Universal furnace flame sensor
Clean first, then match rod length and connector style before replacing flame-sense faults.
$8-$35
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Furnace Error Code Lookup — Start Here
Furnace fault codes are usually shown as blinking LEDs, two-digit board codes, or thermostat alerts. This page is your fast lookup hub for the most common furnace brands and the faults technicians see most often: pressure switch issues, limit trips, ignition failures, flame sensing, blower faults, and rollout safety trips.
Common Furnace Fault Patterns
| Fault Type | What It Usually Means |
|---|---|
| Pressure switch open | Inducer draft problem, blocked vent, condensate issue |
| Limit switch open | Overheating from airflow restriction |
| Ignition lockout | Gas, igniter, or flame sensor problem |
| Flame sense fault | Dirty flame sensor or bad grounding |
| Blower fault | PSC capacitor, ECM module, or airflow issue |
| Rollout switch open | Serious combustion problem, stop and inspect |
Brand Hubs Covered
- Carrier and Bryant
- Goodman and Amana
- Lennox
- Trane and American Standard
- York and Coleman
- Heil, Tempstar, Comfortmaker, ICP brands
- Rheem and Ruud
Step-by-Step Fix
- Read the exact flash count or code.
- Check the filter and airflow first — This solves a surprising number of limit faults.
- Watch the ignition sequence — Inducer, igniter, gas valve, flame prove.
- Clean the flame sensor before replacing expensive parts.
- Treat rollout faults as safety faults, not nuisance codes.
Parts Often Needed
| Part | Notes |
|---|---|
| Flame sensor | Cheap and commonly dirty |
| Hot surface igniter | Fragile, common wear part |
| Pressure switch | Check tubing before replacing |
| Blower capacitor | Common on PSC motor furnaces |
| Air filter | Low-cost first fix |
Technician Tips
Use the lookup result as a starting point, then confirm the brand, model number, and exact blink pattern before ordering anything. The same flash count can mean different circuits on different furnace boards.
Parts note: Common furnace-code repairs include flame sensors, hot-surface igniters, pressure switches, limit switches, rollout switches, blower capacitors, inducer assemblies, and control boards. Match parts to the furnace model and board revision, not just the error code.
Need Replacement Parts?
Before ordering, match the furnace part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If the code points to rollout, heat exchanger concerns, gas valve issues, or persistent lockouts after basic cleaning and filter replacement, call a licensed HVAC technician. Some furnace faults are safety issues, not DIY maintenance items.