Furnace Repair

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Furnace Repair in Lisle and Downers Grove

Fixing No-Heat Furnace Problems Throughout Chicagoland and surrounding suburbs


CPR has been repairing furnaces in Lisle since 2001. We can quickly determine whether the issue is a cracked heat exchanger or problem with an electrical connect. Call (708) 879-3531 to schedule service with our local heating experts.

Fixing Broken Furnaces Near You Since 2001

Are parts of your home unnaturally chilly? Is there something banging and groaning behind your walls in the middle of the night? Before you call the Ghostbusters, it might be a good idea to reach out to a local furnace repair company. These signs are often experienced by people with a heating problem. And, in most cases, they can be solved by an experienced HVAC technician. To learn more about furnaces and what it takes to fix them, read on.

Give us a call at (708) 879-3531 to schedule residential heating repair in Downers Grove, Naperville, or Lisle .

Signs Your Furnace Has a Problem

There are times when something goes wrong in the heating process. Though this sometimes leads to an obvious problem—a complete furnace breakdown—this isn’t always the case. Much of the time, the signs you need to call a Lisle HVAC contractor are much more subtle. To prevent big problems from snowballing into larger ones, it’s important to be on the lookout for the following:

  • Weird Smells: When you first turn your furnace on for the year, you might notice a musty smell. This is typically dust burning off that settled over the months your furnace sat idle. This will dissipate as the unit operates and isn’t anything to be concerned about. If you notice an odor that suddenly appears or refuses to go away, however, it’s time to call a Lisle HVAC professional.
  • Odd Noises: Is your furnace banging or making some other kind of noise? This can be the result of numerous issues with the unit and is best diagnosed by a heating repair expert. Call (708) 879-3531 to schedule your furnace repair.
  • More Service Calls: Every furnace in Chicagoland and surrounding suburbs will have a part fail and need service in its life. In fact, one out of four people in the US will have an HVAC technician in their home each year. But if you’re making multiple calls in a heating season, it’s a sign you’ve been propping up a system that is aging out. Note that service calls don’t include preventative furnace maintenance visits.
  • Climbing Utility Bills: There are many reasons your electric or gas bills can rise. Cooler temperatures are an obvious reason. But, if your fuel usage suddenly increases dramatically, you probably should have our local HVAC experts take a look. This increased cost often indicates a furnace that's being pushed past its limit.
  • Visual Rust: While some amount of rust is expected with age, excessive amounts—especially on the flue—can be a sign of improper venting. If a roof or plumbing leak is causing furnace corrosion, it’s not just an eyesore. It can be dangerous. If the system rusts through to the heat exchanger, your home could be contaminated with deadly carbon monoxide. So, if you notice an issue with furnace rust, give CPR a call.
  • Frequent Cycling: If your furnace is constantly turning on and off, there’s something stopping the unit from working properly. Unfortunately, this can be difficult to diagnose due to a variety of potential causes. To get the problem located and fixed quickly, rely on our heating experts.
  • Start-Up Problems: Does your furnace not turn on when it drops below the indicated temperature on your thermostat? Are you hearing clicking noises on start-up? These issues often signal an upcoming furnace breakdown. So, if you ever notice them, reach out to CPR by phone or form.

Fortunately, no matter the scope or size of the problem, our HVAC experts can handle your residential furnace repair. Though we do most of our work in Naperville, Downers Grove, and Lisle , we are also well known and trusted throughout the surrounding areas.

The Top 5 Causes of Furnace Failure

It’s important that homeowners understand what parts of their furnace are most likely to fail. This can better prepare them to communicate with us about their heating problems. It also allows us to quickly fulfill your heating repair needs in Chicagoland and surrounding suburbs. When fixing heating systems, we often find the following culprits, some of which can save you a service call:

