Enabling ESS on a houseboat with Color Control GX and Pylontech

Got a mate with a narrowboat who's hit exactly this wall — Victron Color Control GX happily chatting to his Pylontech stack via CAN-bus, system ticking along beautifully for three years, then he tries to enable ESS and gets the classic "ESS assistant not found" slap in the face.

Turns out the ESS assistant has to be flashed directly onto the Multiplus via VE.Configure — the Color Control can't do it remotely, which catches everyone out the first time.

Steps that sorted it for him:

1. Grab VE.Configure on a Windows laptop (yes, it has to be Windows, welcome to 2003)
2. Connect directly to the Multi via MK3-USB interface
3. Download the assistant from within VE.Configure and flash it to the unit
4. Re-run your settings — ESS will wipe your existing assistant config

Worth noting: houseboats and narrowboats can be fiddly with ESS because of shore power connections at marinas — some UK marinas have absolutely grim earthing arrangements that'll make your Multi throw a fit once ESS starts managing the grid input. Might be worth checking your "AC input current limit" settings while you're in there.

Anyone else running ESS on a floating setup in the UK? Curious whether the marina shore power headaches are universal or just his particularly dodgy mooring in the Broads.

Interesting one this — the CAN-bus comms working fine doesn't necessarily mean ESS assistant is properly configured underneath. Worth checking whether the ESS assistant is actually installed in the inverter/charger via VEConfigure, not just the CCGX settings. Easy to assume it's there when it isn't.

Also with Pylontech and ESS, the DVCC settings are critical — specifically SVS and SCS need enabling so the battery's own voltage/current sense takes priority. After three years something may have reset following a firmware update; Victron pushed some significant CCGX firmware changes around v2.8x that caught a few people out.

What inverter/charger is paired with the CCGX? MultiPlus or Quattro? That matters for which ESS configuration options are actually available.

Ooh this rings a bell — is the ESS assistant actually installed on the Multis/Quattros themselves, or just assumed to be because the CCGX is showing battery data fine? Those are two completely separate things and I made exactly that mistake on my narrowboat setup.

Worth your mate checking in VEConfig (needs a laptop and MK3-USB cable) rather than just the CCGX interface. The assistant has to be loaded onto the inverter firmware directly.

Also — did anything update recently? Victron pushed some firmware that shifted ESS requirements around that time on a few devices. @Squib82 probably knows more about the CAN-bus side than me but I'd start with confirming the assistant is actually there before digging deeper. What firmware version is the Multi on currently?

@NorfolkVanLifer the classic "it worked fine until it didn't" — narrowboats are basically floating motorhomes with better curtains.

Worth checking whether the DVCC (Distributed Voltage and Current Control) settings in the CCGX are actually enabled — Pylontech stacks need DVCC on to hand BMS control properly to the Color Control, otherwise ESS gets confused about who's actually in charge of charge limits.

Also, three years is about when firmware drift becomes a real issue — the CCGX, Pylontechs, and any Multis all need to be on mutually compatible firmware versions or the CAN-bus handshake quietly starts lying to you.

Check Venus OS version on the CCGX; anything below v2.80 has known ESS quirks with Pylontech. VictronConnect will show you if the BMS is actually broadcasting correctly or just pretending to behave.

@ThingamyBob raises the key point — the ESS assistant lives on the inverter/charger firmware, not the CCGX itself. Had a similar head-scratcher on my own boat last year.

Worth checking:

• What firmware version is running on the Multi/Quattro? ESS can get temperamental after certain VE.Bus updates
• Has the VEConfigure assistant list actually been checked, not just assumed to be there?
• Pylontech comms working fine via CAN doesn't automatically mean the battery parameters ESS needs (min SOC, discharge floor etc.) are being passed through correctly

On a narrowboat specifically, is he running a Cerbo GX or genuinely the older Color Control? The CCGX has some ESS limitations the Cerbo doesn't. Might be worth the upgrade if he's already three years in — they're not that dear now.

What error or behaviour is he actually seeing when it fails?

@KellyRobinson @ThingamyBob — yes exactly, and worth checking which VE.Configure version was used to push the assistant originally. Had a similar scramble with my shepherd's hut setup — CCGX showed everything healthy but the Multi had silently reverted after a firmware update and ESS just... stopped arbitrating properly.

Quick checklist for your mate:

• Connect laptop directly to the Multi via VE.Bus (not through CCGX)
• Open VE.Configure and check the assistant list — should explicitly show ESS assistant installed
• Cross-reference the ESS firmware minimum requirements — Pylontech integration tightened up around CCGX v2.80 ish

Also worth pulling the Venus OS logs rather than just eyeballing the CCGX dashboard — the dashboard can look deceptively calm while things are quietly misbehaving underneath. Narrowboat environments are brutal on connectors too, so check the CAN-bus termination resistor while he's at it.