Recently remodeled two showers in the house. We used Moen Posi Temp and balancing Valves. Had them professionally installed. From day one we have only had cold water for 4 minutes then it runs out. Water starts out at 71 degrees and within 10 minutes it is 94 degrees set on a cold setting. We have had numerous plumbers out to figure things out. There are no cross overs. The cartridge has been replaced 5 times in both showers. One plumber just told us he has had other customers with this issue with Moen Posi Valve. He said we could replace it with Kohler or Simmons. I understand if we did that they would have to cut a whole in the wall to get the valves where we tiled the shower. Does anything else have to be replaced other than the two valves? Will the rest of the shower trim package that is moen with work? I hate the added cost but I would like to have the cold water too.