Top 5 Common Furnace Issues for Westminster, CO Homeowners

Sweater season is here! While it’s tempting to cozy up with a blanket to watch the Broncos game, that won’t quite cut it once temperatures drop. A working furnace is essential to keep your home warm and comfortable for your family.

In my 10+ years as an HVAC technician, I’ve seen all kinds of unexpected, costly emergencies—many of which could have been prevented. In this article, I’ll cover the most common issues and how you can prepare your furnace for the cold months ahead.

Key Furnace Breakdown Warning Signs

Is your furnace showing signs of wear? Pay attention to these warning signs that could indicate it’s time for a checkup:

• Higher-than-usual energy bills
  A sudden increase in heating costs can mean your furnace is working harder than it should and losing efficiency.
• Cool air coming from vents
  If the air from your vents isn’t warm, your furnace could malfunction or struggle to reach the correct temperature.
• Aging system (10+ years or older)
  Furnaces typically last 15-20 years. If yours is nearing or has already surpassed the 15-year mark, it’s time to consider an upgrade.
• Difficulty starting or frequent cycling
  If your furnace has trouble starting or turning on and off repeatedly, there may be a problem.
• Inconsistent heating
  Uneven temperatures or cold spots in your home could indicate an issue with airflow or a malfunctioning part.
• Strange noises and odors
  Grinding, popping, or rattling sounds and smells of burning or dust can signal mechanical failure or potential safety issues.

If you see any of these signs, it’s best to consult an experienced professional to evaluate your furnace’s condition.

What Are the Top Furnace Problems in Westminster and the Metro Denver Region?

Denver’s harsh winter months significantly strain furnaces, requiring them to work hard for extended periods. Colorado homeowners rely on their heating systems for safety and comfort, so it's crucial to stay aware of potential issues and take proactive steps to address them.

1. Dirty or Clogged Air Filter

Common signs: 

• Reduced airflow
• Dusty house
• Strange noises
• Allergies

It’s a quick and easy fix–but an essential one. When an air filter is dirty or clogged, your heater has to work harder to draw air into its components, which raises utility bills and adds wear to your system. If the filter gets too blocked, your system may shut down to protect itself from damage.

If you suspect this, check the air filter first. Simply turn off your system, replace the filter, and see if it starts smoothly. If not, there may be a bigger issue.

Tech tip: Swap out air filters every 1-3 months for optimal performance, maximum efficiency, and improved indoor air quality.

2. Worn Blower Motor Components

Common signs:

• Fraying or cracks on the fan belt
• Loud squealing noises
• Belt slipping
• Sudden system shutdown

The blower motor in your furnace powers warm airflow, ensuring even heating throughout your home. Over time, its components can wear out, causing distinctive sounds that signal issues:

• Scraping sound: Worn blower bearings may be the cause. 
• High-pitched squeak: The fan belt may have slipped or worn down.
• Short cycling: Short cycling refers to your system turning off before it has reached the desired temperature. A damaged capacitor can cause this, forcing the system to turn off prematurely and preventing your home from being fully heated.  

Don’t wait for a breakdown–routine checks can save time and money while avoiding inconvenient and costly emergency repairs.

3. Cracked heat exchanger

Common signs: 

• Strange smells
• A yellow, flickering flame
• Unusual noises like popping or rattling
• Carbon monoxide detector going off

The heat exchanger is a critical furnace component, transferring heat from the combustion flame to the air circulating through your home. Its sealed chamber prevents harmful gases, like carbon monoxide, from mixing with indoor air, ensuring safe, efficient heating. However, running your furnace with a dirty filter or overheating your home can cause the exchanger to crack, posing a severe safety risk to your home's air.

If your furnace goes down due to this issue, you need to call an experienced technician to diagnose the issue and replace the exchanger. Regular maintenance can help to detect early signs of wear, saving you from costly emergency repairs and ensuring your home stays safe.

4. Faulty Thermostat

Common signs:

• Inconsistent temperatures
• Frozen or unresponsive display
• No power to the thermostat
• Short cycling

A malfunctioning thermostat is typically easy to spot. If you hear the fan constantly running or notice an inaccurate or blank display, it’s a key indicator. Sometimes, it’s as simple as replacing the battery; other times, it could be a failing power supply or an electrical issue. 

Calling an experienced technician is the quickest way to resolve the issue and prevent additional problems, such as higher energy bills or system malfunctions.  

Tech tip: Consider regular thermostat checks or battery replacements to prevent issues in the future.

5. Malfunctioning ignition or pilot light

Common signs: 

• Gas smell
• Lack of heat
• Strange noises
• Frequent cycling

One of the most essential components of your furnace is the pilot light, sometimes referred to as the ignition control or ignitor. The pilot light produces a healthy blue flame with a slightly yellow tip that burns natural gas to generate heat. The blue flame indicates that your gas furnace is burning the fuel safely and efficiently.

If the pilot light isn't lit, your furnace will not be able to produce heat. Contact a professional immediately if the flame is red, yellow, or any color other than blue. 

Tech tip: Don’t do this alone. Though this issue is easy to recognize, it isn’t easy to fix. Without the help of an experienced technician, burns or other injuries could result.

Be Proactive & Schedule Annual Furnace Maintenance Today

Though it’s typically easy to spot your furnace acting up, fixing it can be another story. By taking a proactive approach, you can maintain your system, increase longevity, and avoid costly emergency breakdowns. 

At L&M HVAC, we provide a thorough tune-up that includes our 21-point inspection. We begin by cycling your furnace and conducting a detailed assessment, followed by a comprehensive report. If any component is outside design specifications—affecting energy efficiency, posing a safety risk, or potentially causing property damage—our technician will provide transparent and honest recommendations for addressing the issues.

Westminster’s Trusted Furnace Experts

Whether your furnace needs maintenance, a quick repair, or is nearing the end of its life, it's essential to work with a trusted professional who can guide you through the process, offer realistic options, and, if necessary, install an upgrade tailored to your home's unique requirements. Whatever you're looking for, contact L&M HVAC for all your furnace needs.