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 sending heat through the house. Most of the diagnosis comes down to finding the broken link. In Florissant 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.
Florissant HVAC repairs furnaces by testing the sequence, not guessing at it. Our experienced technicians verify each stage with a meter rather than a hunch: igniter resistance, flame signal in microamps, pressure switch operation against actual inducer draft, gas valve voltage, and blower and capacitor health. Every visit includes the safety fundamentals on a fuel-burning appliance: heat exchanger inspection, leak-testing of gas connections, and flue draft verification, because the difference between a furnace problem and a furnace hazard is not visible from the thermostat. We measure temperature rise against the data plate before we leave so the fire and the airflow are matched the way the manufacturer intended.
We work on natural gas, propane, and electric furnaces from every major brand, both conventional 80 percent units and condensing high-efficiency models with their traps, drains, and dual pressure switches. The truck stock covers the parts that actually fail: igniters, flame sensors, pressure switches, capacitors, inducer assemblies, and blower motors, so most no-heat calls end with heat the same visit. For furnace repair anywhere in Florissant, call (557) 256-7420 and an experienced technician will be headed your way today.
When the AC quits in summer, see AC Repair in Florissant.
How Much Does Furnace Repair Cost in Florissant?
The typical furnace repair in Florissant lands between $150 and $600. Ignition and sensor problems are usually the least expensive, while blower motors, control boards, and heat exchangers cost more. You'll get a written, upfront price from Florissant HVAC after we diagnose the problem.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Flame sensor cleaning or replacementFurnace lights, then shuts off within seconds | $80–$250 | Furnace lights, then shuts off within seconds |
| Hot surface igniter replacementFurnace clicks and tries to start but never lights | $150–$400 | No ignition; one of the most common winter failures |
| Draft inducer motorStartup fan fails, furnace won't fire | $400–$1,000 | Loud humming or grinding at startup, then lockout |
| Blower motorBurners run but little or no air comes out of the vents | $400–$1,500 | No airflow, or the blower runs nonstop |
| Control boardErratic behavior, error codes, or no response at all | $300–$700 | Furnace won't respond to the thermostat |
| Gas valve replacementIgniter glows but gas never flows to the burners | $250–$700 | Igniter glows but gas never flows to the burners |
Typical ranges for common repairs. Your exact price is quoted after diagnosis.
What Affects the Price
- The age and efficiency of the furnace, since high-efficiency models use more specialized parts
- Whether a cracked heat exchanger is found, which usually means replacement rather than repair
- Same-day or after-hours service versus a planned visit
- Access to the furnace in attics, closets, or crawlspaces
When a repair gets expensive on an aging furnace, you'll see both options before deciding. Call (557) 256-7420 to get your price.
When to Call for Furnace Repair in Florissant
The sooner you notice these red flags, the easier and cheaper the problem is to resolve. These are the signals our technicians see most often when a problem is underway:
- A flame that burns soft and yellow rather than steady blue
- Water, rust stains, or black soot around the flue or cabinet
- Flames that start, last a few seconds, and go out again and again
- Short cycling every few minutes without reaching the setpoint
- The igniter glows and clicks, yet no flame ever appears
- Booming or banging at light-off from delayed ignition
- Squealing or grinding from the blower compartment
- Air moving through the vents that never gets warm
Early Action Saves Money
What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. Don't wait, get Florissant HVAC on the phone at (557) 256-7420 and we'll take a look right away.
Your Furnace Repair Questions Answered
Why Professional Furnace Repair Matters
Gas, open flame, high voltage, and a flue all share one cabinet in a furnace, and the most dangerous failure is the one you cannot see: a damaged heat exchanger that lets combustion gases into the air the blower sends through your home. Every morning that delayed ignition keeps booming at startup, that exchanger takes more stress. The diagnostic side has its own pitfalls. When a furnace trips its high limit, the switch itself may be bad, or the furnace may be protecting itself from a clogged filter or a failing blower. Swapping the switch in that second case removes a safety device and leaves the actual problem in place.
Our experienced technicians treat every symptom as a question about the whole system. Flame signal gets measured rather than assumed, so a healthy sensor is never replaced while a cracked igniter or weak gas valve skates by. Draft is verified at the pressure switch and the flue. Temperature rise is checked against the data plate, which is how airflow problems get caught before they shorten the exchanger's life. And the gas side is leak-tested with instruments, not a sniff and a shrug. The result is a furnace that has been proven safe and correct under a full cycle, and an honest report if the unit is nearing the point where replacement beats another repair.
What to Expect From Our Furnace Repair
We work through a clear, repeatable process so nothing gets overlooked on your property. Here's exactly how the furnace repair process unfolds:
Startup Sequence Testing
The furnace is run 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.
Safety Inspection
On every visit, we inspect the heat exchanger, leak-test the gas connections, and confirm the flue is drafting. A repair is not complete until the unit is proven safe.
Targeted Repair
The typical repair finishes in one trip. The common failure parts, from igniters and flame sensors to pressure switches, capacitors, and motors, are stocked on the truck and ready to go.
Full Verification
We run complete cycles, measure temperature rise against the data plate, confirm clean ignition without booming, and verify every limit and safety control before we leave.
Questions About Furnace Repair?
We provide honest advice and upfront pricing on all furnace repair work.
Get Help: (557) 256-7420How to Prevent Furnace Repair Problems
A little routine maintenance goes a long way toward avoiding a mid-season breakdown. Put these technician-approved steps to work around your property:
- Test your CO detectors monthly and make sure each floor has one
- Change the filter monthly during heating season; it is the cheapest furnace part you will ever buy
- On high-efficiency models, keep the condensate trap and drain line clear and draining
- Book a fall tune-up so weak igniters and fouled sensors are caught before the first freeze
- Notice how the furnace sounds at startup, because a quiet light-off is healthy and a boom is not
- Give the furnace room to breathe, since a crowded utility space starves the burners of air
- Clear boxes, lint, and above all chlorine-based cleaners out of the furnace area
Should You DIY or Call a Pro?
A homeowner can swap a filter with ease, but diagnosing capacitors, refrigerant charge, control boards, and error codes calls for the equipment and know-how only a pro brings. Here's a comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Heat Exchanger | Damage hidden inside the cabinet | Checked every time we open the unit |
| Ignition Problems | New igniter installed on a hunch | Igniter, sensor, and valve each metered |
| Gas Connections | Connections judged by smell | Connections leak-tested with instruments |
| Limit Trips | A safety device jumpered out | The airflow fault behind the trip found |
| Blower Setup | Blower speed left wherever it was | Rise measured and blower adjusted |
| Verification | It lit once, call it fixed | Full cycles proven clean and safe |
Schedule Your Furnace Repair Service
The sooner you call, the sooner your comfort is back. Reach Florissant HVAC for fast service.
Get Help: (557) 256-7420Where We Provide Furnace Repair
Wherever you are in the area, the same experienced team handles your furnace repair. Find your community below.