On s single handle tub/shower Moen valve, why I am getting all cold water not matter where the handle is positioned?

Sounds like you have problem with your cartridge, time to replace it please watch the youtubes, Thanks.

John

https://www.youtube.com/watch?v=bEDxl0A2pl0

https://www.youtube.com/watch?v=2bRLEMwznpQ

I echo John's comment. Balancing mechanism inside the cartridge is stuck in one position. Cartridge needs to be replaced

MOEN cartridges are relatively inexpensive and are easy to replace. But the best thing is that if you call MOEN, they may send you replacement cartridge free of charge

Call 1.800.BUY.MOEN

Hope that helps

Milo

Hello Seistakid ,

I agree with Milo, to call Moen and they will send you replacement parts free, Also Please open the PDF below will show you hot to clean the Cartridge, Thanks.

John