We have a home that is 3 years old. We never used the 3rd bathroom shower until today. We have a Moen single knobe shower/bath valve. To get water from the faucet you pull the knob out. To adjust the water temp - Left for hot and right for cold. When rotated to the left for hot the water shuts off. When rotated to the right we get only cold water. Could the valve be installed wrong or could the cartridge be installed wrong? Kevin

we would need a little more information but sounds like it will need replacement, The water will eat up the meatle and make a rebuild impossible sorry but no quick fix the hot water lineis usley the culprit

to valve is failing [need to replace the valve ]]or debris is stuck in valve either way would need to remove the valve body to inspect

Good news MOEN has a lifetime warranty shut water off to shower then remove the valve behind the knob home Depot or lowes give you new one free with old part

Sounds like the cause of your problem is the pressure balancing spool. Call Moen at
1-800-289-6636 and explain the problem. They will send a repair part to you free of charge. the link below is a "blow up" of your valve.

http://www.moen.com/shared/pdf/t3113pt.pdf

Only two possibilities here the diverter tub spout is not open all the way to let water to the tub only or the shower valve is installed up-side-down.

http://www.moen.com/shared/pdf/l82691pt.pdf

probably have a kink on how water line feeding valve..if possible to cut drywall bhind tub valve and inspect pipe at bottom plate...moen faucets are equipped w/ anti scald device, pressure balanced (newer models) and this could cause cold water to overwhelm hot water...

no but you will get a cross conection problem

Yup.......Take it a part..single handle..?..remove the temperature set ring ..replace...Send $50.00 to me..heheheheh

Single handle shower controls always have some water trapped inside. It has probably freeze damaged the cartridge

The Moen Posi-Temp Valve is a pressure balanced valve and when not used for long periods of time they can stick causing only cold or hot water to pass through the valve.
A New Posi-temp cartridges can be purchased at most plumbing supply houses or big box outlets such as Lowes or Home Depot.
As long as you had cold water before, a new cartridge will solve the problem. In the future it would be wise to occassionally operate the valve at least a couple of times a month in order to keep the pressure assembly from becoming lodged in position. Just follow the instructions included with the new cartridge on the proper removal of the old cartridge and the installation of the new cartridge. a little silicone grease inside of the valve before installing the new cartridge will also help.
Be sure that there is no particles of the old cartridge left in the valve.
sanray