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Furnace Repair in Boulder, CO: gas furnace and ductwork in a basement mechanical room

Furnace Repair in Boulder, CO

Expert Furnace Repair by Experienced Technicians

A furnace that will not light turns the whole house against you. Our experienced technicians diagnose and repair furnaces across Boulder fast, often the same day you call.

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Our technicians who handle Furnace Repair in Boulder, CO
Why Choose Us

Trusted Local Experts in Boulder

Whether it's a furnace that won't ignite or a full heat pump conversion, Boulder HVAC has the training and equipment to keep Boulder homes comfortable quickly and effectively. No shortcuts, no oversold replacements.

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From the hallway, a furnace that will not heat looks the same no matter what broke. Inside the cabinet, though, everything happens in a strict order: inducer on, pressure switch closed, igniter glowing, gas valve open, burners lit, flame proven, and finally the blower moving heat through the ducts. Most of the diagnosis comes down to finding the broken link. In Boulder homes, it tends to be the same handful of culprits: a flame sensor coated in oxide, a hot surface igniter cracked by thermal cycling, a pressure switch held open by a tired inducer or a plugged condensate trap, or a control board with a burned relay.

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Any Make or ModelCode-compliant work

Cooling trouble instead? See AC Repair.

Warning Signs for Furnace Repair

Recognizing the warning signs early can save you time and money. Watch for these telltale signs:

  • A flame that burns soft and yellow rather than steady blue
  • A furnace that shuts off every few minutes before the house warms up
  • Rust streaks, soot, or water around the cabinet or flue
  • Squealing or grinding from the blower compartment
  • The igniter glows and clicks, yet no flame ever appears
  • The blower runs constantly but the air never warms
  • A bang or boom when the burners ignite late
  • Repeated shutdowns just seconds after the burners light

Don't Wait for a Total Failure

What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. At the first hint of a problem, call (970) 602-4925 for a fast inspection.

Gas furnace with the burner panel off and a new igniter ready in Boulder, CO
With the burner panel off, the igniter, flame sensor and burners can all be checked in a few minutes.
How We Work

How We Handle Furnace Repair

Rather than guess, Boulder HVAC tests the sequence stage by stage. We read igniter resistance, measure flame signal in microamps, check that the pressure switch responds to real inducer draft, confirm voltage at the gas valve, and test the blower and its capacitor. Because this is a fuel-burning appliance, the safety basics come with every visit: the heat exchanger gets inspected, gas connections get leak-tested, and draft gets verified. You cannot tell a furnace problem from a furnace hazard by looking at the thermostat. Before we leave, temperature rise is measured against the data plate so airflow and flame are matched as the manufacturer intended.

Boulder HVAC services natural gas, propane, and electric furnaces from all major brands, from standard 80 percent units to condensing high-efficiency models with their traps, drain lines, and dual pressure switches. Our trucks carry the parts that really fail, such as igniters, flame sensors, pressure switches, capacitors, inducer assemblies, and blower motors, so a typical no-heat call ends with the house warming up. Call (970) 602-4925 for furnace repair anywhere in Boulder, and we can have someone out today.

What It Costs

How Much Does Furnace Repair Cost in Boulder?

Most furnace repairs in Boulder cost between $150 and $600. Ignition and sensor problems are usually the least expensive, while blower motors, control boards, and heat exchangers cost more. Boulder HVAC tests the system, finds the actual fault, and quotes the repair before any work begins.

What Affects the Price

  • Furnace age and type, because 90%+ efficiency models have more specialized parts
  • Whether a cracked heat exchanger is found, which usually means replacement rather than repair
  • Timing, such as a no-heat call on a cold night versus a scheduled repair
  • How easy the furnace is to reach

If your furnace is past 15 to 20 years old or the repair is a major one, we'll give you repair and replacement prices side by side. Call (970) 602-4925 to get your price.

RepairTypical costWhat it usually means
Flame sensor cleaning or replacementBurners light but cut out almost immediately$80–$250Burners light but cut out almost immediately
Hot surface igniter replacementNo ignition; one of the most common winter failures$150–$400Furnace clicks and tries to start but never lights
Draft inducer motorStartup fan fails, furnace won't fire$400–$1,000Loud humming or grinding at startup, then lockout
Blower motorNo airflow, or the blower runs nonstop$400–$1,500Burners run but little or no air comes out of the vents
Control boardErratic behavior, error codes, or no response at all$300–$700Furnace won't respond to the thermostat
Gas valve replacementValve fails to open, so the furnace never lights$250–$700Valve fails to open, so the furnace never lights

Ranges are typical for these repairs; you get an exact quote before any work starts.

How It Works

Our Furnace Repair Process

Our systematic workflow delivers thorough, lasting results on every job.

1

Sequence Diagnosis

We run the furnace through its startup while we measure inducer draft, pressure switch response, igniter resistance, flame signal, and gas valve operation. The goal is to pinpoint the exact step that fails.

2

Safety Inspection

The heat exchanger is inspected, gas connections are leak-tested, and flue draft verified on every visit. A furnace repair that is not proven safe is not finished.

