Elmhurst HVAC: Quick Fixes for Common Heating System Issues

Estimated Read Time: 9 minutes

Freezing night, no heat, and Google open on your phone searching “furnace repair near me”? You are not alone. In Glendale Heights and across DuPage County, winter lows often dip into the teens, so a reliable furnace is non‑negotiable. Below are the top five furnace problems homeowners face, with quick DIY checks to try before you call. You will also see clear signs for when it is smarter to bring in a pro, so you restore heat fast and avoid bigger bills.

1) Furnace Blowing Cold Air or No Heat

A cold blast from the vents usually points to one of three things: thermostat settings, restricted airflow, or a safety lockout.

Try these quick checks:

1. Verify the thermostat.
2. • Set to Heat, fan Auto, and a temperature above the current room temp.
   • Replace batteries if the screen is dim or blank.
2. Inspect the air filter.
3. • A clogged filter can overheat the heat exchanger, trip the limit switch, and force a cool‑air cycle.
   • Replace a 1‑inch filter every 1 to 3 months during heavy use.
3. Check the breaker and furnace switch.
4. • Confirm the furnace switch is On and the breaker is not tripped.
4. Look at the furnace status light.
5. • A blinking diagnostic code often signals a lockout. Power cycle the furnace for 30 seconds, then restore power to clear minor faults.

When to call a pro:

• The limit switch or flame sensor keeps tripping. Cleaning or replacing sensors requires safe disassembly and gas handling.
• You smell gas. Leave the home and call a licensed technician right away.
• Repeated lockouts continue after filter and thermostat checks.

Why quick action matters: Running a furnace with airflow restrictions can crack the heat exchanger. That risks carbon monoxide exposure and an expensive replacement.

2) Short Cycling: Furnace Starts, Stops, Repeats

Short cycling wastes energy, stresses parts, and leaves rooms chilly. Common triggers include dirty filters, blocked vents, an oversized furnace, or a malfunctioning flame sensor.

What you can do now:

1. Replace the filter and open vents.
2. • Ensure supply and return vents are clear of furniture and rugs.
2. Check the thermostat location.
3. • If it sits near a heat source or sun‑exposed window, it can end the cycle too soon.
3. Gently clean the flame sensor.
4. • If comfortable, power down the furnace, remove the flame sensor, and lightly clean the rod with a non‑abrasive pad. Reinstall securely.

Professional fixes:

• Recalibrate gas pressure and verify combustion.
• Test the high‑limit switch and inducer motor.
• Diagnose sizing and duct static pressure. An oversized furnace or high static will keep cycles short and comfort uneven.

Efficiency insight: Short cycling can spike bills by 10 to 15 percent in peak season because the furnace never reaches steady‑state efficiency.

3) Odd Noises: Banging, Screeching, or Rattling

Your furnace should be heard, not loud. New or worsening noises signal a problem.

Common sounds and what they mean:

• Banging at startup
• • Often delayed ignition or expanding ductwork. Delayed ignition needs immediate attention to avoid burner damage.
• Screeching or squealing
• • Worn blower motor bearings or a loose belt on older units.
• Rattling or vibrating
• • Loose access panels or duct screws. Tighten hardware and add foam gasketing as needed.
• Humming that gets louder
• • Failing blower motor capacitor drawing excess current.

DIY first steps:

1. Tighten panels and visible duct screws.
2. Replace the filter to reduce blower strain.
3. If you hear metal‑on‑metal scraping, shut the system off. That may be a blower wheel issue.

Call a pro if:

• You suspect delayed ignition, gas valve problems, or capacitor failure.
• The noise continues after the simple checks. Pro testing includes amperage draw, capacitor microfarad readings, combustion analysis, and gas pressure verification.

4) Weak Airflow or Rooms That Never Get Comfortable

If the thermostat reads 70 but a bedroom feels like 62, you have an airflow problem.

Likely causes:

• Clogged filter or undersized return air.
• Closed or blocked supply vents behind furniture.
• Leaky or crushed ducts in the attic or crawlspace.
• Blower speed set incorrectly for your duct static pressure.

How to improve airflow fast:

1. Replace the filter and open all supply and return vents.
2. Inspect accessible ducts for kinks, loose connections, or gaps.
3. Close fireplace dampers when not in use to reduce heat loss.
4. Use a simple tissue test at vents. If it barely moves, airflow is low.

Professional solutions:

• Measure total external static pressure and adjust blower tap settings.
• Seal and balance ducts, then add or resize returns in starved rooms.
• Upgrade to a high‑efficiency ECM blower that maintains airflow across pressure changes.

Local tip: Glendale Heights winters are dry and cold. Proper airflow helps your humidifier work correctly, keeping wood floors and furniture from cracking while you stay comfortable.

5) Pilot Light or Ignition Failure

Modern furnaces use hot surface igniters or spark ignition. Older models have standing pilots.

Quick checks:

1. Confirm gas supply.
2. • Make sure the gas valve feeding the furnace is open.
2. Reset after a brief power cycle.
3. • Turn the furnace switch off for 30 seconds, then back on.
3. For standing pilots, follow the lighting instructions on the furnace sticker exactly. If the pilot will not stay lit, the thermocouple may be faulty.

Professional diagnostics:

• Test igniter resistance and replace if out of spec.
• Verify flame signal microamps to ensure the board sees a stable flame.
• Inspect and clean burners to prevent delayed ignition.

Safety fact: A contaminated flame sensor can prevent ignition, which is a designed safety. Bypassing sensors is dangerous. If you are unsure, call a licensed tech.

