Let's see if @RDspaguy has ever put his hands on one of these.
Specifically, no. But it's just an insulated inground tub, it's not rocket science.
"Leak detection" is like saying "electrical component", it could mean anything. From the diagnosis and lack of location I'm guessing you had a pressure test, which can tell you what part of the system is leaking but not where that leak is physically located in your system. To me, leak detection uses much more specific and sophisticated methods and equipment to locate a specific leak, and these would be the best way to locate yours.
That said, the fact that the spa does not hold pressure is not at all surprising and does not in itself indicate a water leak, depending on how the system was plugged to pressure test it. Every jet has an air line that, with water flowing through the venturi built into the jet, will become a vacuum, drawing in air from a pipe run and valve not designed to hold pressure. To isolate these lines is difficult if not impossible depending on specifics, and if unfamiliar with spa plumbing you'd never know how or even that you needed to. So before digging any more I'd verify that it is in fact leaking water, and how much. If your "shalloe end returns" are in a set of fiberglass steps with a knob on top that could be the source of your pressure leak there too.
The pipe connections will be at the bottom, so 2.5 to 3 ft may not be deep enough, but what you have is schematic, not a diagram. There is no guarantee the pipes even all come out on the same side. There is also no guarantee that the leak is not inside the foam insulation.
Hello! Looking for some help here! We have (I believe) a latham 90” fiberglass spillover spa in a home we purchased last year. Leak detection company came out and said the spa jet lines aren’t holding pressure, and also noted a leak in the shallow end return and valved it off. We dug down 2.5-3 feet in the area that the piping diagram says the pump system should enter the spa but found no pipes!! The whole thing is foam insulated so reaching our hands under the shell and feeling around doesn’t help! I’m wondering if there’s a better place to dig to find the leaking line. Or a better way to be more educated on where to start .
