A reliable furnace keeps your home warm when chilly winds blow outside. Unexpected breakdowns in winter can leave you scrambling for repair help on the coldest days. At Swiss Air Heating & Cooling, LLC, in O’Fallon, MO, we’ve seen every furnace problem imaginable and help homeowners avoid those pitfalls with timely service.
Weak or Flickering Pilot Light
When your furnace’s pilot light burns low or flickers out, it can leave your home shivering on a cold morning. You might notice an orange flame instead of a steady blue one, or the furnace may keep shutting off without warming the air. These symptoms often point to a dirty thermocouple or a clogged pilot orifice. A qualified HVAC technician uses specialized tools to clean the pilot assembly and test the thermocouple’s voltage output.
If the sensor no longer detects heat reliably, they replace it with a factory-approved part. After those adjustments, your pilot light reignites with a firm blue glow that remains stable, ensuring the burner can fire up whenever the thermostat calls for heat.
Uneven Heat Distribution
You expect every room to feel cozy, but sometimes bedrooms stay chill while living areas grow toasty. Uneven heating can stem from blocked vents, imbalanced ductwork, or an undersized blower motor. A trained professional inspects grille registers and duct branches, measuring airflow at each outlet. They’ll adjust damper settings in the duct system to reroute warm air where it’s needed most. If the blower lacks the power to push air through longer runs, the technician may recommend upgrading to a higher-capacity motor or adding a supplementary inline fan.
Strange Noises During Startup
A healthy furnace greets the heating call with a brief click and a smooth whoosh of the blower. If you hear squeals, rattles, or clanks, something needs attention. Squealing often signals worn blower bearings or a stretched belt, which a pro can lubricate or replace. Rattles may come from loose heat exchanger panels or mounting brackets, which can be tightened quickly by a service technician.
Short Cycling and Frequent On-Off Runs
When your furnace switches on and off every few minutes, it struggles to complete a full heat cycle. Short cycling stresses the compressor or heat exchanger and drives up energy bills. Common causes include a dirty air filter, restricted airflow, or a miscalibrated thermostat. A service call starts with a filter check; if it’s clogged, your technician will install the correct replacement. Next, they measure static pressure in the duct system and clear any blockages. If the thermostat reads room temperature inaccurately, the pro recalibrates or replaces it with a compatible control.
Malfunctioning Safety Switches
Safety switches detect dangerous conditions and shut off the furnace to protect your home. If a limit switch trips too soon or a flame rollout sensor opens unexpectedly, the unit will refuse to run. Diagnosing that issue involves a step-by-step inspection of sensors and wiring by a licensed technician. They test each switch’s activation temperature and clean or replace the component if it fails to close and open correctly. A functional safety system lets your furnace manage high heat loads without unnecessary shutdowns, while still interrupting operation in the rare event of a real hazard.
Thermostat Communication Errors
Modern furnaces often connect to programmable or smart thermostats. When the furnace ignores temperature commands or displays error codes, the problem might lie in miswired terminals or firmware glitches. A trained HVAC professional traces the wiring harness back to the control board, confirming tight connections and reading live voltage levels. If the control board shows a stored error, they follow manufacturer procedures to clear codes and update software. Technicians can also advise on thermostat placement, moving it away from drafts, direct sunlight, or heat-emitting appliances to prevent misleading room readings.
Frozen or Blocked Condensate Drain
High-efficiency furnaces generate water as they extract heat, and that condensate flows through a drain line into your home’s plumbing. In winter, that line can freeze or clog with algae, causing backup and a system shutdown. An HVAC expert locates the drain, uses a wet-dry vacuum to clear blockages, and then applies an approved clearing solution to dissolve any biofilm. If the pipe freezes, your technician installs heat cable rated for condensate lines, preventing ice dams during cold spells. Once the line flows freely, your furnace operates without dripping water inside the cabinet.
Gas Pressure and Venting Checks
When you suspect inconsistent flame quality or smell faint exhaust fumes, it’s time for a gas pressure and venting inspection. A professional gauges inlet and manifold pressures, adjusting the gas valve to the manufacturer’s specifications. They also examine vent pipes for corrosion, proper slope, and secure joints. Clearance to combustible materials is verified with a measuring gauge. After wrapping up, the technician lights the burners and observes the flame pattern, tall and vibrant blue, ensuring combustion remains efficient and safe throughout winter.
Keep Your Furnace in Top Shape All Season
Dealing with furnace issues early prevents sudden failures and expensive emergency repairs. Along with addressing pilot light troubles and airflow imbalances, Swiss Air Heating & Cooling, LLC offers comprehensive safety checks and annual maintenance plans to keep your heating system humming. We also handle thermostat upgrades and high-efficiency system tune-ups tailored to your home’s needs. Ready to keep winter’s chill at bay? Schedule your expert furnace inspection with Swiss Air Heating & Cooling, LLC today.
