Appliance Error Codes Database
Found 168 verified diagnostic error codes
Gree F1: the indoor ambient sensing bulb is open or shorted
Gree assigns F1 to the indoor ambient temperature sensing bulb being open or short circuited. That bulb reads the air entering the indoor unit, which the system treats as the room temperature, so once the reading leaves its acceptable range the control has no reference against which to compare the set point. Applies to: Gree residential mini-split indoor units using the F-series sensing bulb codes described in Gree North America support Gree publishes the F-series sensing entries for its residential mini-split range. Gree also manufactures under other brand names, and a unit sold under a partner brand may present a different code set even where the hardware is related. Check the code against the manual supplied with your own indoor unit. Owner-safe checks: Read the two characters carefully and confirm it is F1 rather than F2 or another F-series entry, since the digit selects the sensor. | Compare the temperature the indoor unit reports with a thermometer placed near the intake, and record both. | Make sure nothing was left half-fitted after the last clean, particularly the front panel latch and the filter frames. Qualified technician: Gree places sensing bulb faults among the categories requiring a licensed technician, and the components sit inside the indoor casing. | Do not open the indoor unit to inspect or reseat a sensor connector. The same enclosure carries the supply to the board and the fan motor.
Gree E7 error code: two indoor units asking for different modes
Gree assigns E7 to a mode conflict: two or more indoor units on the same outdoor unit have been set to modes the system cannot run at once. Nothing has failed, and setting the heads to one agreed mode clears it. Applies to: Multi21+ and the residential ranges in the Gree code overview This meaning follows the Gree manufacturer code overview and the Multi21+ 30K, 36K, and 42K service manual. A single-zone Gree system has no second head to disagree with, and other manufacturers assign E7 to unrelated faults, so read the plate before applying anything here. Owner-safe checks: Read the mode symbol on every indoor unit in the property, including heads in rooms nobody is using. | Stop every head from its own handset, then start only the room you want, and note whether E7 returns. | Photograph both rating plates and the E7 display before contacting service, in case the code survives the checks above. Qualified technician: A conflict code that remains after every head has been set to one mode needs a technician with the wiring diagram for your capacity. | Do not remove indoor or outdoor electrical covers to look for a stuck mode signal; that work belongs behind an isolated supply.
Gree E6 error code: indoor-outdoor communication fault
On the documented Gree systems, E6 means the indoor and outdoor equipment are not communicating normally; it identifies a communication path fault, not a single failed part. Applies to: Multi21+ and documented residential mini-splits This meaning follows Gree literature for the Multi21+ capacities and the residential systems named in the manufacturer support article. Other Gree ranges, and the same characters on another brand, can be assigned to a different fault, so match the model plate before you use this page. Owner-safe checks: Record the complete indoor and outdoor model numbers and photograph the E6 display. | With the system off, confirm no recent breaker trip, outage, or visible cable damage occurred. Qualified technician: A technician should isolate power before inspecting terminals, wiring continuity, accessories, or control boards. | Do not perform the manual's powered voltage tests unless you are qualified for live electrical diagnostics.
Gree E5 error code: overcurrent and supply voltage protection
Gree assigns E5 to an overcurrent protection trip. The control has seen the compressor circuit draw more current than its limit, and Gree links this to a supply voltage that is too high or that sags and swings under load. It points at the electrical supply, the connections, or the compressor and its drive rather than one named part. Applies to: Gree residential mini-splits that publish E5 in the protection code family This reading follows the Gree code overview and service literature for the residential mini-split families that publish E5 as a protection code. Other Gree ranges and other brands can map these characters differently, so match the indoor and outdoor model plates first. Owner-safe checks: Note whether E5 trips coincide with other large appliances running and whether the lights dim when the outdoor unit starts. | Check that the isolator switch by the outdoor unit is fully on and shows no scorching or a burnt smell, without opening it. Qualified technician: Measuring supply voltage under load, checking the feed size, inspecting energised connections, and testing the capacitor, contactor, and compressor current require a qualified technician or electrician.
