i did zero load
no output, just a ghost reading of a few millivolts
this one is three year and 3months old, so it is not under warranty
i'm not blaming the wfco, i killed it, ventilation is of concern with the location, it had a heavy load for too long, not a short, not an overload
but just under the max, it simply got too hot
batteries alone would have tapered the power charge,
the inverter powering the heaters was a constant extended load, heat was not removed fast enough
when doing a high amp charge i will open the outside bay door
but it was raining and i plugged the electric heaters into the wrong outlets, the inverter was generating its own heat making 120v for the heaters, the wfco was making heat trying to keep the inverter happy