So for the last few months I've had an unexplained (tidal?) pool in the mechanical room of our house. It's not sunny or deep enough so my wife could use it as a therapy pool for her Watsu work, and I can't stock it with fish either. Ideally, I would prefer if it just went away and never came back, rather than having to regularly mop the floor.
The problem is that is seems to be close to impossible to find the source of the leak. Both the plumbers who have done other good work on the house before and myself suspect that it's somehow an issue with the water filtration system, but it seems to be a Heisenbug in the sense that it doesn't seem to occur when someone is watching. I have cups under all the drains/overflows that I would normally expect to leak like the hot water emergency overflow/pressure relief and the overflow for the water softener's brine tank. They're all bone dry, of course, no matter how much water ended up on the floor.
The plumber suspects that it might be a defect in one of the cylinders that are part of the water filtration system - one air separator for the air injection system that looks a bit like a welding gas cylinder and is metal, and two fibreglass ones that are for the softener and PH neutralizers. Neither of the three leaks in normal operation or when I run the backwash cycles and observe it. The problem does seem to happen overnight as I usually check the mechanical room in the morning and evening at the moment and it's normally dry. I've been trying to figure out the pattern of the problem appearing, but so far I'm drawing a blank.
Right now the main problem I have is that it seems impossible to figure out exactly which part is leaking. Firing the part cannon at the mechanical room - as much as I would like to do that, because I don't agree with some of the decisions they made when configuring the house - is a very expensive prospect with uncertain outcome, so better to be avoided for now.
Which leaves me with the question - how on earth do I figure out where the leak is coming from before everything in the mechanical room gets damaged by the extra water baths?
