What Can Go Wrong With a Clogged Furnace Filter

Close up of furnace filter at an angle

There is plenty of info about furnaces we’d like our customers to know, but this single fact can make an enormous difference in how often someone needs to call for heating repair in Andover, MA and how much they pay each winter for heating. It can even prevent a furnace from needing an early replacement. In this post, we’ll go over what can go wrong with a furnace due to a filter that’s become clogged because it hasn’t received a regular change.

The Filter Isn’t an Air Cleaning Product

Before going farther, we want to make sure you know the difference between the furnace filter and an indoor air quality filter. The filter in place on the furnace cabinet isn’t there to help clean the air. Its job is to prevent debris coming in through the return air ducts from entering the furnace cabinet. People often forget about the filter because they think its only purpose is to clean the air—and that’s not what it’s for at all. (If you want air cleaning filters, we can specially install those for you.)

The Troubles of a Clogged Filter

If a filter isn’t changed and is allowed to become totally congested with dust, lint, and other debris, it can cause the following negative effects:

  • Lower efficiency: A clogged filter makes the blower fan work harder to draw air through the filter and into the furnace. This makes the furnace more expensive to operate.
  • Reduced airflow: With the restrictions placed on airflow through the filter, the level of airflow will start to drop around the ventilation system, resulting in a decline in comfort in some rooms.
  • Overheating: More heat will be trapped inside the furnace because of the clogged filter, and this will cause the limit switch to shut off the furnace early to prevent overheating. This also leads to a furnace that short-cycles, which puts more stress on the system.
  • Tripped circuit breakers: The higher strain placed on the blower fan may cause the motor to trip the circuit breaker, causing the entire furnace to shut down.
  • More repairs: Extra strain creates a higher chance of repairs. Also, the clogged filter will distort, allowing dust, dirt, and lint to slip around the sides and into the cabinet, where it can create damage.
  • Shorted system life: The combination of many of the above factors will contribute to the furnace wearing down faster than normal. Without regular filter changes, the furnace may need to be replaced years early.

Changing the Filter Is Simple

It’s not tough to change the furnace’s filter: just slide it from the slot on the furnace and put in a new one. New filters are inexpensive and can be purchased in packs from most home improvement stores. The stronger the filter, the less often it will need to be changed—but please don’t let a filter go longer than 3 months without checking up on it.

Basnett Plumbing, Heating & AC has served MetroWest Boston since 1987. Fix your furnace with our professional help.

Need HVAC Service?

Contact the experts at Basnett Plumbing, Heating, AC & Electrical.
Call us at 978-431-2906!