Furnace Parts

Common Furnace Parts That Fail

When your furnace stops heating, one of a handful of high-wear parts is almost always the culprit. Hot surface igniters, draft inducer motors, pressure switches, and flame sensors account for the vast majority of furnace repairs — and they're all affordable, replaceable parts. Repair Clinic stocks genuine OEM parts for, and all major furnace brands.

Whether your furnace won't ignite, shuts off mid-cycle, or the blower won't run, finding your model number is the fastest path to the exact part you need. We carry the same OEM parts your furnace installer stocks — at competitive prices with same-day shipping on most in-stock items.

• Hot surface igniter glows orange then dies, or won't glow at all: Replace the igniter (silicon carbide or silicon nitride — verify type for your model)
• Furnace starts then shuts down within seconds: Flame sensor failure is the #1 cause (try cleaning with fine steel wool first)
• Pressure switch keeps tripping or furnace won't start: Check for blocked drain lines or cracked hose; if clear, the pressure switch has likely failed
• No airflow from vents, or blower runs constantly: Blower motor or capacitor failure; capacitor is often the cheaper fix
• Inducer motor making noise or furnace cycling on/off randomly: Draft inducer assembly needs replacement; verify motor HP and flange type

Furnace Parts & Repairs: Your Questions Answered

What's the difference between a silicon carbide and silicon nitride igniter?

Both are hot surface igniters, but they have different resistance ratings and are not interchangeable. Silicon carbide (SiC) igniters are flat and more common in older furnaces (, ). Silicon nitride (SiN) igniters are curved and used in newer models, particularly and some units. Always confirm your furnace's igniter type before ordering — using the wrong type will prevent the gas valve from opening. Your furnace's model number or the part number on the old igniter will tell you which type is correct.

How do I know if my furnace pressure switch is the problem?

A tripped pressure switch is often a symptom of a larger issue — a blocked furnace drain line, kinked hose, or failing draft inducer motor. Before replacing the switch, check that the condensate drain is clear and the hose connection is tight. If those are fine and the switch still won't reset, or if it trips every heating cycle, the switch itself has failed. Pressure switches are inexpensive ($15 to $30) and a quick swap, but ruling out airflow blockage first saves you from replacing the switch only to have the same problem return.

Why does my or furnace have error codes, and how do I find the control board?

Modern Infinity and XC95m furnaces use communicating control boards (IFC or CNT boards) that display error codes via LED blinks or a digital display. Count the flashes or check your owner's manual to decode the message — it usually points to the igniter, flame sensor, pressure switch, or the board itself. Control boards are model-specific and must be OEM; aftermarket boards will not work with communicating furnaces. Enter your exact furnace model number in our search to find the correct board pre-programmed for your system.

What's the most common reason a furnace blower runs constantly without heating?

A blower that runs but produces no heat usually points to the igniter, flame sensor, or a faulty limit switch. However, a blower that runs non-stop (even during cooling season or when the thermostat is off) often indicates a failed limit switch or control board. The limit switch is a safety device that tells the blower when to run — if it fails in the "on" position, the blower never stops. It's a $20 to $40 part and one of the simpler furnace repairs. If the limit switch tests fine, the main control board may need replacement.

Order Furnace Replacement Parts Online

Finding the right furnace replacement parts is easy with Repair Clinic. Whether you need a blower motor, gas valve, flame sensor, or air filter, our vast inventory ensures you get the exact part for your furnace model. Search by model or part number for fast, accurate results.

With 365-Day No-Hassle Returns and our Price Match Guarantee, you can shop confidently, knowing you're getting competitive pricing on genuine OEM furnace parts. Plus, with same-day shipping on orders placed by 9:00 PM ET, you can get your furnace back to reliable operation quickly. Whether you're a DIY homeowner or an HVAC professional, Repair Clinic has the parts and support you need for a reliable repair.

Filter Furnace Parts by Your Model Number

Check the blower compartment door, inside the front access panel, or near the gas valve for your furnace's model label. The label may list several numbers, so look specifically for "model" or "M/N" rather than the serial number. Enter that model number in the search bar to filter the full furnace parts catalog to parts that fit your unit. If the label is dusty or hard to read, use a flashlight and record every letter, number, and slash exactly as shown. A precise lookup cuts down compatibility checks and helps you get the repair moving without a wrong order.