3

Same-Visit Repair

We fix the confirmed fault, and since igniters, flame sensors, pressure switches, capacitors, and motors are on the truck, most furnaces are heating again the same visit.

4

Full Verification

We finish with a full-cycle test: temperature rise matched to the data plate, smooth ignition with no booming, and every limit switch and safety control confirmed working.

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FAQ

Your Furnace Repair Questions Answered

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A well-maintained gas furnace typically delivers fifteen to twenty years, and electric furnaces often longer. Filters and annual service are what separate the twenty-year units from the twelve-year ones. If yours is in that range and facing a major repair, we will give you an honest read on whether it is worth it. Call (970) 602-4925 in Boulder for straight answers.
Almost always a flame-proving problem: the sensor is coated in oxide and cannot confirm the burners are lit, so the board shuts the gas valve within seconds. Three failed tries usually triggers a lockout. Cleaning helps, but a sensor that fouls repeatedly is telling you something. Call (970) 602-4925 and we will fix the cause in Boulder.
It should not be ignored. That boom is delayed ignition: gas pools in the burner area and lights all at once, most often because the burners are dirty or the igniter is weak. Every one of those startups strains the heat exchanger. Handled early, it is a routine repair. Call (970) 602-4925 before it becomes an expensive one.
It depends on where the startup stops. No glow from the igniter usually means the igniter is cracked or the board is not powering it. A glowing igniter with no flame points to the gas valve or the circuit that controls it. And if the click is followed by nothing at all, the pressure switch may not be closing because the inducer is weak or the flue is blocked. We test every step. Call (970) 602-4925 for a diagnosis.
Safety First

The Benefits of Professional Furnace Repair

The most serious furnace problem is usually hidden. A cracked or corroded heat exchanger can let combustion gases into the airstream, and nothing about it is visible from the outside of the cabinet. Delayed ignition makes things worse, because each boom at light-off puts more stress on that metal. Add high voltage, a gas valve, and a flue to the same box, and there is little room for guesswork. Diagnosis is full of traps too. A high limit that keeps tripping could be a bad switch, or it could be doing exactly its job because a filter is clogged or the blower is dying, and swapping out a working switch only hides the real fault.

At Boulder HVAC, no symptom gets treated in isolation. A meter tells us the flame signal, so we never condemn a good sensor while the real culprit, a cracked igniter or a weak gas valve, keeps causing trouble. We confirm draft at both the pressure switch and the flue, measure temperature rise against the data plate to flag airflow problems early, and test the gas side with a leak detector, not a guess. When we are done, the furnace has proven itself safe and correct through a full cycle, and if it is nearing the end of its useful life, you will get an honest assessment.

Comparing DIY and Professional Furnace Repair

Online tutorials may help in a pinch, yet lasting repairs and code-compliant installs depend on trained technicians.

FactorDIY AttemptProfessional Service
Exchanger Cracks Cracks invisible from the outside Checked every time we open the unit
Ignition Faults Guesswork based on blink codes Each ignition component tested
Gas Safety A loose union goes unnoticed Every fitting checked with a detector
Limit Trips A safety device jumpered out Root cause of overheating corrected
Airflow Match Fan speed never checked Blower tuned to the rated rise
Verification It lit once, call it fixed Complete cycles tested before we leave
Gas furnace and PVC venting in a basement utility room in Boulder
Homeowner Tips

How to Prevent Furnace Repair Problems

Smart maintenance is almost always cheaper and easier than an early replacement. Here are our expert recommendations:

  • Keep the condensate trap and drain clear on high-efficiency units to prevent lockouts
  • Give the furnace room to breathe, since a crowded utility space starves the burners of air
  • Put in a fresh filter monthly through the heating season, the cheapest protection your furnace can get
  • Clear boxes, lint, and above all chlorine-based cleaners out of the furnace area
  • Have the furnace checked every autumn, while a weak igniter or fouled sensor is still an easy fix
  • Listen at light-off; clean ignition is quiet, and booming means the burners need service
  • Put a carbon monoxide detector on every level and test them monthly

Get Furnace Repair Help Today

The sooner you call, the sooner your comfort is back.

Get Help: (970) 602-4925

Where We Provide Furnace Repair

We serve Boulder and its neighboring communities for furnace repair, from quick same-day repairs to planned installs.

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Our Services

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The Boulder HVAC Difference

Our Commitment to Boulder Residents

We've built our reputation in Boulder through honest work, fair pricing, and furnace repair results that last.

Safe, By-the-Book Installs

Cut corners on an HVAC install and you invite refrigerant leaks, carbon monoxide, and early failure. We do it by the book on every job, every time.

Repairs That Last

We dig deeper than the symptom, from error codes to static pressure, so your comfort stays reliable long after we leave.

Honest, Upfront Pricing

Before we lift a finger, you'll know the full scope and the exact price, no fine print and no pressure to add on extras.

Your Boulder Neighbors

Being a family-run business in Boulder means our reputation rides on every job, so we never cut corners.

★★★★★ Rated 5.0/5 by Boulder homeowners  ·  Upfront Pricing  ·  Fast Response  ·  All Brands Serviced

Schedule Your Furnace Repair Today

Protect your home and your peace of mind today, Boulder HVAC can have a technician out to you soon.

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