Hoffman 75 failing?
Chasing water loss on my mother-in-law's one pipe system. Two mains, one with big mouths and the other with a Hoffman 75. During a long cycle, the big mouths will close and stay closed but the Hoffman will Cycle open and closed throughout the cycle.
I suspect the element is going bad because the vent will not stay closed. Any suggestions as to what other Main vent has a similar capacity to a 75?
Kind of a bummer as the Hoffman is only a few years old.
