Ways to Field Test or Repair my Multiplus 3000?

So this one's close to home for me — literally happened in my van last winter parked up on the South Downs during a proper storm. Lightning struck somewhere nearby and my Victron Multiplus-II 12/3000 started behaving erratically afterwards. Charging worked fine but the inverter side kept dropping out under any meaningful load.

Here's what I did to narrow it down before assuming the worst:

Basic field checks first:

• Pulled the unit completely, checked all DC connections and the AC wiring for any signs of scorching or arcing
• Used VE.Configure to read the unit's internal fault history via a laptop — invaluable, this
• Checked the transfer switch relay by listening carefully during AC passthrough (a clicking or stuttering relay is often the culprit after a voltage spike)

The bit most people miss — check your RCD and any surge protection devices upstream of the Multiplus. Mine had a Victron Energy Protection device that had quietly sacrificed itself doing its job. Replaced that and suddenly everything cleared up.

If you're getting comms faults on the Cerbo GX side too, don't assume it's the Multiplus — the VE.Bus interface chip can be knocked by transient spikes independently of the inverter hardware.

Worth contacting Bimble Solar or Victron's UK support via ADVERC if you're stuck — they've both been genuinely helpful when I've rung with daft questions.

Has anyone else here had storm-related damage to their Victron kit? Curious whether anyone's successfully done a DIY board-level repair or whether it always ends up being a warranty/depot job.

@SussexVanLifer that sounds genuinely awful — storm + dead inverter in a van is a nightmare scenario.

Quick question before you start poking around inside it: have you checked whether Victron's warranty covers surge/lightning damage? I know it's a grey area but worth a call to your UK distributor first (Bimble or Eco Experts are often helpful on this).

Also — did you check the VE.Bus fuse on the unit itself? My Multiplus-II threw a similar wobble after a power event and it turned out to be the internal protection rather than actual board damage.

If it is toast, have you looked at getting it bench-tested by a Victron-approved service centre? I think there are a few dotted around the South East. Might be cheaper than a straight replacement depending on the damage.

What does VictronConnect actually show when you connect to it?

@SussexVanLifer before anything else, connect it to VictronConnect via the VE.Direct port and check what fault codes are showing — that'll tell you whether you're dealing with a fried input protection stage or something deeper on the transformer side.

If you can't get comms at all, that's usually a bad sign (blown processor or power supply rail).

Practically speaking:

• Don't attempt internal repairs unless you're a qualified electrician — Victron UK's warranty repair network includes places like Bimble Solar and Merlin Equipment who do proper bench diagnostics
• Victron's own fault-finding flowcharts are in the Multiplus-II manual (section 7 ish)
• If it was a nearby strike, check your fusing and any surge protection devices in the system too — secondary damage is common

Worth raising a ticket with your dealer before cracking it open yourself.

@BlownFuse already nabbed the VictronConnect tip but if that's a dead end, my cabin Multiplus threw a wobbly last spring and Victron's warranty team were surprisingly decent — log a ticket before you crack it open or you'll void any chance of a claim faster than I void my DIY electrical warranties 😬

@SussexVanLifer been there mate — my motorhome's Multiplus took a wobble after a dodgy shore power incident and the first thing beyond VictronConnect (already covered, cheers @BlownFuse) is to physically inspect the internal MOSFETs for visible burn marks — pull the cover and look for scorched components near the DC input stage.

If the unit powers on but behaves erratically, try a full settings reset via VEConfigure before assuming it's hardware — sometimes the firmware just throws a tantrum after a surge.

Worth checking:

• DC fuse on the unit itself (obvious but people miss it)
• The transfer switch relay — lightning can weld those contacts shut
• AC output terminal block for carbon tracking

Victron's repair network is patchy outside major cities so honestly, Victron's official service partners list is your best shout before you crack it open yourself.