Common Culprits in Furnace Breakdowns

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With the winter season comes many common culprits in furnace breakdowns. With many delicate snow falls, a myriad of outdoor activities for the children and adults and of course the coziness of snuggling up indoors, one cannot forget the importance of your furnace heating your home . But sometimes, we encounter an obstacle with our furnace, that is not allowing it to work optimally or even at all.  Keeping in mind that HVAC equipment is mechanical and although you may have been diligent in having it maintained and serviced, things can sometimes go astray.

Here are some of the common culprits that can be the source of your furnace not providing sufficient or any heat in your home:

Culprits in Furnace Breakdowns #1 – DIRTY FILTERS:

Dirty Furnace Filter Thermal Concepts

It is the easiest and first thing that any homeowner can address themselves.  Check to make sure the filters are clean.  When filters are not regularly replaced, they clog up and this causes the furnace to overwork.  If this goes on for too long, other parts of the furnace get strained and more complex issues occur.

Culprits in Furnace Breakdowns #2 – FLAME SENSOR:


This is an important safety element on your furnace.  If the flame sensor is excessively dirty, it will lose its ability to correctly assess the temperature of the inside of the furnace.  Its main job is to test for increased heat.  If it senses heat, the gas will be allowed to continue to flow.  If it doesn’t, it will shut down.  It is common for flame sensors to be dirty as there is often a buildup of soot and other combustion by-products.  The flame sensor is something that is taken care of at regular maintenance/inspections.  Sometimes they can fail because they are meant to sense electricity from the flame that the furnace produces.


circuit BOARDS

The circuit board is the central hub of your furnace.  It helps to diagnose furnace problems.  It helps to protect your safety and it controls the function of the furnace such as the electronic ignition, opening of gas valves, checking the flame sensor, activating the blower motor, shutting off gas and venting the heat exchanger during each heating cycle. 


A blower motor turns the blower fan, sending air through your air ducts and into each room of the home.  A dirty motor can cause the bearings to wear and eventually stop working. Regular maintenance is key to making sure you don’t have to replace this component too early.

Culprits in Furnace Breakdowns #5 – HEAT EXCHANGER:

The Heat Exchanger is an essential part of the heating process.  It is a thin metal shield that separates the combustion chamber and the blower motor.  The heat exchanger takes the heat energy from the combustion chamber and transfers it into air that is safe to breathe. This is made of metal which expands and contracts (as it heats and then cools).  As time goes on, the repetition of the expansion and contraction can cause the metal to bend or crack.  The heat exchanger must be air-tight, otherwise, the gases produced in the chamber can escape and be hazardous or even dangerous to your health .i.e carbon monoxide.

These are only a few of the most common culprits of furnace breakdowns.  Many of these can be avoided with regular maintenance, but keep in mind that aging components or systems plays a big role too in breakdowns and replacement of parts.

Our recommendation, just as you do with your vehicles, is to get regular maintenance and inspections.  Schedule a yearly appointment so that you can avoid being left out in the cold.

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At Thermal Concepts Ltd. we offer a Piece of Mind Maintenance Program.  Once you sign up, we contact you to schedule a time that is convenient for you.  Leave the thinking to us!

Contact us today to learn more!

151 Applewood Cres # 18
Vaughan, ON, Canada

(416) 410-3450