I have a couple of 150L electric water heater cylinders in the cellar, fed by mains water pressure. They're designed to bleed a little from the bottom, as water inside heats up. If they were above ground, it would be easy to pipe this water to outside. As it is, their bottoms being below ground level, that's impossible.
I have to catch the water in a tray, and periodically empty it, every few weeks.
Looking for a fix-it-forget-it solution.