……………….you would need a mirror to see it.
That's exactly what I had to do, use a mirror. When I turned the pump on and pressurized the system, it pumped up and cut off. A few minutes later, I heard just a "burp" from the pump. About 3 minutes later, I heard it again, and I became suspect. Looked under the kitchen cabinet and saw a small puddle of water under the valves at the water heater. Didn't know which one was leaking, but I could hear a faint "hissing" noise. When I put the inspection mirror behind it, it got wet from the very fine spray that was coming out. With a closer look, I saw the O-ring sticking out. Glad it was still sitting in our driveway and not out on the road. Got to use that spare valve I had bought from our previous TT.
I repressurized the system with the pump, turned pump off for 24 hours and then flipped it back on. The pump didn't start, so apparently no more leaks. I now have a plexiglass inspection window in the panel covering the water heater so I can do routine inspections without taking the panel off.
Randy, Karen & Abby (Pom-a-Poo)
2014 Eagle HT 27.5RLTS
2015 F250 Super duty 6.2L full trailering pkg.
Shenandoah Valley of Virginia