IQ Gateway Device Communications LED is solid red — Gateway cannot communicate with one or more devices (MIs, batteries, IQ SC).
Common causes
PLC (Power Line Communication) interference from EV charger, LED dimmer, or UPSMI powered offRF interference on AC branch (IQ Battery 3T wireless systems)AC branch fault isolating devices
What to check
STEP 1
Open Installer App and identify which devices are not communicating. Note their location — if clustered on one branch, check that branch's MCB and wiring
STEP 2
Check for PLC interference sources on the same electrical phase (EV chargers, LED dimmers, UPS, variable speed drives). Temporarily disconnect suspect devices and retry
Escalate if
All MIs powered, no obvious PLC interference, but comms still lost — run device scan in Installer App. Single device not communicating after scan = hardware fault on that device
Need full interactive diagnosis?
Faultpath walks you through decision trees, fault codes, and commissioning — built for solar & battery engineers.