Common Furnace Problems and Their Causes


As a homeowner, paying for maintenance and unexpected repair costs can have a drastic effect on your budget. One expense that can be particularly costly is furnace repair. The national average per call is nearly $300, and in cases where extensive repairs are needed, it can cost nearly $1,000 or more. Some problems are common and may even be preventable in the future. However, it is important to first understand how your heater works, what might cause it to break down, and when you need to call a certified furnace repair company for assistance.

Squeaking or Buzzing While Cycling

If you hear squeaking or buzzing as your heater cycles, you may be facing a worn-out motor belt, a dying fan, or debris being caught in the fan. Debris can be especially harmful to your furnace’s fan, as it can jam there and burn out the motor. While you can examine the fan to ensure it is not coated in dust and is free of twigs or other small bits of debris that can get sucked down through the heating ducts, you might need a professional furnace repairperson to replace worn belts and fans.

Professional Furnace Repairperson
Professional Furnace Repairperson

Reduced Airflow

When your heater suffers from reduced air flow, it may be something you notice gradually. Some rooms may take longer to heat, your furnace may cycle for a longer period of time, and you might hear the fan start and stop more often during a cycle. This is usually caused by clogged and dirty filters, which is a problem that can be easily rectified by changing them.

Once you replace your furnace’s filters, you may want to schedule a maintenance call with your local furnace company to have your unit cleaned professionally. There many benefits to this, especially if you have it performed in the fall before you start using the heater. Your filters may last longer, and you might experience lower heating costs.

Furnace Will Not Light

If your furnace begins its cycle but then the ignition fails to fire and turn on the pilot light, you can be left with a cold unit and, in turn, a cold house. There may be several causes for this issue, which include a faulty ignition switch, a bad flame sensor, or a clogged burner. In most cases, these parts may need to be replaced or professionally cleaned.

If you notice that your furnace lights briefly but then shuts down before the cycle starts, this is usually due to a faulty flame sensor. While they can sometimes be cleaned, the problem may resurface in several months, so you might want to ask a company that specializes in heating repairs about which solution is the best choice for your furnace.

Furnace Repair
Furnace Repair

Fan Runs Constantly

Your furnace’s fan is instrumental in blowing warm air into your home. However, it is designed to shut off when a cycle ends. If you find that your heater’s fan rarely or never shuts off, this could be a potentially simple fix. A blowing fan may mean that your thermostat is set to auto, which causes the fan to operate even when the system is not cycling. If the switch is not in the auto position, then you may be facing a malfunctioning thermostat or a jammed fan relay.

Replacing a fan relay or thermostat is a job for a professional furnace repair company; however, the more you can tell the tech about the problem, the better they might understand the issue. Note any sounds you may hear or, if the fan does shut off, how long it takes for it to start up again. This may also help your tech diagnose the problem quickly.

Common furnace problems can appear costly and troublesome when you first encounter them. However, when you understand how your heating unit functions and which issues are not unusual, you can feel confident about having them repaired.