Annual Furnace Maintenance for Greater Houston Homes

Our technician arrives and begins with a thorough visual inspection of the entire furnace:

• Cabinet and Housing — We check for rust, corrosion, moisture stains, cracks, or physical damage. Rust signals moisture intrusion (condensation issue). Cracks or visible damage can affect safe operation.
• Gas Connections and Lines — We inspect all gas line fittings, connections, and tubing for corrosion, damage, or loose connections. Corroded fittings can leak; loose connections can introduce air into the gas line, causing incomplete combustion.
• Electrical Connections and Control Board — We examine the control board for corrosion, burnt marks, or loose wiring. We verify that all electrical connections are tight and properly seated.
• Exhaust Venting — We check the flue pipe or vent connection for cracks, blockages, corrosion, or improper installation. A blocked or leaking vent is a serious safety issue.
• Blower Compartment and Motor — We look at the blower assembly for dust accumulation, bearing condition, and motor mounting. Excessive dust restricts airflow; worn bearings make noise and eventually fail.

If we spot any concerns during visual inspection, we note them for detailed testing later.

A clean air filter is critical for airflow, efficiency, and furnace lifespan. We check your current filter:

• Filter Condition — Is it clean or clogged with dust and debris? A severely clogged filter restricts airflow, reduces heating capacity, and forces the furnace to work harder and cycle more frequently.
• Filter Type and Fit — Is it the correct size and type for your furnace? Some filters are 1-inch thick (basic); others are 4-5 inches (high-MERV filters for better dust capture). Wrong-size filters bypass dust and don’t function properly.
• Replacement if Needed — If the filter is clogged or overdue, we replace it with the correct size and efficiency grade. A clean filter is the single easiest way to maintain furnace performance.

We discuss filter-change frequency: most homes need new filters every 1–3 months depending on household dust, pet dander, and filter type. We provide guidance so you can maintain clean airflow between service visits.

The thermostat controls when your furnace runs. An inaccurate thermostat causes short-cycling, failure to reach setpoint, or continuous operation. We test:

• Temperature Accuracy — We place a calibrated reference thermometer near the thermostat and compare its reading to the thermostat’s display. If readings differ by more than 1–2°F, the thermostat is drifting out of calibration.
• Heating Signal — We set the thermostat slightly above room temperature to confirm it properly calls for heat. We observe whether the furnace responds immediately or with a delay, which indicates proper or problematic wiring.
• Display and Controls — On digital thermostats, we verify the display is clear, buttons are responsive, and the unit is powering properly. On programmable/smart thermostats, we confirm the schedule is set correctly and the unit is responding to commands.

If the thermostat is drifting out of calibration or showing age, we discuss replacement options. A modern programmable or smart thermostat can significantly improve comfort and energy efficiency.

The ignition system lights the furnace’s burner. Without reliable ignition, your furnace won’t heat. We test:

• Hot Surface Igniter (Modern Furnaces) — We observe the igniter element during startup. Does it glow when the control board calls for heat? We measure the glow temperature to confirm it’s hot enough to ignite gas. A weak or non-glowing igniter is near failure and should be replaced proactively.
• Spark Ignition System — On some furnaces, a spark plug ignites gas instead of a hot surface igniter. We verify that spark is present when called and that the spark is consistent and strong.
• Pilot Light (Older Furnaces) — On furnaces with standing pilot lights, we verify the pilot is burning steadily and that the thermocouple (safety device that confirms the pilot is lit) is responding correctly.

An aging igniter often fails during cold snaps when your furnace runs continuously. Replacing it during maintenance prevents mid-winter failure.

Proper combustion depends on clean burner surfaces, correct gas pressure, and adequate air supply. We test:

• Burner Condition — We visually inspect the burner assembly for rust, corrosion, or carbon buildup. Rust and corrosion reduce gas flow efficiency; carbon deposits need careful cleaning.
• Burner Flame Quality — When we call for heat, we observe the burner flame. A healthy furnace produces a blue flame, indicating complete combustion. An orange or yellow flame suggests incomplete combustion (possible air shortage or dirty burner) or safety concerns.
• Gas Pressure — We connect a manometer (pressure gauge) to measure gas pressure at the furnace inlet. Natural gas furnaces operate at 3.5–4 inches of water column pressure. Pressure that’s too low (utility issue or regulator failure) or too high (gas control valve problem) affects heating performance and safety.

