The first hard freeze settles over Berne Township and your furnace struggles to keep pace. Rooms farthest from the unit stay several degrees cooler than the thermostat setting. The blower runs longer than it did last winter. You smell a faint burning odor during the first few cycles. These conditions appear when a furnace has gone a full season without a furnace tune-up. Dust, oxidation, and minor wear reduce heat transfer and airflow. A timely furnace service visit restores the unit before the coldest weeks arrive.
Stage 1: Arrival, Isolation, and Initial Safety Survey
We begin every furnace tune-up by confirming the thermostat call for heat and recording the current supply and return temperatures. Next we shut off electrical power at the service switch and gas supply at the appliance valve. This isolation prevents accidental ignition while we work. We then examine the furnace cabinet, vent connector, and surrounding area for rust, soot, or water stains that signal past condensation or combustion problems. The heat exchanger receives a close visual check with a bright inspection light and a mirror to locate cracks or corrosion that could allow flue gases into the living space.
We test the draft hood or inducer for proper venting. A blocked or disconnected flue pipe can send carbon monoxide back into the home. We also verify that the furnace has adequate combustion air. Tight modern construction sometimes starves the burner of oxygen and produces incomplete combustion. If we find a cracked heat exchanger or a severely restricted vent, we stop the tune-up and explain the safety issue immediately. Our expert technicians remain available 24/7, so we can return the same day if a follow-up repair is required. Free estimates accompany any recommended work.
Stage 2: Cleaning Burners, Heat Exchanger, and Air-Moving Components
Dirty burners cause yellow tipping, lifting flames, and delayed ignition. We remove the burner assembly, brush each port, and vacuum loose scale. On inshot burners we also clean the crossover ports so the flame travels evenly from one end to the other. After reassembly we observe the ignition sequence and adjust the gas manifold pressure to the manufacturer specification, usually between 3.2 and 3.8 inches of water column for natural gas. Correct pressure produces a sharp blue flame that sits correctly on the burner face.
The heat exchanger surfaces collect soot and mineral deposits that insulate the metal and reduce heat transfer. We brush accessible passages and vacuum debris. On high-efficiency condensing furnaces we also flush the secondary heat exchanger and condensate trap so acidic water drains freely. A clogged trap can shut the furnace down on a pressure-switch fault. We then turn attention to the blower. We remove the blower wheel, clean accumulated dust from the blades, and check the motor bearings. A dirty wheel unbalances the assembly and overloads the motor. If the motor uses oil ports we apply the specified lubricant. Direct-drive motors receive a current draw test to confirm they operate within nameplate amperage.
- Flame sensor – We remove the rod, polish the metal surface, and measure the microamp signal during operation. A weak signal below 1.5 microamps causes nuisance lockouts.
- Igniter – We inspect silicon-carbide or hot-surface igniters for cracks and measure resistance. We replace any igniter that shows signs of fatigue before it fails on a cold morning.
- Limit and rollout switches – We test each safety control for correct opening temperature and continuity. A limit that opens too soon produces short-cycling.
Stage 3: Airflow, Filter, and Duct Evaluation
Restricted airflow is the most common cause of overheating and reduced comfort. We measure static pressure on both sides of the blower and compare the reading to the furnace rating plate. High external static pressure indicates undersized returns, dirty coils, or closed dampers. We replace the disposable filter with the correct MERV rating and size so the new filter does not add excessive resistance. We also inspect the filter rack for bypass gaps that allow unfiltered air to coat the blower and heat exchanger.
We check the supply and return plenums for leaks at the furnace connection. Even small gaps waste heated air into the basement or crawl space. On systems with an evaporator coil we inspect the coil face for dirt that restricts airflow in heating mode. A dirty coil can raise the temperature rise above the allowable range and trip the high-limit switch. We record the temperature rise after the furnace has operated for ten minutes. The rise must fall inside the range printed on the rating plate, typically 30 to 60 degrees Fahrenheit. A rise that is too high or too low tells us the gas input or the airflow needs further adjustment.
Stage 4: Combustion Analysis, Electrical Checks, and Final Verification
We connect a combustion analyzer to the flue and record oxygen, carbon dioxide, carbon monoxide, and stack temperature. These numbers confirm that the air-fuel mixture is correct and that the heat exchanger transfers heat efficiently. Elevated carbon monoxide or low carbon dioxide indicates a need for further burner or heat-exchanger work. We also measure the temperature of the vent connector to verify that the flue gases stay hot enough to maintain draft yet cool enough to protect PVC venting on condensing units.
Electrical connections receive a torque check and a visual inspection for discoloration. Loose lugs create heat and voltage drop that can damage the control board or inducer motor. We test the thermostat wiring for correct 24-volt signals and confirm that the anticipator or cycle-rate setting matches the furnace. After all adjustments we restore power and gas, then run the furnace through a complete heating cycle. We watch ignition, flame quality, blower start delay, and shutdown sequence. Only when every parameter meets specification do we consider the furnace tune-up complete.
- Record baseline data – We note gas pressure, temperature rise, and combustion readings so you have a reference for next season.
- Review findings – We explain any items that need attention and provide a written summary of the work performed.
- Schedule follow-up if needed – If a part shows wear we can return with the correct component the same day because we keep common furnace parts on the truck.
What Regular Furnace Maintenance Delivers Through the Heating Season
A completed furnace tune-up lowers the chance of a no-heat call on the coldest night of the year. Clean burners and a free-flowing heat exchanger produce more heat from the same cubic feet of gas. The blower moves the designed volume of air so every room reaches the set temperature without long run times. Safety controls operate at their intended set points, which protects the heat exchanger from overheating and reduces the risk of carbon monoxide production. Manufacturers require annual furnace maintenance to keep the warranty in force. Skipping the visit can void coverage on a heat exchanger or control board that fails later.
Berne Township winters place heavy demand on heating equipment. A furnace that receives yearly furnace service lasts longer and uses less energy. We provide comprehensive HVAC solutions, from installation and repair to maintenance and energy-efficient upgrades, ensuring your comfort and peace of mind. As a hometown company that is family-owned and women-owned, Hubbs Heating & Air knows the local housing stock and the weather patterns that stress furnaces. Our technicians carry the tools and meters needed to complete a thorough furnace tune-up on the first visit. Choose us for efficient, hassle-free service that keeps your home or business running smoothly. Whether the unit is a 20-year-old natural-draft furnace or a new modulating condensing model, the same systematic process restores reliable heat before the next freeze arrives.