This is a good one! Our pool is 13000 gals with a raised jacuzzi and a 1 hp Challenger pump. Water flow is directed by Jandy valves. Plumbing (recently redone) is 2" sch 40 and return line does have a 1' bypass around the return valve (some water always returns to spa, even if spa return valve is closed).
We have rentals next door to our house. While out of town, a tenant decided to use our jacuzzi. (Without our permission or the knowledge to operate the pool equipment.) He failed to return the valves to the proper position, resulting in the spa draining and pump running dry. Our neighbor heard the pumps trying to suck water, called us and got water back in the pump.
I need help trying to figure out if any damage was done to the pump/ plumbing. Our neighbor said the motor was warm but not hot. There was no water in spa. Union joint exiting pump was leaking. He tightened the union and it appeared to be okay. A few days later, when we returned, I turned pumps on and union was leaking again, I tighten it and it hasn't leaked for the last 3 days. Motor sounds the same (as far as I can tell). I am worried the damage this caused is something that will become evident after the tenant leaves and has has deposit back. Please, any ideas??