There's no too hot water any water will do quite the same thing (e.g. 85C water will produce 85C gases), You don't have to cool the water just condense the steam and done there's a few case that you need to cool it (pool for pacu, farm, toilet, research?)
The point is liquid pipe wasn't insulated so it constantly drawing cooling potential from AETN and by routing it through metal door would make it draw faster so you're cooling a water and then send it to electrolyte Which is not a good thing.
And BTW you don't have to cool hydrogen as it will get destroyed anyway.
In short : Just slap all insulated liquid/gas pipe into your room except oxygen pipe inside AETN and isolate the room from outside by removing locked door and replace it with insulated tiles, Polluted water lock can be replaced by vacuum door.