Why Does My Furnace Blow Cold Air?

Thousands of home central air systems have worked all summer at full throttle to condition cool, refreshing air for California homes. Now, with summer drawing to a close, it’s time to raise the temperature on the thermostat to make our homes warm. To be best prepared for the upcoming cold months, it’s a good idea to run a maintenance check to clean and recalibrate your central air system. You might find that your home’s central air system is among those that simply will not provide any warm air. Though this is a problem at first sight, there can be several reasons as to why and practical solutions to restore proper heating.

The Control Board Has Broken Communication

Natural gas furnaces are complex units with a complicated system of parts within it.  When you find your furnace blowing cold air, the problem may lie within the control board.

A control board is the center of communication within the central air system. It is the method by which communication signals are sent out to its corresponding parts that allow the furnace to function the way it does. If any part of the control board is off, whether through age or damage, it fails to properly signal parts of the furnace to turn on or off.

If this is the case, there may be no other underlying issues in relation to fire source or system technology.

The Furnace Parts Have Worn Down

There are parts within the furnace specifically for heating purposes. The gas valves regulate gas flow and the pilot light is the initial source for live flame. To ensure safe practice, there are safety switches and limit switches in place and these switches work to prevent gas-related accidents.

With any unit, simple aging can contribute to decreased efficiency and performance. Gas valves can wear down and simply won’t work anymore.  Without the gas valves in proper function, there is no gas coming in to feed the flame. This means that though the central air system is running and air is distributed, it is not conditioned to the desired temperature resulting in ambient or cool air.

Safety Switches Have Been Tripped

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Though this is less common, it is possible that your central air system has been shut down by safety or limit switches.

Safety switches shut down the system in the event of a flame roll-out.  A flame roll-out is easy to recognize because parts of your furnace will be scorched with heat, leaving behind visible evidence. This occurs when live flame rolls in and out of the heat exchanger instead of staying inside of it.  Because live flame is uncontained, the safety switch locks down the system in order to prevent contamination or spreading the fire.  If you experience flame roll-out, call your preferred HVAC technician. He has been trained to properly and safely handle fire-related heating problems.

Similarly, the limit switch is responsible for monitoring heat levels within the central air system. If it detects that the system is overheated, the limit switch is tripped and the central air system shuts down to cool. This may be a sign of an underlying issue and also requires the special attention of your HVAC technician.

Heat Pumps Work Differently

Heat pumps split systems and natural gas furnaces are different. While the latter uses gas and a live flame, heat pumps do not require any sort of gas but provide heating and cooling through the refrigeration process and electrical energy.

If you have a heat pumps system and find that it isn’t providing any heating, the problem usually lies within the condensing unit outside or a component within the air handler.

Components of the Condenser Unit Are Out

The condenser unit is a system of electrical panels, fuses and run capacitors that help regulate the refrigeration process that makes heating and cooling air possible. Because it works consistently and many components are needed on an everyday basis, these parts can damage or wear with use and age.  When the condenser is disabled, heating and air conditioning can no longer take place.

It is common that  run capacitors, battery-like pieces, won’t work because of overuse or decreased efficiency. Another reason why the condenser is disabled is because the disconnect fuse has blown.  A disconnect fuse is a mini electrical panel that requires exactly 120 volts of electricity each. Any more or less and the system cannot run.

Heat Pumps Have Reached a Balance Point

Because heat pumps lack the natural gas component of natural gas furnaces, they operate differently. When heat pumps have reached a “balance point”, they must dip into a secondary heat source to warm air.

Heat pumps draw warmth from outdoor air and use it to heat indoor air. Even in colder weather, it is possible to extract heat from the air. However, in extreme weather conditions, natural heat sources may be inadequate and a balance point has been reached. In these cases, most heat pumps systems have been fitted with electric heat strips that provide a secondary source of heat, but if your heat pumps system does not, sufficient heating will not be provided.

Perfect Heating with Service Champions

Service Champions technicians are certified experts who have helped thousands of Southern California families with perfecting their heating and air conditioning. Renown for exceptional customer service and expert technical care, your experience with us is supported with a 100 percent satisfaction guarantee.

Any problem with your home heating has a solution with Service Champions. As technicians, we train for 150 hours each year in our own state-of-the-art training facility. This allows us to handle and service your central air system with the most advanced and efficient methods available.

All members pass drug tests and background checks. For your added convenience, we call to confirm your appointment beforehand and send an e-mail containing the photo IDs of your technicians.

If you would like to experience the difference in air quality with Service Champions, contact one of our friendly representatives in our call center and schedule an appointment at a time most convenient for you.