Furnace, washer, dishwasher, AC and water heater error codes
Type the code from the status light or display. Each page gives the manufacturer's meaning, the likely causes, the checks a homeowner can do, and the point where the manual hands the job to a licensed technician.
Browse by equipment and brand
Each code comes from a named manufacturer document, linked on every page.
Furnaces151 codes
Washing machines35 codes
Dishwashers48 codes
AC and heat pumps67 codes
Tankless water heaters11 codes
Codes on file
A sample from each equipment type and brand. Search above, or browse the full list.
Furnace lockout after an excessive number of ignition retries (3 total): flame was not established, or flame was lost after it was established.
E04American Standard · furnaceOpen limit: the main thermal limit, a rollout switch, or the reverse airflow switch.
12Bryant · furnaceBlower on after power-up. The blower runs for 90 seconds if the furnace is powered up during a call for heat, or if that call opens during the blower on-delay. The same guide's sequence says the amber LED flashes 12 during those 90 seconds, then stays on continuously if no fault is found.
11Carrier · furnaceNo previous code. The service label says stored status codes are erased automatically after 72 hours.
E10Goodman · furnaceGrounding fault / poor neutral connection.
Alternating fast flashLennox · furnaceImproper main ground, OR line voltage below 90 volts. Control will not respond to a heat call until voltage rises above 95 volts.
10Rheem · furnaceOne-hour lockout, caused by repeated failed ignition (11), water sensed (59), dead blower (61), internal fault (93), flame lost 5 times (13) or unexpected flame (14).
E01Trane · furnaceLoss of the IRQ or other internal failures (internal furnace control error).
1 red flashYork · furnaceFlame was sensed when there was not a call for heat. The control turns on both the inducer motor and the supply air blower.
AELG · washing machineLeakage error: the washer has detected a water leak inside the appliance and its anti-flood safety switch has been activated.
3CSamsung · washing machineMotor error: Samsung lists 3C, 3E, E3 and 1 3C as a motor error. On some models 3E is a voltage error instead, so check your user manual.
F0 E5Whirlpool · washing machineOff balance: an unbalanced load can lengthen the cycle and leave clothes dripping.
Field guides
The questions homeowners ask most, answered from manuals and DOE, ENERGY STAR and NFPA guidance.
Furnace No Heat: Winter 2026 Checklist
Winter 2026 checklist for a gas furnace with no heat. Each step cites the manufacturer manual and links the matching fault-code page.
Furnace Ignition Lockout: It Tried to Light and Stopped
What an ignition lockout means on York, Amana, American Standard, Bryant, Carrier, Goodman and Trane, and which checks the manuals leave with a homeowner.
Heat Pump Not Heating in the Cold
Why a heat pump can blow cool air or stop heating in cold weather, from Carrier's defrost rules and the outdoor-sensor codes, plus the American Standard balance-point setting.
How to Read a Furnace LED Flash Code
How to find and read the blinking LED or display code on a gas furnace control board, with brand-by-brand examples from the manuals.
Washer Will Not Drain: OE, 5C and F9 E1
What LG OE, Samsung 5C and Whirlpool F9 E1 mean when a washer will not drain, and the hose, filter and suds checks each brand publishes.
Dishwasher Will Not Drain: E24, C1, OE and 5C
What Bosch E24 and E25, GE C1 and C3, LG dishwasher OE and Samsung 5C mean when a dishwasher will not drain, including filters, air gaps and the disposal knockout.
AC High and Low Pressure Codes
What Carrier 31, 32, 83 and 84 and Goodman 01, L1, 02 and L2 mean on an AC or heat pump, and which airflow checks the service manuals leave with the homeowner.
Furnace Rollout Codes and Carbon Monoxide Safety
What a furnace rollout or open-limit code means, which of those codes are technician-only, and what CPSC says about carbon monoxide alarms and symptoms.
Washer Suds Codes: HE Detergent and Too Many Suds
What LG Sud, Samsung SUd and Whirlpool Sud mean, how much detergent those pages allow, and how suds also cause drain and leak codes.
How these pages are built
The same rules on every code.
Meanings and causes come from the manufacturer's manual or official support page, and each page links to that document. If a code could not be confirmed in a manual, it is not on the site. Steps are split into what a homeowner can safely check and work that needs a licensed technician. More on sourcing.