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Furnace Pressure Switches: What You Need to Know

Did you know that over 65 percent of carbon monoxide poisoning cases occur in the home? This can happen due to a variety of reasons, including your furnace.

Furnace pressure switches are a failsafe that's implemented to help keep your home safe. However, when your furnace pressure switch malfunctions, it may not be able to do its job.

Keep reading to learn more about the role of the furnace pressure switch and why proper maintenance is important.

a harmony heating technician working on the inside of a furnace to show the pressure switch

What Is a Furnace Pressure Switch?

A furnace pressure switch is an essential component of your heating system that is crucial in ensuring safe and efficient operation. Its primary function is to monitor the air pressure within the furnace and ensure it's at the correct level before allowing the ignition sequence to begin.

When you turn on your furnace, the blower fan creates airflow through the combustion chamber. The pressure switch senses this airflow and determines whether it's sufficient for proper combustion. If there are any issues with low or no airflow, such as a blocked vent or dirty air filter, the pressure switch will prevent the burner from igniting.

The Role of a Furnace Pressure Switch

This safety mechanism is vital because inadequate airflow can result in incomplete combustion, leading to dangerous carbon monoxide buildup or a potential fire hazard.

The pressure switch helps protect your home and family from these risks. It does this by preventing ignition when there isn't enough airflow.

In addition to its safety function, a furnace pressure switch also aids in energy efficiency. It ensures that only clean and properly heated air flows throughout your ductwork, maximizing comfort while minimizing wasted energy. Without this control device, your heating system could operate inefficiently by producing excessive heat or distributing unfiltered air.

Common Problems with Furnace Pressure Switches

Like any other component, these switches can experience issues that can disrupt the functioning of your furnace.

Some common problems you may encounter include the following:

  • A stuck or ruptured diaphragm

  • Electrical failure

  • Draft inducer motor failure

  • Constricted combustion air vent

  • A restricted intake air vent

  • Leaks around the assemblies

  • Condensate drainage blocked

  • Flue obstructions

However, proper maintenance can help catch problems early and prevent issues before requiring furnace repairs.

How Do You Know If Your Furnace Pressure Switch Is Bad?

If you notice any of the following issues, it could be an indication that your furnace pressure switch is malfunctioning:

  • Frequent cycling

  • Failure to ignite

  • Error codes or blinking lights

  • Continuously running blower motor

  • Audible clicking noise

There may be instances where you're tempted to bypass or disable the pressure switch to fix an immediate problem. While this might seem like a quick solution, it is not recommended and can pose significant risks.

While common signs may indicate a faulty pressure switch, it's always best to consult a professional HVAC technician from Harmony Heating and Air Conditioning for an accurate diagnosis. A trained expert will have the knowledge and experience to thoroughly inspect and test the pressure switch to determine if it needs replacing.

Contact Your Local Furnace Technician in Calgary

Furnace pressure switches are an integral part of your HVAC system. They help keep your home and family safe.

Harmony Heating & Air Conditioning is here to help ensure your system stays safe. Contact us today to get a free quote for your furnace repairs, maintenance or replacement today!


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