Need help with shower !

[Atrox]

My shower is cold for 5-20 seconds then it can get to warm and it won't go back to cold.

Hot works and warm works but when i move it to max cold it wont work it just gives me warm water

pictures of water heater

http://gyazo.com/1dbe0decce5ad3f6380b976addad4fe4

http://gyazo.com/813ac3fab26ab33074448de3d9c3f60f

http://gyazo.com/07efd4a80fc6aa6eae8caf79091a93e1

 

[texasholden]

If it's only affecting your shower then it's not your system, it's likely to be the thermostatic cartridge in your shower valve.

 

[Atrox]

If it's only affecting your shower then it's not your system, it's likely to be the thermostatic cartridge in your shower valve.

ok is it a twist off and on?

 

[picasso]

Is your shower existing or a new one ?

 

[Atrox]

Is your shower existing or a new one ?

existing

 

[Atrox]

If it's only affecting your shower then it's not your system, it's likely to be the thermostatic cartridge in your shower valve.

texas, would you need a picture to know what it is?

 

[texasholden]

a photo would help. Normally they're directly behind the thermo control and either screw in or simply push in (snug fit).