Shower is freezing, how to I adjust the temp valve?

[jayson]

Just moved into a new house, and no matter what I do the shower is lukewarm at best! At first I thought it may be the water heater, but water comes out very hot from the tub (adjacent to the shower). This lead me to finding the temperature control valve, but I have no idea what the heck to do with this. Any advice please? (See attached image)

[jayson]

Forgot to mention, I believe it is a Moen faucet.

[Plumber Jim]

you have 2 stops on that valve one on the right and one on the left. use a screw driver and make sure the left one assuming its not backwards is open all the way.

[jayson]

you have 2 stops on that valve one on the right and one on the left. use a screw driver and make sure the left one assuming its not backwards is open all the way.

So - turn the left one fully counter clockwise?

[jayson]

okay, tried it out & those things seem to just turn the water from that valve on or off.

(|) is off
(-) is on

Both were already set at the "full on" position.

[Basement_Lurker]

Yes, you are correct, those are just shutoffs. Sometimes they are not opened fully by the installer, which is why you were told to make sure they are open fully.

There is no high limit on that valve. Your cartridge is probably in need of replacement.

[jayson]

So they will just spin around indefinitly, correct?

What is the cartridge and how is it replaced? Sorry for my newbie-ness.

[Plumber Jim]

If you put the handle on without the rest of the trim and turn it can you get hot water? also you can turn off both valves and pull the clip on the top that holds the cartridge in and then remove the cartridge and open the hot side and see if you have pressure there the close and do the same on the cold and compare. If they are the same pressure then replace the cartridge.