Furnace error codes
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)
Rheem Furnace — Clicking but not starting Rheem Furnace Clicking But Not Starting: Causes & Fixes Rheem furnace clicking but not starting? Causes include a bad igniter, relay, inducer, control board or transformer. Fixes and costs: $0 DIY to $1,200+. Rheem Furnace — Leaking water Rheem Furnace Leaking Water: Causes, Fixes & Costs Why a Rheem furnace leaks water: clogged condensate drain, failed pump, AC coil pan, venting issues. Safe checks, pro fixes, and costs from $0 to $2,500+. Rheem Furnace — Pressure switch stuck open Rheem Furnace Pressure Switch Stuck Open: Causes & Fixes Rheem furnace pressure switch stuck open: blocked vents, condensate, or a weak inducer, safe checks, and repair costs from $0 to $1,200 or more. Rheem Furnace — Runs constantly but not enough heat Rheem Furnace Runs Constantly, Not Enough Heat: Fixes Rheem furnace runs nonstop but the house stays cool? Learn the likely causes, safe homeowner checks, what a tech will test, and typical repair costs. York Furnace — Pressure switch stuck open York Furnace Pressure Switch Stuck Open: Causes & Fixes York furnace pressure switch stuck open: blocked vents, condensate, or a weak inducer. Diagnosis, fixes and $0 DIY to $1,200+ repair costs. Rheem Furnace — Blower not running Rheem Furnace Blower Not Running: Causes & Fixes Rheem furnace blower not running? Causes include door switch, board fuse, blower capacitor, motor and control board — plus safe DIY checks and repair costs. Rheem Furnace — Blowing cold air Rheem Furnace Blowing Cold Air: Causes & Fixes Rheem furnace blowing cold air? Common causes like thermostat fan settings, flame sensor failure or limit lockout, plus fixes and repair costs. Rheem Furnace — Flame sensor problems Rheem Furnace Flame Sensor Problems: Causes & Fixes Rheem furnace flame sensor problems cause short cycling and lockouts. Common causes, safe homeowner checks, pro cleaning and typical costs of $80–$250. Rheem Furnace — Ignition lockout Rheem Furnace Ignition Lockout: Causes, Fixes & Costs Rheem furnace ignition lockout means failed trial-for-ignition after multiple tries. Causes, safe checks, and $0 DIY to about $1,550 repair costs. Rheem Furnace — Keeps shutting off Rheem Furnace Keeps Shutting Off: Causes & Fixes Rheem furnace keeps shutting off? Common causes include overheating, flame sensor, pressure switch and limit faults — fixes and costs from $0 to $3,500+. Rheem Furnace — Loud bang on startup Rheem Furnace Loud Bang on Startup: Causes & Fixes Rheem furnace loud bang on startup usually means delayed ignition or expanding ductwork. Causes, fixes and costs from $0 DIY to $900. Rheem Furnace — Short cycling Rheem Furnace Short Cycling: Causes, Fixes & Costs Rheem furnace short cycling? Causes include dirty filters, overheating limits, oversizing and flame-sensor faults — fixes and costs from $0 to $1,800. Rheem Furnace — Won't turn on Rheem Furnace Won't Turn On: Causes, Fixes & Costs Rheem furnace won't turn on? Causes from tripped breakers to failed boards, safe checks you can do, plus honest US repair costs. York Furnace — Leaking water York Furnace Leaking Water: Causes, Fixes & Costs York furnace leaking water? Common causes include clogged condensate drains, cracked traps and flue issues—plus DIY checks and real US repair costs. York Furnace — Runs constantly but not enough heat York Furnace Runs Constantly But Not Enough Heat: Fixes York furnace runs nonstop but won't warm your home? Causes include dirty filters, duct losses, staging faults & heat exchanger problems. Fixes $0 DIY–$3,500+. Goodman Furnace — Runs constantly but not enough heat Goodman Furnace Runs Constantly But Not Enough Heat Goodman furnace running nonstop but can't warm the house? Causes from dirty filters to failing heat exchangers, plus DIY checks and repair costs. Lennox Furnace — Pressure switch stuck open Lennox Furnace Pressure Switch Stuck Open: Fixes & Cost Lennox furnace pressure switch stuck open: causes from blocked vents to a failing inducer, safe DIY checks, pro fixes, and real US repair costs. Lennox Furnace — Runs constantly but not enough heat Lennox Furnace Runs Constantly But Not Enough Heat Lennox furnace runs nonstop but can't keep up: dirty filter, undersized ducts, flame issues & more. DIY checks, pro fixes, and costs from $0 to $3,500+. Lennox Furnace — Won't ignite Lennox Furnace Won't Ignite: Causes, Fixes & Costs Lennox furnace won't ignite? Causes include a failed igniter, dirty flame sensor, closed gas valve and pressure switch faults — fixes and costs inside. Trane Furnace — Runs constantly but not enough heat Trane Furnace Runs Constantly But Not Enough Heat Trane furnace runs nonstop but can't keep up? Causes from dirty filters to failing heat exchangers, DIY checks, fixes and honest US repair costs. York Furnace — Blower not running York Furnace Blower Not Running: Causes & Fixes York furnace blower not running? Causes from blower motor to control board, plus DIY checks and repair costs from $0 to $1,500+. York Furnace — Blower won't shut off York Furnace Blower Won't Shut Off: Causes & Fixes York furnace blower runs constantly? Causes include thermostat fan settings, a stuck fan relay or bad limit switch. Fixes and costs from $0 DIY to $1,800. York Furnace — Blowing cold air York Furnace Blowing Cold Air: Causes, Fixes & Costs York furnace blowing cold air? Causes from thermostat fan settings to flame-proving faults, plus fixes and repair costs from $0 DIY to $1,200. York Furnace — Ignition lockout York Furnace Ignition Lockout: Causes, Fixes & Costs York furnace ignition lockout causes include a dirty flame sensor, weak igniter and low gas pressure. See safe checks, fixes and typical repair costs.