Symmons Temptrol shower gradually cools over a few minutes
Great site...I have a Symmons Temptrol shower faucet in 2 bathrooms. One of them works great, we have a hot water tankless furnace and you can take a shower forever in that one without the water cooling off. All of the faucets/appliances and the other shower keep hot water for as long as I've tested them. This one faucet in one shower however, turns on hot, then gradually gets cooler and cooler over just a few minutes, even with the handle turned all the way to hot. I have replaced the entire spindle assembly (T-9 and T-10) brand new, but it didn't change at all. The only thing left in the housing is the hot/cold seats, but I wouldn' think that would effect the water gradually becoming cold, since the "mixing" is done in the spindle assembly.
I should mention, that the house is 4 years old, I purchased 1 year ago and installed a water softner as a result of hard water problems. I beleived this could have resulted in a blockage in the spindle assembly, but like I said, have replaced.
I have searched other similar question, but all answers seem to be the spindle assemble (or cartridge). Any ideas as to what else it could be, or if I'm off my rocker and the hot/cold seats really could be causing this problem. Thanks a bunch!