  1. Clogged Filters: When was the last time you swapped out your furnace filter? If the answer is more than a few weeks ago, it might be time to check it, especially if you have pets. When running, your heating system pulls in dust, dander, and dirt. This is kept out of the mechanical parts by your furnace filter. A clogged filter restricts airflow, making your heating system work harder. Replacing it not only helps efficiency, but also improves air quality.
  2. Bad Thermostats: Your thermostat is responsible for signaling your furnace when to turn off and on to maintain the set temperature. If it’s not working properly, you’ll struggle to get warm. For instances where the thermostat may be at fault, make sure its batteries are good, if it uses any. Also, double-check that it is set to HEAT with the run method on AUTO.
  3. Ignition Failure: Sometimes the pilot light or surface ignitor will fail and refuse to light the burners. If this happens your furnace won’t be able to heat the air, leaving you in the cold. To prevent this, have it checked and cleaned regularly by our HVAC professionals.
  4. Exhaust Blower Issues: The furnace exhaust blower is what takes the combustion gases out of the heat exchanger and vents it safely outdoors. If this component fails, the furnace will cycle on and off or shut down. Regular inspections and maintenance visits can prevent this from happening.
  5. Blower Motor Failure: The blower motor is essentially what keeps the air moving around your home. Should this component fail, it doesn’t matter how efficient your furnace is, the hot air won’t be distributed around your home. The blower can fail from overheating or from it becoming clogged with debris. Have your ducts cleaned and your furnace tuned up to keep the blower working effectively.
  6. Bad Heat Exchanger: The heat exchanger is one of the most important components of a conventional furnace. It is the component that safely transfers heat from the flame into heated air that is circulated in the home. When the heat exchanger develops holes or cracks, replacing it can be quite expensive. Some people prefer to simply replace their furnace. An expert evaluating your system can best advise you. If the stress on your heat exchanger is due to excess cycling due to having too large of a furnace, only replacing the heat exchanger will result in the same problem developing again.

Trust Us to Tackle Your Furnace Problems in Chicagoland and surrounding suburbs

When it comes to furnace repair in Downers Grove, we know you have plenty of HVAC companies to choose from. However, not all of them are equal.

When you need your furnace repaired or replaced, trust the experts at CPR Mechanical! As our long list of happy customers shows, many of your neighbors already do! With 25 years of experience helping people in the Naperville area, we have the know-how necessary to fix your broken furnace or replace the old one. No matter what you need, our company has well-defined services and procedures to ensure the job's done right. In other words, when it comes to furnace repair, you can always count on CPR Mechanical for quality products and workmanship. Contact us today to schedule your furnace repair.

Frequently Asked Questions - Furnace Repair

When your furnace in Naperville or Chicagoland and surrounding suburbs blows cold air, a number of things could be to blame. Start by checking your thermostat to ensure it’s set to heat. If the thermostat isn’t the issue, the problem could be with the flame sensor or ductwork leaks. Our local HVAC technicians will quickly diagnose and fix the problem for you.

Furnace repair costs vary based on the issue. Smaller problems like sensor replacements can cost as little as $100, while major repairs like heat exchanger replacements may cost thousands. Most standard repairs range between $300 and $800. Older systems tend to have more expensive issues, so regular maintenance is key.

Before contacting a professional for furnace repair in Downers Grove or Lisle , check these items:

  • Replace dirty air filters
  • Confirm your thermostat is set correctly
  • Ensure the pilot light is lit
  • Verify the furnace circuit breaker hasn’t tripped
  • Open any closed air vents

If these steps don’t solve the problem, call CPR for professional assistance.

If your furnace in Downers Grove or Lisle is making unusual noises, it’s likely due to a mechanical issue. Common causes include:

  • Dirty burners causing booming sounds
  • Cracked heat exchangers making popping noises
  • Faulty blower motors buzzing or grinding
  • Loose screws or bolts rattling during operation
  • Expanding or contracting ductwork

Ignoring these noises could lead to further damage. Contact (708) 879-3531 to schedule a repair.

Some signs it’s time to call for furnace repair in Chicagoland and surrounding suburbs include:

  • Persistent burning smells
  • Thermostat error codes
  • The furnace cycling on and off frequently
  • Weak airflow or no heat
  • Unusual popping or banging noises
  • A sudden increase in energy bills

Contact (708) 879-3531 to schedule a repair if you notice these issues.

Water leaking from a furnace might seem odd, but newer high-efficiency systems often create condensation. Common causes include:

  • Clogged condensation drains
  • A damaged heat exchanger
  • Faulty condensate pumps
  • Air conditioner or humidifier issues

Leaking water can damage your furnace, so call (708) 879-3531 to address the problem right away.