Prevent Breakdowns With Pro Maintenance

Most emergency calls we see in peak winter could have been prevented with routine service. Our technicians follow a detailed process during heating tune‑ups to protect your investment.

What a pro tune‑up includes at Summers PHC:

1. Clear debris from coils and heat transfer surfaces to maintain airflow.
2. Check refrigerant levels for heat pumps and watch for leaks.
3. Adjust and test the thermostat for accuracy.
4. Review wiring and electrical parts for safety.
5. Lubricate moving components to reduce wear.
6. Flush the condensate drain to prevent water buildup.
7. Verify defrost cycle and reversing valve on heat pumps.
8. Clean or replace filters to improve indoor air quality.

Boiler customers also benefit from a gas leak detection and pressure evaluation, calibration of control devices and timers, and deep cleaning of internal components like the heat exchanger to restore efficiency.

Two hard facts to trust:

• Summers PHC provides 24/7 emergency HVAC service with licensed, drug‑tested, and background‑checked technicians so help is available any time.
• Our maintenance plan delivers two professional A/C and heating tune‑ups every year, priority booking, and member discounts, giving you predictable comfort and fewer surprise repairs.

When To Repair vs. Replace

Consider replacement when:

1. Your furnace is 15 to 20 years old and repairs are frequent.
2. The heat exchanger is cracked or leaking. That is a safety issue.
3. Repair costs exceed 30 to 40 percent of a new, efficient unit.

Benefits of a modern high‑efficiency system:

• Quieter, steadier heat with variable‑speed blowers.
• Lower utility bills from higher AFUE ratings.
• Better airflow and comfort across rooms when paired with duct improvements.

Summers PHC offers free equipment estimates on new high‑efficiency furnaces and flexible financing with payments as low as affordable monthly options, subject to approval and terms.

Special Offers for Glendale Heights Homeowners

• Special Offer: $69 Heating Tune‑Up. Must present at time of service. Schedule by 2/28/26.
• Free quotes on any furnace installation project. Best‑price guarantee to match or beat competitor pricing. Offer valid through 3/04/26.
• Financing Offer: Payments as low as $75 per month on a high‑efficiency furnace. Call for details. Expires 2/28/26.

Ready to save and get reliable heat fast? Call (331) 294‑8710 or book online at https://summersphc.com/glendale-heights/. Mention the $69 Heating Tune‑Up when you schedule.

What Homeowners Are Saying

"I switched my furnace service from Four Seasons at my son's suggestion, and I couldn't be happier. Summers has definitely earned a 5 out of 5 on servicing my furnace, air conditioner and humidifier. I would recommend them to anyone looking for a knowledgeable and reasonable HVAC company."
–Julie F., Furnace Service

"Our service technician Efrain was experienced and knowledgeable about fixing and maintaining our furnace. He offered a lot of insight towards keeping the furnace in top notch condition. Overall exceptional service provided - 5 stars!"
–Nicholas C., Furnace Repair

"Efrain came out today and he did a wonderful job. Efrain did a great job on cleaning our furnaces did a complete and thorough job recommended a few things that we knew we needed to get done. He was thorough, polite, and very knowledgeable."
–Carol S., Furnace Maintenance

"Outstanding Furnace Repair Service! I had an issue with my furnace, and Efrain came out right away. He was professional, friendly, and clearly knew what he was doing. He diagnosed the problem quickly, explained everything in simple terms, and had my heat running perfectly again in no time."
–Bradley W., Heating Repair

Frequently Asked Questions

Why is my furnace running but not heating?

Check thermostat settings, replace a clogged filter, and verify breakers. If the furnace still blows cool air, the high‑limit switch or flame sensor may need service.

How often should I replace my furnace filter in winter?

During heavy use, replace a 1‑inch filter every 1 to 3 months. Thicker media filters can last 3 to 6 months but should be inspected monthly.

Is it safe to relight my pilot light myself?

Yes, if your furnace has a standing pilot and you follow the lighting instructions on the unit. If the pilot will not stay lit, call a licensed technician.

What temperature should I set my thermostat to save money?

Try 68°F when awake and lower by 7 to 10°F overnight. A programmable or smart thermostat can automate these setbacks for consistent savings.

Do I need annual furnace maintenance?

Yes. Annual service catches problems early, improves safety, and keeps efficiency up. Members at Summers PHC get two tune‑ups a year with priority booking.

Bottom Line

The fastest way to restore heat is to handle simple checks first, then call a licensed pro when safety or repeated shutdowns appear. If you need furnace repair near me in Glendale Heights, Summers PHC is ready 24/7 with upfront pricing and a worry‑free guarantee.

Schedule Now

Call (331) 294‑8710 or book at https://summersphc.com/glendale-heights/. Ask for the $69 Heating Tune‑Up before 2/28/26 or request a free estimate on a new high‑efficiency furnace. Stay warm, safe, and comfortable today.

Ready for Fast Heat?

• Call now: (331) 294‑8710
• Book online: https://summersphc.com/glendale-heights/
• Current savings: $69 Heating Tune‑Up when you schedule by 2/28/26

We will get you warm quickly with licensed techs, stocked trucks, and no surprises on price.

About Summers Plumbing Heating & Cooling

Locally owned and operated, Summers Plumbing Heating & Cooling serves Glendale Heights and nearby suburbs with licensed, drug‑tested, and background‑checked technicians. We offer upfront pricing, 24/7 emergency response, fully stocked trucks, and a price‑match guarantee on installations. Homeowners choose us for fast arrivals, courteous pros, and our maintenance plan that includes two tune‑ups a year, priority scheduling, and member discounts. We back our work with a worry‑free guarantee and provide free second opinions and flexible financing on new systems.