Furnace error codes (page 2)
178 documented codes across brands, with ranked causes and repair costs.
Rheem furnace code chart (13) York furnace code chart (21) Goodman furnace code chart (24) Lennox furnace code chart (34) Trane furnace code chart (23) Carrier furnace code chart (30) Amana furnace code chart (9) American Standard furnace code chart (8) Bryant furnace code chart (16)
York Furnace — Flame sensor problems York Furnace Flame Sensor Problems: Causes & Fixes York furnace flame sensor problems cause short cycling and ignition lockout. Learn the causes, fixes and repair costs ($80 diagnostic – $800+ with a board). York Furnace — Keeps shutting off York Furnace Keeps Shutting Off: Causes & Fixes York furnace keeps shutting off? Flame sensor, limit, pressure switch & flue causes, safe DIY checks, and repair costs from $0 to $1,200. York Furnace — Loud bang on startup York Furnace Loud Bang on Startup: Causes & Fixes A loud bang when your York furnace starts usually means delayed ignition or expanding ductwork. Causes, fixes and repair costs explained. York Furnace — Short cycling York Furnace Short Cycling: Causes, Diagnosis & Fixes York furnace short cycling? Causes range from a clogged filter to a failing flame sensor or limit. DIY checks plus repair costs $0-$2,500+. York Furnace — Won't turn on York Furnace Won't Turn On: Causes, Fixes & Costs York furnace won't turn on? Causes from no power, dead thermostat, blown fuse or bad door switch, plus fixes and repair costs from $0 DIY to $1,100. Lennox Furnace — Blower not running Lennox Furnace Blower Not Running: Causes & Fixes Lennox furnace blower not running? Causes include a bad capacitor, blower motor, control board or door switch, plus fixes and US repair costs. Lennox Furnace — Clicking but not starting Lennox Furnace Clicking But Not Starting: Causes & Fixes Lennox furnace clicking but not starting? Causes include a stuck pressure switch, weak igniter, dirty flame sensor or open safety. Fixes and $0–$1,200 costs. Lennox Furnace — Blower won't shut off Lennox Furnace Blower Won't Shut Off: Causes & Fixes Lennox furnace blower runs constantly? Causes include thermostat fan settings, an open limit switch, or a stuck relay. DIY checks plus $0–$1,200 repair costs. Lennox Furnace — Flame sensor problems Lennox Furnace Flame Sensor Problems: Fixes & Costs Lennox furnace flame sensor problems cause dropouts and lockouts from a dirty or failed sensor. Cleaning runs $80-$180; replacement $150-$300. Lennox Furnace — Ignition lockout Lennox Furnace Ignition Lockout: Causes, Fixes & Costs Lennox furnace ignition lockout causes—igniter, flame sensor, gas supply, pressure switch—plus safe checks, tech diagnosis, and repair costs from $0 to $1,200. Lennox Furnace — Keeps shutting off Lennox Furnace Keeps Shutting Off: Causes, Fixes & Costs Lennox furnace keeps shutting off? Causes include dirty filters, flame sensor, limit and pressure switch faults — fixes and US repair costs. Lennox Furnace — Leaking water Lennox Furnace Leaking Water: Causes, Fixes & Costs Lennox furnace leaking water? Causes include clogged condensate drains, cracked traps and flue issues, plus fixes and honest US repair costs. Lennox Furnace — Loud bang on startup Lennox Furnace Loud Bang on Startup: Causes & Fixes A loud bang when your Lennox furnace ignites usually means delayed ignition or duct oil-canning. Safety steps first, then causes, checks, fixes and costs. Lennox Furnace — Short cycling Lennox Furnace Short Cycling: Causes, Fixes & Costs Lennox furnace short cycling? Common causes include dirty filters, overheating limits, flame sensor issues and oversizing—with fixes and US cost ranges. Lennox Furnace — Won't turn on Lennox Furnace Won't Turn On: Causes, Fixes & Costs Lennox furnace won't turn on? Common causes from thermostat and power to blown fuses and failed boards, with DIY checks and honest US repair costs. Trane Furnace — Leaking water Trane Furnace Leaking Water: Causes, Fixes & Costs Trane furnace leaking water is usually a clogged condensate drain, bad trap, or cracked inducer. See causes, safe checks, fixes & real US costs. Trane Furnace — Pressure switch stuck open Trane Furnace Pressure Switch Stuck Open: Causes & Fixes Trane furnace pressure switch stuck open: causes from blocked vents to a failing inducer, safe checks, and repair costs from $0 DIY to $1,200. Goodman Furnace — Blower not running Goodman Furnace Blower Not Running: Causes & Fixes Goodman furnace blower not running? Causes from a bad blower motor, capacitor, or control board, plus DIY checks, repairs and honest cost ranges. Goodman Furnace — Flame sensor problems Goodman Furnace Flame Sensor Problems: Fixes & Costs Goodman furnace flame sensor problems cause weak flame signal and short cycling. Causes, cleaning, and repair costs from $0 to $1,200. Goodman Furnace — Pressure switch stuck open Goodman Furnace Pressure Switch Stuck Open: Fixes Goodman furnace pressure switch stuck open? Causes include blocked vent, bad inducer, condensate clogs. Fixes and costs from $0 DIY to $1,200. Trane Furnace — Blower not running Trane Furnace Blower Not Running: Causes & Fixes Trane furnace blower not running? Causes from door switches to bad capacitors or blower motors, DIY checks, and honest repair costs. Trane Furnace — Blower won't shut off Trane Furnace Blower Won't Shut Off: Causes & Fixes Trane furnace blower runs constantly? Causes include thermostat fan settings, a stuck limit switch or bad control board, plus fixes and repair costs. Trane Furnace — Clicking but not starting Trane Furnace Clicking But Not Starting: Causes & Fixes Trane furnace clicking but not starting? Causes include a failing ignition relay, weak transformer, or draft inducer. Fixes and costs from $0 DIY to $600. Trane Furnace — Flame sensor problems Trane Furnace Flame Sensor Problems: Causes & Fixes Trane furnace flame sensor problems cause short cycling and lockouts. Causes, safe homeowner checks, how a technician diagnoses it, and real repair costs.