I'm thinking the outside shower is where my leak is in and/or around the UDC. Can't really find exactly where it's leaking, but once I found the shower head turned on, but the knobs were turned off...shower head was leaking water, sometimes I'll also find water inside the UDC. We have never used the outside shower, so I don't know how the shower head got turned on. I've found the floor of the basement around the UDC soaking wet & had to use a wet vac to get it dried out. I'm planning on putting shut off valves on the back of the UDC on the inlet hoses for the hot & cold water when it warms up.