The circulating water amounted to 36m^3/day, which gives ~0.41l/s, that's 410g/s. 1g of water needs 4.1J/g to increase 1C, so that quantity of water absorbed ~1700W for every C. Water entered at 60C, so, we have that the liquid part absorbed ~70kW. The latetent heat of water, assuming, 1 atm, is ~2.3MJ/kg. So, 410g/s of water can absorb ~930kW by completely vaporizing.
So, we have that an amazing coincidence 1MW (~70kW + ~930) is nearly *exactly* what is needed to vaporize the flux in the circuit. Water has 18g/mol and 1 mol of steam gives 22.5l. We have 512l/s of steam out of the heater. The machine has the dimensions of 20x3x3m^3=180m^3 or 180,000l. There can be probably space for cooling. I'd use water street to cool it down (and heat the building, for example) and fans to cool the room. Otherwise, probably the water is high pressurized and bubbling.