MEP001
Well-known member
Assuming the tank that's overflowing is hot water, the easiest way to find it is to run all the pumps on soap until the check valves are hot to the touch, then turn them off and turn on the weep. Whichever one/ones is/are leaking back will get cold. You can do one or two bays at a time - I'm usually at the wash late enough that I can tie off all the guns and check them all at once.