Victron inverters report faults two ways. The LEDs on the front panel blink in patterns that tell you the category of the problem, and units on a VE.Bus network (MultiPlus, Quattro) log numbered errors that show up in VictronConnect, on a GX display, or on VRM. This guide decodes both and tells you what to check. It is written for the common RV units: MultiPlus, MultiPlus-II, Quattro, and the Phoenix VE.Direct inverters.
The general rule for every Victron LED: blinking is a warning, solid is a shutdown. A blinking "low battery" LED means the inverter is still running but the battery is close to the cut-off. A solid one means it has already switched off.
The patterns below are from the MultiPlus and Quattro manuals. Firmware and model variations exist, so treat this as a starting point and confirm against the manual for your unit.
MultiPlus and Quattro front-panel LEDs
The panel has three groups: charger LEDs (mains on, bulk, absorption, float), inverter LEDs (inverter on, overload, low battery, temperature), and on some models an "alarm" LED.
| LEDs | Meaning | What to check |
|---|---|---|
| Inverter on, solid; nothing else | Inverting normally | Nothing |
| Low battery, blinking | Battery voltage near the low cut-off; inverter still running | State of charge on the SmartShunt; loose or undersized battery cables causing voltage sag |
| Low battery, solid | Shut down on low battery | Charge the battery; check that the DC cable and fuse are not causing a drop at the inverter terminals |
| Overload, blinking | Load near the inverter's limit; pre-alarm | Reduce load; check for a motor start (A/C, compressor) that briefly exceeds the rating |
| Overload, solid | Shut down on overload | Remove the load, restart; if it trips with no load, check for a short on the AC output |
| Temperature, blinking | Running hot; pre-alarm | Ventilation around the unit, ambient temperature, dust on the fan |
| Temperature, solid | Shut down on high temperature | Let it cool; fix airflow; the unit derates above roughly 104°F (40°C) ambient |
| Low battery and overload blinking together | DC ripple voltage too high (pre-alarm) | Battery cables too long or too thin, loose lugs, a battery that cannot supply the current |
| Low battery and overload solid together | Shut down on DC ripple | Same as above; this is almost always cabling |
| Overload and temperature together | Overload plus high temperature | Reduce load and fix ventilation |
| Bulk / absorption / float blinking with mains on | Charger active, but limited or a transfer issue | If mains LED blinks, input voltage or frequency is out of range; see below |
Mains on, blinking: the AC input is present but the unit will not accept it. On a generator this is usually frequency or voltage outside the accepted window, or a ground/neutral bonding issue. On shore power, a bad pedestal. The MultiPlus has a "UPS mode" and "weak AC" setting that widens tolerance for generators; a VE.Bus Smart Dongle or MK3 interface lets you change it.
Phoenix VE.Direct inverter LEDs
The smaller Phoenix inverters use a single or dual LED with blink codes rather than a panel. Green blinking is normal operation, a red or alarm LED blinking means pre-alarm, solid means shutdown, and the number of blinks indicates low battery, overload, high temperature, or ripple. The Phoenix Inverter Control panel ($103.00) and VictronConnect over Bluetooth give the fault by name, which is easier than counting.
VE.Bus error codes
These appear as "VE.Bus Error N" in VictronConnect, on a Cerbo GX display, or in VRM. Most only occur in multi-unit (parallel or three-phase) systems, but a few show up on single RV units.
| Error | Meaning | Typical cause in an RV |
|---|---|---|
| 1 | Device is switched off because one of the other phases switched off | Parallel/three-phase systems only |
| 3 | Not all, or more than expected, devices found | A unit in a parallel set is off, or a VE.Bus cable is unplugged |
| 4 | No other device detected | Cable fault between units |
| 5 | Overvoltage on AC-out | A generator or second inverter feeding the output; wrong wiring |
| 8 | Ground relay test failed | Neutral-ground bonding problem; often a shore cord with reversed polarity or a mis-wired transfer switch |
| 10 | System time synchronization problem | VE.Bus cable or firmware mismatch |
| 11 | Relay test fault | Internal relay or back-feed; usually needs service |
| 14 | Device cannot transmit data | VE.Bus cable, or a non-Victron device on the RJ45 bus |
| 15 | VE.Bus combination error | Mixed models or firmware in one system |
| 16 | Dongle missing | Multi-unit configuration expected a dongle |
| 17 | Phase master missing | Parallel/three-phase |
| 18 | AC overvoltage on the output of a slave | Parallel systems |
| 22 | Device cannot function as slave | Model not suitable for parallel |
| 24 | Switch-over system protection initiated | Back-feed relay detected AC on the output while inverting; a wiring fault or a generator connected to the wrong terminals |
| 25 | Firmware incompatibility | Update firmware on all units to the same version |
| 26 | Internal error | Contact your dealer |
For a single MultiPlus in a trailer, errors 8, 14, and 24 are the ones that actually turn up. Error 8 almost always traces to the shore cord, pedestal, or an added transfer switch. Error 24 means something is putting AC onto the inverter's output while it is inverting, which is dangerous; do not reset and ignore it.
The five faults that cause most RV calls
- Low battery shutdown with a "full" battery. Voltage at the inverter's terminals is lower than at the battery because of cable size, length, or a loose lug. Measure at both ends under load. The cable and fuse sizing chart gives the correct gauge.
- Overload on A/C start. A rooftop air conditioner's start surge can exceed a 2,000 VA unit's peak. A soft-start on the A/C or a larger inverter is the fix; see the soft-start guide.
- Temperature shutdown in a closed locker. The MultiPlus needs clearance and airflow; mount it vertically with the manual's clearance and add a 12 V cooling fan to the compartment if needed.
- Ripple. Lithium batteries with a BMS that has gone into a limited state, or an undersized bank, cannot supply the pulses the inverter draws. The fix is a bigger bank, shorter cables, or a BMS that is not limiting, such as the Smart BMS 12-200 configured correctly.
- Mains rejected from a generator. Enable the weak-AC/generator setting, and confirm the generator's neutral is bonded as the MultiPlus expects.
Before you call for warranty
Victron products carry a manufacturer warranty, but most "faulty inverter" returns are installation issues. Have these ready: a photo of the DC cabling and fuse, the cable gauge and length, the battery type and capacity, the VictronConnect fault log, and the firmware version. The VRM portal keeps a history that makes diagnosis far faster.
Shop this
- Victron VE.Bus Smart Dongle — $100.00
- Victron Cerbo GX MK2 — $264.00
- Victron SmartShunt — from $99.99
- Victron MEGA-fuse 400A & 500A, 5-pack — $18.00
- Victron Phoenix Inverter Control Panel — $103.00
- Inverter/Chargers (120V) (collection)