Grant Aerona alarms: a heat pump in a house built for a boiler
Grant Aerona alarms divide between the sealed refrigerant side of the heat pump and the water circuit it serves, and the second group is where most retrofit installations end up. A heat pump moves far more water than the boiler it replaced, so a circuit that was adequate before can leave the appliance short of flow. Applies to: Grant Aerona air source heat pumps documented in the Grant fault and support material The Aerona name covers several generations with different refrigerants and different controllers, and the alarm set differs between them. Take the model and serial number from the outdoor unit and read the alarm against Grant documentation for that unit rather than a general heat pump list. Owner-safe checks: Photograph the controller showing the alarm before anybody clears it, together with any text alongside the number. | Write down how cold it was outdoors and what flow temperature the controller had been calling for when the alarm arrived. | Feel every radiator and underfloor manifold during a heating period and map which heat well and which do not. Qualified technician: Where an alarm sits on the sealed side of the machine, only a certified person may open it: the F-Gas framework governs that in Britain and the European Union, and Section 608 does the equivalent job in the United States. | Adjusting pump settings, balancing a circuit, or altering emitters on a heat pump installation should be done by somebody working to heat pump flow rates rather than boiler practice.
Nest E74: no power detected on the Rh wire
Google Nest defines E74 as no power detected on the Rh wire. The thermostat is reporting the missing 24-volt heating-power input, not its cause. Furnace power, transformer and fuse, equipment safeties, condensate devices, Rh wiring and connection, and the thermostat input remain separate diagnostic points. Applies to: Google Nest thermostats covered by the E-code power guide This E74 definition applies to Nest models covered by Google's wiring-error guide. The 2020 Nest Thermostat can present different messages, and Rc, C, and other E-codes identify different inputs. Owner-safe checks: Save the E74 and wiring screen, identify whether equipment also lost power, and switch HVAC power off before any manual-approved connector inspection. Qualified technician: Transformer, fuse, equipment safety, condensate control, concealed wiring, voltage measurement, and thermostat-input diagnosis require qualified HVAC service.
Nest E73: no power to the Rc wire, and the cooling side behind it
These codes report that the thermostat is no longer receiving 24 volt power on a named wire. Google groups E3, E23, and E73 as no power to the Rc wire, E4, E24, and E74 as no power to the Rh wire, and E195 as no power to the R wire, so the letter in the message identifies which transformer feed went quiet rather than which component failed. Applies to: Google Nest Learning Thermostat and Nest Thermostat This page is written around the Rc group of Nest help codes. HVAC Bench covers the Rh group, headed by E74, on its own page, and the two should not be read across: on a two-transformer installation they point at different equipment in different parts of the building. Whether your system has separate Rc and Rh feeds at all is a property of the installed equipment. Owner-safe checks: Check the breakers for the heating and the cooling equipment and the service switch beside the furnace or air handler. | Replace the air filter if it is dirty, which Google includes in its own troubleshooting sequence. | Look for water in the drip pan or a blocked drain tube under the indoor unit. | Turn off power to both the heating and cooling equipment before touching any thermostat wire. | With power off, confirm each thermostat wire is straight, clean, and inserted until the connector button stays pressed down. | With power off, check whether Rc and Rh were crossed if the thermostat was recently installed, and correct them if so. Qualified technician: A blown or blackened system fuse, whose cause needs to be found before replacement. | A condensate blockage that needs the drain line cleared. | An absent 24 volt supply once breakers, switches, and wiring have been confirmed correct. | Any equipment panel that would need to be opened to reach a transformer or a safety device. | Repeated recurrence of the same code after the drainage or filter has been corrected.
Nest delayed messages: the thermostat is rationing its own battery
A Nest thermostat that says heating or cooling is delayed has detected that its internal battery is low and is postponing the call while it charges. Nothing needs to be wrong with the heating system at all. The thermostat is protecting its own ability to keep running, and the question worth asking is why it is not charging. Applies to: Google Nest learning and programmable thermostats that report power and delay conditions on screen This covers Google Nest thermostats that draw charge from the heating system wiring. Behaviour differs between Nest generations and between installations with and without a dedicated common conductor, so the Google support material for your specific model is the reference. Owner-safe checks: Note how often the delay message appears and whether it is worse in cold weather when the heating runs more. | Confirm that the heating itself works once the delay expires, which separates the control from the appliance. | Check whether a battery or power message has appeared alongside the delay at any point. Qualified technician: Running a new conductor to the thermostat position, or altering connections at a Heat Link or equipment terminal, is electrical work for a qualified person. | Do not add a conductor at the equipment end without knowing what it lands on. Heating control wiring carries mains voltage on many United Kingdom installations.
