When a furnace won't light, keeps shutting off, or the limit switch keeps tripping, resetting it doesn't fix the cause. Every Furnace Repair visit includes a carbon monoxide safety check as a standard part of the job, not an upsell.
Furnace failures cluster heavily around a handful of parts — ignitors, flame sensors, gas valves, and heat exchangers — and most no-heat calls come down to one of those four. We test each with a multimeter and combustion analyzer rather than replacing parts on a hunch.
Safety and accuracy on every heating call.
Every furnace repair includes a combustion analyzer reading to check for dangerous CO levels, not an optional add-on.
We bump no-heat calls ahead of routine work when temperatures drop, especially in peak winter.
You approve a fixed repair price before any part is replaced, whether it's an ignitor or a heat exchanger.
Whether the furnace runs on gas or electric heat strips, our techs are trained on both, so the fuel type never determines who gets sent.
The most common furnace failure points.
A cracked hot-surface ignitor or a flame sensor coated in carbon buildup are two of the most common no-heat causes, and both are usually same-visit fixes.
Gas valve testing means checking actual response and pressure output, since these parts are costly enough to warrant confirming the fault first.
A cracked heat exchanger is a genuine safety issue that can leak combustion gases into the airflow — we inspect with a camera and combustion analyzer rather than assuming based on age alone.
Short-cycling or mid-cycle shutdowns frequently trace back to the limit switch or a struggling blower motor — we test both before condemning the control board.
We still service standing-pilot furnaces, checking thermocouple output and draft conditions that newer ignition systems don't have.
Zero response from the furnace can mean a wiring fault or thermostat issue rather than the furnace itself — we rule this out early to avoid overcharging for parts you don't need.
What happens from your call to heat restored.
Tell us what the furnace is doing and we'll route the closest technician.
Truck arrives stocked with common ignitor, flame sensor, and control board parts ready to diagnose and often repair on the spot.
We run the safety and diagnostic checks first, then present a flat-rate quote for your approval.
Repairs typically wrap same visit, and we re-check CO levels before signing off, backed by our labor warranty.
Feedback from completed furnace repairs.
Furnace kept shutting off every twenty minutes. The tech found a dirty flame sensor and cleaned it, been running fine for two months now.
— B. Halloran, homeowner
They caught a hairline crack in the heat exchanger during a routine repair call and walked me through the safety concern honestly, not to upsell.
— V. Ashworth, homeowner
No heat during the coldest week of the year, they got someone out same day and had it fixed within an hour, ignitor replacement.
— Q. Delrio, homeowner
Old standing pilot furnace that most companies don't want to touch anymore. They knew exactly what they were doing, thermocouple was the issue.
— E. Vantassel, homeowner
What O Fallon customers ask most.
Clicking or humming without ignition often points to the ignitor, though we always confirm with a proper resistance reading before quoting.
It's a genuine safety concern since it can let combustion byproducts into the airflow, so we take the inspection seriously and won't operate a confirmed-cracked unit.
Every furnace call includes a CO check with a combustion analyzer, no extra charge.
Yes — our techs are trained on thermocouples, pilot orifices, and draft diagnostics for older systems, including thermocouple and draft-related repairs.
No-heat calls get priority routing, typically same-day during winter demand even during high-demand cold weather.
Most common parts — ignitors, flame sensors, control boards — are stocked, but rare parts may need next-day ordering to complete the repair.
We dispatch heating techs throughout O Fallon and the surrounding zips — call to confirm availability.
Call +1-844-611-2875
