Victron Multiplus 12 / 500 / 20 gives 5V and 12V but no 220V

Had something weirdly similar happen with my Multiplus last summer — proper head-scratcher moment.

Mine was showing healthy battery voltage on the Victron Connect app, the charging side was working fine pulling from the hook-up, but absolutely nothing coming out on the AC side. Just... silence from the inverter.

Turned out the AC output relay had gone a bit temperamental. A firmware update via VE.Direct sorted it in my case, which felt like cheating if I'm honest 😄

A few things worth checking if you're in the same boat:

• Assistants / ESS settings — sometimes the passthrough gets disabled if the input current limit is set too low
• VE.Configure — worth pulling the full settings dump and checking the AC input/output configuration hasn't gone wonky
• Check for any active alarms in Victron Connect, even minor ones can cause the relay to stay open
• Is your shore power input within spec? If the Multiplus sniffs anything dodgy (frequency, voltage spike) it'll refuse to pass through as a protective measure

The 5V/12V outputs working fine does suggest the unit itself isn't completely cooked, which is promising. More likely a relay or software config issue than a full hardware failure.

Anyone else on here had relay issues with the 500VA model specifically? Feels like the smaller units are a bit more precious about input quality than the bigger 2000/3000 units. Curious whether this is a known thing or just my terrible luck with campervan electrics in general 🤣

MeadowHermit | 847 posts | ⚡ Off-grid since 2019

@LK_Solar curious timing on this thread — the 12V and 5V outputs working whilst the 230V inverter side is dead usually points to a few specific culprits.

First thing I'd check is whether the unit has thrown a protection fault — sometimes the inverter section shuts down independently without it being obvious in VictronConnect. Connect via Bluetooth and look specifically at the alarm log rather than just the live readings.

Also worth checking your input voltage is genuinely above the low-voltage disconnect threshold. Even if it looks fine, a weak cell under load can trick you.

Have you got a MultiPlus or MultiPlus-II? The older units can have relay issues that present exactly like this. What does the LED sequence show on the front panel when you attempt to get 230V output?

MuddyTrekker | 312 posts | 🔌 Static caravan + EV nerd

Worth checking the AC output relay — on my old 500VA unit the relay contacts corroded after a damp winter and it threw exactly this symptom. Victron Connect showed everything healthy but no 230V out.

Quick test: if you've got a multimeter, probe the AC output terminals directly rather than trusting the app readout. The inverter logic can report "inverting" without the relay actually closing properly.

Also — is this unit mounted somewhere with poor ventilation? Mine was tucked in a tight locker and thermal cycling over winter didn't help the relay longevity one bit.

If the relay is the culprit, Victron UK support are decent and depending on age it might still be within warranty. Otherwise a competent auto electrician can swap the relay for under £50 parts cost.

JA_Solar | 203 posts | ☀️ Shepherd's hut + emergency backup

One thing nobody's mentioned yet — have you checked the transfer switch settings in VE.Configure? I had a 500VA unit on my shepherd's hut backup setup that would refuse to output AC if the "AC input current limit" was set too low and it was getting confused about whether shore power was present.

Also worth a look: the overtemperature protection can silently kill AC output while leaving 12V charging totally fine. Mine did exactly this during a hot spell last July — everything looked healthy in VictronConnect but the inverter side had quietly shut itself off.

Try running VE.Configure via a USB-MK3 interface if you haven't already — the live data view shows relay states properly, which the app sometimes doesn't surface clearly.

EcoFlow_Master | 1,204 posts | 🏕️ Static caravan off-grid

Had almost this exact situation on my static last winter. The Multiplus sat there looking perfectly healthy — Victron Connect showing everything green — but the AC output was simply dead.

Turned out to be the transfer switch internally. The unit had gone into a protection state I'd never seen before, no alarm, no obvious flag. A full power cycle sorted it temporarily, but the real fix was a firmware update via VictronConnect that addressed a known bug in that firmware revision.

Worth noting — if you're on anything older than v430, it's genuinely worth updating before pulling the unit apart. Saved me a lot of unnecessary grief.

@MuddyTrekker makes a fair point about the relay, though on the 500VA the firmware issue tends to mimic relay failure convincingly.

ZoeGrant | 847 posts | 🔧 Full-time off-grid narrowboat + solar array

Worth narrowing this down systematically before swapping hardware. On my Multiplus 24/3000 I had a similar AC output failure whilst charge/DC functions remained healthy — turned out to be the internal transfer switch had partially failed.

Specifically on the 12/500 variant: check your VE.Configure settings via VEConfig or VictronConnect — particularly the AC output enable flag. Sounds daft, but firmware updates occasionally reset that parameter.

Also confirm your grid code settings aren't mismatched for the UK 230V/50Hz spec. Some units imported via grey-market channels arrive configured for other regions.

@JA_Solar is probably heading toward the temperature cutout — these compact 500VA units throttle hard in warm enclosed spaces, but they'd typically throw a fault LED rather than silently drop AC.

What does VRM or VictronConnect show under the 'inverter' status tab specifically?