Goodman ComfortNet Eb0, Eb1 and Eb3 in cooling: why an airflow code appears while heating still works
Read them apart. The b3 entry is the only airflow condition of the three. Goodman describes it as the circulator blower motor operating in a power, temperature or speed limiting condition, and lists blocked filters, restrictive ductwork, undersized ductwork and high ambient temperature as the causes. The b0 entry says the motor is not running when it should be, and b1 says the control module has lost communication with the motor. Neither of those is a duct problem, and grouping all three sends the diagnosis to the wrong place. Applies to: Goodman and Amana variable-speed air handlers with an integrated control module reporting motor codes on a seven-segment display and through a ComfortNet thermostat These codes belong to the air handler integrated control module, and the seven-segment display alternates characters, which is why written transcriptions vary between readers. Furnace and outdoor unit codes on the same ComfortNet system come from separate tables. Owner-safe checks: Check the filter and replace or clean it according to the equipment instructions, because blocked filters are on the published cause list. | Confirm that supply registers and return grilles are fully open and unobstructed. | Record whether the code appears in cooling, in heating, or in both, and whether the blower ran at all. | Note how warm the space around the air handler gets, since high ambient temperature is listed as a cause of the limiting condition. Qualified technician: Any work on motor power leads, motor control leads or the integrated control module is inside an energised cabinet and is service work. | Duct static pressure measurement and duct sizing assessment need instruments and belong to a technician.
Goodman furnace 7 flashes: weak flame sense signal
Seven flashes on a Goodman furnace control means the flame sense current has fallen below the level the board needs to confirm a flame. The burner lights, but the control does not read enough microamps of rectified current, so it closes the gas valve and retries, then locks out after a set number of trials. Applies to: Goodman and Amana gas furnaces with an integrated ignition control that flashes seven for low flame signal This meaning applies to Goodman and Amana furnaces whose control legend lists seven flashes as a weak or low flame signal. Boards differ, so a furnace showing seven flashes for a different fault should be read against the label inside its blower door. Owner-safe checks: Watch a start-up cycle and note that the burner does light before it drops out, and count how many attempts happen before the lockout. | Confirm the furnace door is fully closed and the filter is clean, then leave the panel in place for a technician to open. Qualified technician: Cleaning or replacing the flame sense rod, checking the burner ground, measuring flame current, and adjusting gas pressure all require a qualified heating technician working inside the furnace.
Goodman six flashes: a rollout trip and a wiring fault on one count
Six flashes is a count that Goodman has assigned differently on different integrated controls, including a flame rollout trip on some and a line voltage polarity or grounding condition on others. Because those two readings have completely different risk levels, the diagnostic label inside your own furnace door decides which one applies, not a chart found elsewhere. Applies to: Goodman GMVC-series and related integrated furnace controls documented in the installation and operating instructions Goodman publishes the flash-count table on the wiring and diagnostic label of each furnace and in that model's installation and operating instructions. The count-to-meaning mapping is a property of the control platform, so a table from a different Goodman generation, or from Amana equipment on a related control, can be wrong for your furnace. Owner-safe checks: Read the diagnostic label inside the furnace door through the sight glass or during a permitted access, and record what six flashes is assigned to on that control. | Look and smell for soot, scorching, or combustion odours around the furnace without opening the burner compartment. | List any electrical work, supply changes, or generator use in the period before the code appeared. Qualified technician: A flame rollout trip requires combustion, heat exchanger, and venting assessment by a licensed gas engineer, and the reset button on a rollout device is not an owner control. | Correcting line voltage polarity or a grounding fault at the furnace supply is electrical work for a qualified person, not a matter of swapping conductors on a guess.
Goodman five flashes: flame sensed when no flame should exist
Five flashes on a Goodman integrated control reports flame sensed when there was no call for heat and the gas valve should have been closed. The control is describing gas burning outside the sequence it commanded, which is why the response is to shut down and involve a licensed engineer rather than to reset and observe. Applies to: Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions What follows is scoped to GMVC-series equipment and the flash table Goodman prints for it. Other Goodman control generations, and related brands built on similar boards, assign this count differently, so the diagnostic label fixed inside your own furnace door is the authority rather than any chart found elsewhere. Owner-safe checks: Check for any smell of gas indoors, and if one is present leave the property and use the emergency number your gas supplier publishes before doing anything else. | Switch the furnace off at its dedicated service switch so the control stops attempting cycles. | Note whether you actually saw or heard burner activity, or whether only the code was present, and record the time. Qualified technician: A gas valve that does not seat, a burner alight outside its commanded sequence, and flame sensing circuit faults are licensed gas engineering work without exception. | Do not operate, reset, or test the furnace to see whether the code returns. The condition being reported is combustion the control did not ask for.
