Symmons Temptrol repair:
Tenant threw us this one today, 20 year old Symmons Temptrol hard to turn. When I arrived handle and splined end of cartridge broken off, so off to the plumbing supply for a T10 cartridge, and a new cap, easy right? So I unscrew the whole thing together and turn the water back on, works great except I cannot turn the water off at the tub, wtf? So I screw the T-10 and compare with the old, the difference being the thick rubber gasket on the old cartridge that mates to the outer (cold?) seat, vs. the new T-10 which has a steel washer with a rubber center. I have heard of the seats being a problem, and actually recalled some years ago? Would a seat change do it? Thanks!