humid and stifling air. The constant turning on and off causes more wear-and-tear on the air conditioner components.
    • Are you feeling too hot in one room and too cold in another? Aside from poor insulation, direct exposure to the sun, or windows that let in too much air, your air conditioner might be the cause.
    • If you discover an outdoor air conditioner part that looks like it is leaking, the cause could be an obstructed or damaged drain tube. Although not considered a grave problem, the longer you delay getting it repaired, the more likely you will develop a mold problem.
    • If you’ve had your air conditioner a number of years you’ve become acquainted with how it should behave. Any deviation from the normal sounds of its operation should be a red flag you need a tune-up sooner rather than later. Typical sounds your air conditioner is malfunctioning are squeaking, shrieking, scraping, or some sound that hasn’t shown up before. Irregular sounds demand you schedule an appointment for an air conditioner tune-up immediately before a serious problem develops.
    • If you are becoming aware of musty odors emanating from your air conditioning, mold is growing in some unknown part of your air conditioner. If you smell sharp or burning odors, the cause might be burnt-out wire insulation. The only way to take care of this problem is to call for an air conditioning tune-up. The HVAC air conditioning repair technician will know how to rid the air conditioner of the odors and repair whatever has caused them.

    If you’re finding yourself needing to dust more frequently, it could be a dirty and undermaintained air conditioning unit is at the root of it. When dirt and dust have been allowed to accumulate on the air conditioning unit parts, the air blower will blow the built-up dust into your air. An HVAC air conditioning repair technician can come out, and do a thorough cleaning of all the air conditioning parts, which will have the air conditioner running like new again.