If combustion shows any irregularities—wrong flame color, incorrect pressure, or visible corrosion—we clean the burner, verify gas supply, or recommend component replacement.

The heat exchanger transfers heat from combustion into your home’s air. A cracked heat exchanger is dangerous (allows carbon monoxide to escape into your home). We inspect:

• Visual Inspection for Cracks or Corrosion — We look for visible cracks, holes, or severe corrosion on the heat exchanger surfaces. We also check for signs of past leaking (rust discoloration, corrosion patterns) that might indicate hairline cracks.
• Heat Transfer Verification — We verify that warm air is properly flowing from the heat exchanger into your ductwork. If the exchanger is blocked with dust or rust, heat transfer is poor and heating performance suffers.

If we detect or suspect a cracked heat exchanger, we immediately stop the furnace and recommend replacement. A cracked exchanger cannot be safely repaired—replacement is the only safe solution.

The blower motor circulates warm air throughout your home. A failing blower means reduced heating. We test:

• Blower Motor Startup — When the furnace calls for heat, does the blower motor start immediately or with a delay? Delayed startup suggests a failing capacitor (common wear item) or motor bearing issues.
• Blower Noise and Vibration — We listen and feel the blower assembly. Squealing indicates bearing wear; grinding indicates imminent motor failure. Rattling suggests loose components inside the unit.
• Airflow Through Ducts — We feel warm air at return and supply vents. Strong, even airflow indicates healthy blower performance. Weak or uneven airflow suggests blower motor fatigue, belt slippage (on older units), or duct blockages.

If the blower is making noise or producing weak airflow, motor replacement during maintenance prevents winter breakdown.

Furnaces have safety switches that shut down the system if dangerous conditions develop. We verify they’re functioning:

• Limit Switch — This switch prevents the furnace from overheating. If heat builds up beyond a safe threshold, the limit switch trips and stops the burner. We confirm the switch responds properly to temperature changes.
• Rollout Switch — This switch detects flames escaping the combustion chamber (indicating a venting problem) and shuts down the furnace. A properly functioning rollout switch is essential for safety.
• Gas Valve Solenoid — We verify the gas valve solenoid (the electromagnet that opens the gas valve when called) is responsive and closing properly after the heating cycle ends.

If switches are stuck, sluggish, or non-responsive, we recommend replacement to maintain safety integrity.

Safety testing is mandatory on every maintenance visit. We perform:

• Carbon Monoxide Testing — We place CO detectors in the furnace area and throughout your home. We run the furnace under load for a full heating cycle and monitor for any CO leaks. A properly maintained furnace produces zero detectable carbon monoxide. If we find any CO, we immediately identify the source (usually a venting problem) and address it.
• Gas Leak Detection — We use a sensitive gas detector to inspect all gas line connections, the furnace inlet, and the gas valve. Any leaks are immediately tagged and repaired.
• Backdraft Testing — We verify that the furnace venting doesn’t create negative pressure in your home, which could pull dangerous gases back inside.

All test results are documented and provided to you.

We verify warm air distribution throughout your home:

• Ductwork Inspection — We visually check accessible ductwork for leaks, blockages, or disconnections. A well-sealed duct system ensures your furnace heating reaches all areas of your home efficiently.
• Airflow Balance — We check that warm air flows evenly to all rooms. If some rooms are significantly warmer or colder than others, we may identify damper adjustments or duct issues that need attention.

If ductwork needs sealing, insulation, or cleaning, we discuss options and provide recommendations.

Before we leave, we provide a comprehensive written report documenting:

• All Test Results — Gas pressure readings, combustion testing, CO testing, thermostat accuracy, blower performance, safety switch verification.
• Any Issues Found — Components that are functioning normally, components showing early wear (worth watching), and components that need replacement soon or immediately.
• Maintenance Recommendations — Specific actions you can take to maintain your furnace between professional visits (filter changes, clearing obstructions, monitoring for unusual sounds or smells).
• Equipment Lifespan and Repair Economics — If your furnace is aging (12+ years), we discuss typical remaining lifespan and when replacement might become economical.

We answer all your questions and discuss any concerns about your furnace’s condition. If you have questions between visits, you have a documented baseline to reference.