Goodman furnace 4 flashes: open high-limit circuit
Four flashes on a Goodman furnace control means the primary limit circuit is open. The limit is a temperature safety that trips when the air leaving the heat exchanger is too hot, so the fault points at restricted airflow or poor heat transfer rather than at a failed switch. Applies to: Goodman and Amana single-stage and two-stage gas furnaces with an integrated ignition control This meaning applies to Goodman and Amana gas furnaces whose control legend lists four flashes as an open limit or open high-limit circuit. Flash-code meanings differ between control boards, so read the label inside the furnace blower door for the exact model. Owner-safe checks: With the furnace off, replace a loaded filter with the correct clean size, arrow pointing toward the blower, and confirm supply and return grilles are open and unblocked. | Note whether the four-flash code clears with airflow restored and whether it returns on the first or second heating stage. Qualified technician: Measuring temperature rise and static pressure, inspecting the blower motor, capacitor and wheel, and testing or replacing the limit switch are technician tasks, and the limit must not be bypassed.
Goodman GMVC80 three flashes: pressure switch open after the inducer starts
On the documented Goodman GMVC80 board, three flashes means the pressure-switch circuit is open when the control expects it closed. It does not prove the pressure switch is defective. The inducer, venting, condensate path, hose, wiring, and available draft all remain part of the diagnosis. Applies to: Goodman GMVC80 condensing gas furnaces This three-flash definition belongs to the GMVC80 instructions cited here. Newer Goodman furnaces can use alphanumeric seven-segment codes instead of this LED pattern, so match the model and the legend on its door before applying the meaning. Owner-safe checks: Listen to one complete heat-call sequence with every furnace panel installed and record whether the inducer starts before the code. | Look at accessible outdoor intake and exhaust openings for visible snow, leaves, nests, or damage without inserting anything. | Photograph the flash pattern twice and capture the model number and door-chart wording before power is changed. Qualified technician: Pressure measurement, hose and condensate inspection, switch testing, vent assessment, and live electrical diagnosis require qualified gas-furnace service. | Never bypass a pressure switch or hold a panel interlock to force an ignition attempt.
Goodman two flashes: the pressure switch is closed when it should be open
Two flashes on a Goodman integrated control reports the pressure switch circuit closed at a point in the sequence where the control expects it open. The control checks the switch before the inducer runs, and a circuit already made at that moment means the switch cannot prove anything about draft once the inducer starts. Applies to: Goodman GMVC-series two-stage variable-speed gas furnaces documented in the installation and operating instructions Take this from the diagnostic table printed in the Goodman GMVC-series installation and operating instructions. Goodman has used other flash counts on earlier and later control platforms, and Amana equipment built on related controls publishes its own table. Take the count from the label inside your own furnace door. Owner-safe checks: Read the flash count through the door sight glass rather than removing the blower door, since opening it can cut control power and clear the code. | Confirm the thermostat is set to heat, is calling, and has good batteries if it uses them. | Look for standing water or staining around the base of the furnace and note anything you find without touching tubing or switches. Qualified technician: Testing a pressure switch, clearing condensate tubing, and inspecting the inducer and vent path are licensed gas-furnace tasks. | Never bridge, jumper, or bypass a pressure switch to make a furnace run. The switch is the only thing confirming that combustion products are leaving the building.
Goodman GMVC one flash: external ignition lockout
On the documented Goodman GMVC80 control, one flash indicates external lockout after the furnace exceeds its ignition attempts. The control can automatically reset after one hour, while a thermostat or power interruption longer than five seconds can also reset it; none of those actions diagnoses why flame was not proved. Applies to: GMVC80 condensing gas furnaces This one-flash definition applies to the GMVC80 family in the cited Goodman installation instructions. Other Goodman boards use different LEDs and decimal codes, so identify the furnace and control before counting. Owner-safe checks: Keep furnace panels installed, record one full startup sequence and the repeating flash, and stop without creating additional ignition attempts. Qualified technician: Draft, vent, condensate, igniter, gas, burner, flame-current, grounding, safety, and control tests require licensed gas-furnace service.