Older furnaces in Lisle may have a standing pilot light that occasionally goes out. To safely relight it:

  1. Turn off the gas and wait five minutes.
  2. Adjust the gas valve to “Pilot” and press the reset button.
  3. Use a long lighter to ignite the flame.
  4. Once the light is steady, release the button and turn the valve to “On.”

If it doesn’t stay lit, contact CPR for assistance.

A cracked heat exchanger is a serious safety issue for furnaces. It can cause incomplete combustion, allowing carbon monoxide—a deadly gas—to leak into your home. Replacing a heat exchanger in Lisle is costly, so it’s often more economical to replace the entire furnace. Our experts can assess the best option for your home.

If your furnace seems to be running endlessly, it’s likely due to a thermostat malfunction, clogged air filters, dirty flame sensors, or an obstructed flue. These issues waste energy and can overheat your system. Call (708) 879-3531 for fast diagnosis and repair.

A cheaper repair might seem like a good deal, but it often leads to problems like:

  • Inferior parts that fail quickly
  • Incomplete system inspections
  • Unskilled technicians
  • Pushy contractors recommending unnecessary replacements
  • No warranty on the work

Choose CPR for reliable, high-quality furnace fixes in Chicagoland and surrounding suburbs.

At CPR, we repair all major furnace brands in Downers Grove, including Lennox, Carrier, Trane, and Goodman. No matter the make or model, our experienced technicians know how to diagnose and fix any issue your system might have.

Loud furnaces in Lisle or Naperville are often due to high fan speeds, unbalanced ductwork, or obstructions. Start by lowering the blower fan setting, if possible. If that doesn’t work, call (708) 879-3531 to adjust the system for quieter operation.

Strange smells from your furnace in Chicagoland and surrounding suburbs are often caused by:

  • Burning dust during startup
  • Mold or mildew in the system
  • Electrical burning from a short circuit*
  • Rotten egg smells from a gas leak*
  • Grime in the heat exchanger

If you smell gas or burning, turn off your furnace and call (708) 879-3531 immediately.

Routine maintenance is key to extending your furnace’s lifespan. Schedule annual tune-ups with CPR, replace filters regularly, and address minor issues like strange noises or thermostat problems before they worsen. Preventative care helps avoid costly repairs.

If your furnace clicks on and off repeatedly, it might be time to clean the flame sensor. Here’s how:

  • Turn off power and gas to the furnace
  • Locate the flame sensor near the burner
  • Remove the sensor and clean it with fine-grit sandpaper
  • Replace the sensor and restore power

If you’re uncomfortable doing this, call CPR for help.

While minor fixes like changing filters are fine for DIY, most furnace repairs should be left to professionals. Furnaces involve electrical, gas, and mechanical components, making them potentially hazardous. For safe and effective furnace repairs in Lisle , contact CPR.

Breathing New Life into HVAC Systems in Downers Grove and Lisle

Take a Look At What Your Neighbors Had to Say

  • CPR mechanical has done many HVAC jobs for me over the years. They always show up and do a great job. They give me plenty of options at various price points so I can make the final decision. I would highly recommend them for HVAC work.
    - Kerry H.
  • I'm so fortunate to have CPR MECHANICAL as my go to HVAC company. As a small business owner, I appreciate the rapid response to my SOS calls. Service is reliable, fair and timely.
    - Angie W.
  • CPR Mechanical has been my heating/cooling provider for over 10 years now. Excellent service and very reliable.
    - Norma R.
  • Excellent service. Installed Heat Pump and Air Handler. Handed all issues with professionalism. I would recommend the company.
    - Diane J.
  • I had an entirely new system installed. They are very dedicated to customer service. It's highly recommend calling on them but don't wait until things are broken! They are very experienced and are in demand when weather spikes either up or down. If you're questioning if you need service, call them now and get it scheduled.
    - Dean P.
  • Christopher was absolutely amazing! He listened attentively to all of my concerns and questions and took the time to explain everything in a way that was easy for me to understand. He performed maintenance on my air conditioning unit and also corrected a few other issues that needed attention. I especially appreciated that he was able to fit me into his busy schedule.
    - Theresa D.

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