Impossible to find anywhere to post a bug report so I’m doing it here. I have an MP II GX/Pylontech ESS setup with solar, the grid and all loads connected to AC input in. I have set the grid max input to 50A (we have a 12kVA/230V) supply. I have set a schedule to charge the batteries to 90% from 1…

Taking the car charging current down from 32A (7700W) to 20A (4800W) has stopped the fan running. But why is the fan running anyway when the MP2GX is totally cold? Shouldn’t it be temperature driven? [Screenshot_20250917-231642]

I’ve done a workaround which is to move the EV charger to the grid side of the MP2’s CT clamp. So now the MP2 can’t see it. I’ve done that using the subtraction method: running the EV charger feed in the consumer unit through the CT clamp in the reverse direction to the grid feed. So feed → load for…

In my experience the fan runs (on all victron inverters) when there is a larger load being processed as well. As a person who has used other inverter brands would honestly say it is a better method rather than waiting for components to get got then trying to cool them afterward. From an electrical…

Hi and thx for your reply. The thing is that the inverter is not processing any load when the fan is running at maximum sounding like a jet engine! It is observing an 8kW load via a CT clamp but nothing is passing through the inverter. Negligible input via AC IN and nothing is connected to AC OUT 1 …

[image] Reeshar: nothing is connected to AC OUT 1 or 2 In the gx, is it set up that way ?

Same issue here with Multiplus-II GX 48/3000. Fan turns on when the current sensor sees more than 7500Watts power flow to grid.. Either a bug, or possibly a current sensor burden that might heat the inverter pcb near temperature sensor ? Painfull for me, as it does occur >1000hours/yr..

Fans aren’t purely driven by heat they are also driven by load, so it is more likely that the system does not distinguish between pass-through and inverted loads.

…which sounds a bit crazy to me. Surely the fan is intended to cool the MP2, so why hasn’t it been programmed to only run when it is processing a heavy load? TBH, judging from comments on a larger MP2 running hot and the fan not running, it seems to me that Victron should splash out on a temperature…

It works on both temp and load.

Bug report: fan runs at max speed on MP2GX even though not charging

DIY

Reeshar 20 September 2025 13:41 7

So yes, AC Out is disabled. Essential vs critical is not presented as an option since it is irrelevant: there’s no way of distinguishing what loads are present on AC In.

I’m not sure whether there were other settings you were referring to…

Multiplus 2 gx fan turns on at high grid measured injected power (but no MPII activity)

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Bug report: fan runs at max speed on MP2GX even though not charging

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