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. Diagnosis is mostly a matter of finding where that chain breaks. In Marietta 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.
Marietta HVAC repairs furnaces by testing the sequence, not guessing at it. Our experienced technicians watch the startup step by step and measure at each stage: 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: the heat exchanger inspected, connections leak-tested, and draft confirmed, 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.
Conventional or condensing, gas, propane, or electric, we repair them all, across every major brand, including the traps, drains, and dual pressure switches that come with high-efficiency models. The parts most likely to fail are stocked on every truck: igniters, flame sensors, pressure switches, capacitors, inducer assemblies, and blower motors. That is why the majority of no-heat calls end the same visit. If your furnace is down anywhere in Marietta, call (770) 202-3453 and we will get the burners lit today.
For air conditioning breakdowns, see AC Repair in Marietta.
How Much Does Furnace Repair Cost in Marietta?
The typical furnace repair in Marietta lands between $150 and $600. The price depends on which part failed and how old the furnace is. You'll get a written, upfront price from Marietta HVAC after we diagnose the problem.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Flame sensor cleaning or replacementBurners light but cut out almost immediately | $80–$250 | Furnace lights, then shuts off within seconds |
| Hot surface igniter replacementFurnace clicks and tries to start but never lights | $150–$400 | Furnace clicks and tries to start but never lights |
| Draft inducer motorStartup fan fails, furnace won't fire | $400–$1,000 | Startup fan fails, furnace won't fire |
| Blower motorBurners run but little or no air comes out of the vents | $400–$1,500 | No airflow, or the blower runs nonstop |
| Control boardFurnace won't respond to the thermostat | $300–$700 | Furnace won't respond to the thermostat |
| Gas valve replacementIgniter glows but gas never flows to the burners | $250–$700 | Valve fails to open, so the furnace never lights |
Ranges are typical for these repairs; you get an exact quote before any work starts.
Factors That Change the Price
- Furnace age and type, because 90%+ efficiency models have more specialized parts
- A cracked heat exchanger, which is a safety issue and usually points to replacement
- Timing, such as a no-heat call on a cold night versus a scheduled repair
- How easy the furnace is to reach
When a repair gets expensive on an aging furnace, you'll see both options before deciding. Call (770) 202-3453 to get your price.
Warning Signs for Furnace Repair
Catching these issues early helps you avoid costly problems and protect your property. Watch for these telltale signs that professional help is needed:
- A bang or boom when the burners ignite late
- A pilot or burner flame that is lazy yellow instead of crisp blue
- Burners light, run a few seconds, then shut down repeatedly
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- The igniter glows and clicks, yet no flame ever appears
- Grinding or high-pitched squeals from the blower
- Frequent on-off cycling that never reaches the thermostat setting
- A fan that keeps running while the registers blow cool air
Act Before It Gets Worse
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. If you notice any of these signs, contact Marietta HVAC at (770) 202-3453 for a prompt inspection.
Furnace Repair Issues? We Can Help.
Our experienced technicians are standing by to help.
Call (770) 202-3453 TodayFrequently Asked Questions About Furnace Repair
Why Hire a Professional for Furnace Repair?
Gas, open flame, high voltage, and a flue 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. Replacing the switch when the real issue is airflow removes a safety device and leaves the actual problem in place.
At Marietta 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, stays in place. We confirm draft at both the pressure switch and the flue, measure temperature rise against the data plate to catch 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, we tell you honestly.
What to Expect From Our Furnace Repair
Our systematic workflow delivers thorough, lasting results on every job. Here's what you can expect when you choose Marietta HVAC:
Step-by-Step Diagnosis
Instead of guessing, we follow the startup sequence step by step, with readings on the inducer, pressure switch, igniter, flame sensor, and gas valve, until the broken link shows itself.
Combustion Safety Check
Safety is part of every repair: heat exchanger inspection, instrument leak testing on the gas side, and flue draft verification, because a furnace that runs is not the same as a furnace that runs safely.
Same-Visit Repair
We fix the part that actually failed, and since igniters, flame sensors, pressure switches, capacitors, and motors are on the truck, most furnaces are heating again the same visit.
Complete Verification
Before we head out, the furnace runs full cycles while we check temperature rise against the data plate, listen for clean, quiet ignition, and test each limit and safety control.
Furnace Repair Prevention Tips
Taking preventive measures can help you avoid costly heating and cooling problems down the road. Start with these practical measures our team relies on:
- If you have a high-efficiency furnace, check that the condensate drain is flowing freely
- Keep storage, lint, and especially chlorine-based products away from the furnace closet
- Book a fall tune-up so weak igniters and fouled sensors are caught before the first freeze
- Listen at light-off; clean ignition is quiet, and booming means the burners need service
- Keep a working carbon monoxide alarm on every level of the home and check it each month
- Change the filter monthly during heating season; it is the cheapest furnace part you will ever buy
- Give the furnace room to breathe, since a crowded utility space starves the burners of air
Comparing DIY and Professional Furnace Repair
Online tutorials may help in a pinch, yet lasting repairs and code-compliant installations usually depend on professional methods and trained technicians. Here's a comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Exchanger Cracks | Cracks invisible from the outside | Inspected on every repair visit |
| Ignition Faults | New igniter installed on a hunch | Each ignition component tested |
| Gas Safety | Connections judged by smell | Connections leak-tested with instruments |
| Limit Trips | Limit replaced, cause left behind | The airflow fault behind the trip found |
| Blower Setup | Airflow assumed, not measured | Temperature rise set to the data plate |
| Final Check | One good start and done | Complete cycles tested before we leave |
Schedule Your Furnace Repair Service
Don't let a failing system get worse. Call Marietta HVAC now for prompt, professional service.
Call (770) 202-3453 TodayWhere We Provide Furnace Repair
We bring furnace repair to homes and businesses in town and across the nearby communities. Pick your area to see local details.