GE Zoneline faults: a PTAC is one box with everything in it
A GE Zoneline is a packaged terminal unit, meaning the compressor, both coils, the fans, and the controls all sit in one chassis through the wall. That changes how a fault reads: there is no interconnecting cable to suspect, no separate outdoor unit to check, and every component behind a code is inside one sleeve. Applies to: GE Zoneline packaged terminal air conditioners and heat pumps documented in GE Appliances owner and support material Zoneline covers cooling-only and heat pump models across several generations, with different control boards and different indications. GE Appliances publishes owner and support material per model, and the code or indication on your unit is read against that rather than against a general PTAC chart. Owner-safe checks: Remove, clean, and refit the filter according to the owner manual, letting it dry fully before it goes back. | Look at the exterior grille and clear obstructions that can be reached without removing it. | Note whether other units in the same building are behaving the same way, and how many. Qualified technician: Withdrawing a chassis from its wall sleeve, testing the control board, and any refrigerant work are service tasks on this equipment. | A packaged unit carries mains supply and a sealed refrigerant circuit inside the same chassis as the filter access, so the boundary for owner work is the filter and the front panel.
Fujitsu blink codes: counting two lamps instead of one
Fujitsu indoor units without a character display report faults by blinking two indicator lamps in a coordinated pattern. The operation lamp and the timer lamp each carry a count, and the fault is identified by the pair rather than by either one, which is why counting only the light that first catches your eye produces the wrong code. Applies to: Fujitsu General residential indoor units that report faults through operation and timer indicator lamps This convention belongs to Fujitsu General residential indoor units that use indicator lamps rather than a numeric display. Fujitsu equipment with a wired controller shows codes directly, and the lamp tables differ between indoor generations, so the operation manual for your own model is the reference. Owner-safe checks: Film the lamp pattern on a phone through at least three full repetitions before interrupting power for any reason. | Count each lamp separately from the recording and write both numbers down with the date. | Confirm whether the unit still acknowledges commands from the remote control. Qualified technician: Interpreting the pair against the service tables, testing sensing elements, and checking the interconnecting cable require the casing to be opened by a qualified technician. | An outdoor protection reported through the indoor lamps involves the refrigerant circuit, which is certified work rather than an owner check.
Friedrich Floating Air: reading the display before reaching for a chart
A Friedrich Floating Air indoor unit uses one small display for three different jobs: reporting status, echoing a setting you have just changed, and reporting a fault. Characters that look alarming are frequently a mode indication or a confirmation, and separating the three is the first step rather than an afterthought. Applies to: Friedrich Floating Air ductless indoor units documented in the Friedrich product resource library The Floating Air range spans several generations with different displays and different capabilities, including models with and without built-in wireless control. The operation manual issued with your indoor unit is what maps a character to a meaning, and a chart written for another generation can be wrong. Owner-safe checks: Establish whether the unit still cools or heats when asked, since that alone separates most indications from genuine faults. | Press a remote button and watch whether the display changes and then reverts, which identifies a settings echo. | Photograph any persistent indication before interrupting power, and copy both model numbers from the data plates. Qualified technician: A persistent indication with operation stopped needs the indoor casing opened for testing, which is qualified work on this equipment. | Do not remove the front panel beyond the filter access the manual describes, since the same enclosure carries the supply to the board and the fan.
ecobee alerts: settings the installer chose, reported back as problems
A large share of ecobee alerts report that a configured threshold was reached, not that equipment failed. Compressor lockout temperatures, staging differentials, and reminder intervals are all settings somebody chose during installation, and a thermostat behaving strictly according to them can look like a fault to whoever lives with it. Applies to: ecobee smart thermostats with installer settings governing staging, thresholds, and equipment lockouts ecobee models differ in which settings they expose and under what names, and some are reachable only through installer settings rather than the everyday menus. The ecobee support material for your model is the reference for which threshold a given alert belongs to and where it is changed. Owner-safe checks: Read the full alert text rather than acting on its presence, since threshold and reminder alerts state what they are. | Record the outdoor temperature whenever auxiliary or emergency heat engages, so it can be compared against the configured lockout. | Note whether the alert began after a thermostat installation, an equipment change, or a service visit. Qualified technician: Installer settings govern how equipment stages and when it is locked out, and changing them without knowing the equipment can leave a heat pump running outside its intended envelope. | Alerts describing a sensor, a remote sensor link, or equipment that did not respond are measured conditions and need a technician rather than a setting change.