Fault Code Reference

Enphase Fault Codes

Enphase microinverters and IQ Battery storage. Module-level power electronics with per-panel monitoring, widely used in UK residential solar installations.

49

Fault codes

Device types covered

Inverter (49)

Common fault codes

AC Voltage Out of Range

Check voltage at the consumer unit and at a socket near the inverter. Log over t…

AC Frequency Out of Range

Check frequency in Enlighten or with a power quality analyser at the consumer un…

DC Resistance Low (Ground Fault / GFDI)

Identify the specific microinverter(s) flagging this event in Enlighten. Inspect…

DC Input Voltage Too Low

Check the affected module location in Enlighten. If shading is present at the ti…

DC Input Voltage Too High

Confirm only one module is connected per microinverter. Verify module Voc at STC…

Critical Temperature

Check air gap behind modules meets Enphase minimum (typically 1 inch / 25 mm). C…

All Enphase fault codes

AC Voltage Out of Range

Check voltage at the consumer unit and at a socket near the inverter. Log over t…

AC Frequency Out of Range

Check frequency in Enlighten or with a power quality analyser at the consumer un…

DC Resistance Low (Ground Fault / GFDI)

Identify the specific microinverter(s) flagging this event in Enlighten. Inspect…

DC Input Voltage Too Low

Check the affected module location in Enlighten. If shading is present at the ti…

DC Input Voltage Too High

Confirm only one module is connected per microinverter. Verify module Voc at STC…

Critical Temperature

Check air gap behind modules meets Enphase minimum (typically 1 inch / 25 mm). C…

Grid Gone / No Grid

Check consumer unit — confirm grid is present and all MCBs/RCDs are reset

MI Not Reporting

Microinverter Failed to Report

Check Enlighten — note which MIs are not reporting and their positions on the ar…

AC Voltage High on Branch (Voltage Rise)

Measure voltage at the consumer unit and at the far end of the AC branch. A diff…

Pairing / Discovery Failure

Confirm the MI is producing DC (check at module terminals) and AC is present. Op…

Production Issue / Below Expected

Open Enlighten and check individual MI performance — identify which MIs are unde…

IQ Gateway Offline

Check broadband connection at the property. Confirm WiFi SSID and password have …

Gateway Amber Device LED

Open Installer Toolkit and check which MIs are not communicating. Note their pos…

Enlighten Stale

Enlighten Data Staleness

Check Gateway LEDs. Green network LED = online. Amber = connecting. Off = no net…

IQ Battery Not Reporting

Check IQ Combiner and IQ System Controller LEDs — should be solid green. Check b…

IQ Battery Not Charging

Check Enlighten for battery SoC. If at 100%, charging correctly stopped. Check b…

IQ Battery Not Discharging

Check SoC in Enlighten. If at minimum reserve (default 20%), battery is protecti…

IQ Battery PCU (Power Conversion Unit) Fault

Check battery temperature and ventilation. Power cycle the battery (follow Enpha…

G98/G99 Grid Disconnect Event

Check Enlighten for the time of the disconnect event. Cross-reference with grid …

Profile Not Set

Grid Profile Not Set

Open Installer Toolkit. Select the system and go to Grid Profile. Apply the corr…

Firmware Update Failure

Check Enlighten for update status. Confirm internet connection is stable. For MI…

Very Low SoC — Recovery Mode

Allow grid to recharge battery. This is a protection state — do not attempt to f…

Ground Fault Disconnect Interrupt

Identify the affected MI in Enlighten. Inspect DC Q-connectors and cables at tha…

Battery High Temperature Shutdown

Check the battery installation environment. IQ Battery 5P requires ambient below…

Battery Low Temperature -- Charge Restricted

Check battery ambient temperature. IQ Battery 5P requires minimum 0C for chargin…

Battery Cell Fault / Voltage Imbalance

Check Enlighten for battery State of Health and cycle count. A cell fault on a b…

Storm Guard -- Battery Reserve Mode Active

This is not a fault. Storm Guard holds the configured reserve and limits normal …

Production Schedule Failure

Check Gateway internet connectivity (ethernet or WiFi LED). Confirm broadband is…

Gateway Cloud Communication Timeout

Check Gateway network LED. Confirm broadband is working. If WiFi: confirm router…

Profile Mismatch

Grid Profile Does Not Match Detected Grid

Open Installer Toolkit, go to Grid Profile. Verify UK G98 (below 3.68kW export) …

5P: Solid Yellow

Battery Overtemperature Shutdown

Check ambient temperature at battery location (operating range: -20°C to 50°C). …

5P: Yellow 1 Flash

No Communication with IQ Gateway

Check IQ Gateway is powered and shows solid green Network LED. Check Comms Kit 2…

5P: Red 2 Flash

IQ Battery 5P Error State

Check Enlighten/Enphase app for 'PCU Fault' or specific event. Perform DC switch…

5P: Soft Pulse Red

DC Switch ON But No AC Supply

Check the battery's dedicated MCB in the IQ System Controller or electrical pane…

5P: Red 3 Flash

DC Switch is OFF — Normal State

Press the DC switch button on the front of the battery. LED should change to gre…

5P: G100 Lockout

G100 Export/Import Violation Lockout

This lockout can only be cleared by Enphase Support — call +44 1908 828 928. Do …

3T: Red 2 Flash

IQ Battery 3T Error State

FIRST CHECK: physically confirm the COMMS-KIT-01 Zigbee USB dongle is plugged in…

3T: No Discharge

IQ Battery 3T Not Discharging — Zigbee Comms Lost

Confirm COMMS-KIT-01 dongle is in IQ Gateway USB port. Without this dongle, IQ B…

GW: Net LED Red

IQ Gateway Connected to LAN But No Internet

Check broadband on another device. If no internet elsewhere — ISP or broadband o…

GW: Prod LED Red

IQ Gateway: One or More Microinverters Not Producing

Check time of day — solid red Production LED is normal at night and low-irradian…

GW: Dev Comm Red

IQ Gateway: One or More Devices Not Communicating

Open Installer App and identify which devices are not communicating. Note their …

Comb: All 4 Flash Red

IQ Gateway Rebooting

Wait 3 minutes. LEDs should return to normal operating state after boot. If a fi…

Comb: All 4 Flash Green

IQ Gateway Firmware Update In Progress

Do not power off, switch off MCBs, or disconnect internet during this sequence. …

IQ EV Charger 2 — Fault State

Check the upstream MCB/RCBO feeding the charger has not tripped. Check earth con…

EV: Alternate Blink Red

PEN Fault — Do Not Use Charger

Do not attempt to reset or use the charger. A PEN fault is a serious supply safe…

Charge Scheduled / Delayed (HEMS)

Check Enphase app schedule. If charging is needed now, override the schedule man…

IQ Relay — No Grid Profile Set

Open Enphase Installer Toolkit. Connect to this system. Navigate to Grid Profile…

Relay: Green Red

IQ Relay — Frequency Protection Trip

Check grid frequency with a power quality meter. If frequency has normalised, re…

Relay: Stuck Open

IQ Relay Contactor Mechanically Failed Open

Confirm both LEDs are solid green and grid profile is set. Check with a voltage …

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